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Core Java for Selenium

Core Java for Selenium

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Core Java for Selenium

  1. 1. WWW.PAVANONLINETRAININGS.COM | WWW.PAVANTESTINGTOOLS.COM
  2. 2. About Java • It is one of the programming language or technology used for developing web applications. • Using this technology you can develop distributed application. • A Java language developed at SUN Micro Systems in the year 1995 under the guidance of James Gosling and their team. • In other word It is a programming language suitable for the development of web applications. • It is also used for developing desktop and mobile application. 2
  3. 3. Java Version History • JDK Alpha and Beta (1995) • JDK 1.0 (23rd Jan, 1996) • JDK 1.1 (19th Feb, 1997) • J2SE 1.2 (8th Dec, 1998) • J2SE 1.3 (8th May, 2000) • J2SE 1.4 (6th Feb, 2002) • J2SE 5.0 (30th Sep, 2004) • Java SE 6 (11th Dec, 2006) • Java SE 7 (28th July, 2011) • Java SE 8 (18th March, 2014) 3
  4. 4. Download and Install Java8 • http://www.oracle.com/technetwork/java/javase/downloads/index.html 4 STEP 1 STEP 2
  5. 5. 5 STEP 3 STEP 4
  6. 6. 6 STEP 5 STEP 6
  7. 7. First Java Program 7 class First { public static void main(String[] args) { System.out.println("Hello Java"); System.out.println("My First Java Program"); } }
  8. 8. Compile and Run Java Program 8
  9. 9. Difference between JDK, JVM and JRE • JDK has all the tools used for develop applications. • JVM is responsible for compiling and executing Java programs. • JRE provides environment to run Java Applications. 9
  10. 10. Data Types in Java 10 Data Type Default Value Default size boolean false 1 bit char 'u0000' 2 byte byte 0 1 byte short 0 2 byte int 0 4 byte long 0L 8 byte float 0.0f 4 byte double 0.0d 8 byte
  11. 11. Operators 11 Operator Type Operators Arithmetic + - * / % Relational < > <= >= != == Logical && || ! Assignment == += *= /= %= Increment ++ Decrement --
  12. 12. Assignment-1 (Data types and Operators) 1. Write a Java program to print 'Hello' on screen and then print your name on a separate line. 2. Write a Java program to print the sum of two numbers. 3. Write a Java program to print the sum (addition), multiply, subtract, divide and remainder of two numbers. 4. Write a Java program to swap two numbers. 12
  13. 13. Conditional Statements • if statement • if-else statement • Nested if (IF-else-if) statement • Switch case 13
  14. 14. If Statement • Syntax: if(condition) { //code to be executed } 14 Example: public class IfExample { public static void main(String[] args) { int age=20; if(age>18){ System.out.print("Age is greater than 18"); } } }
  15. 15. If Else statement • Syntax: if(condition) { //code if condition is true } else { //code if condition is false } 15 Example: public class IfElseExample { public static void main(String[] args) { int number=13; if(number%2==0){ System.out.println("even number"); }else{ System.out.println("odd number"); } } }
  16. 16. IF-else-if • Syntax: if(condition1){ //code to be executed if condition1 is true }else if(condition2){ //code to be executed if condition2 is true } else if(condition3){ //code to be executed if condition3 is true } ... else{ //code to be executed if all the conditions are fals e } 16 public class IfElseIfExample { public static void main(String[] args) { int marks=65; if(marks<50){ System.out.println("fail"); } else if(marks>=50 && marks<60){ System.out.println("D grade"); } else if(marks>=60 && marks<70){ System.out.println("C grade"); } else if(marks>=70 && marks<80){ System.out.println("B grade"); } else if(marks>=80 && marks<90){ System.out.println("A grade"); }else if(marks>=90 && marks<100){ System.out.println("A+ grade"); }else{ System.out.println("Invalid!"); } } }
  17. 17. Switch Statement • Syntax: switch(expression){ case value1: //code to be executed; break; case value2: //code to be executed; break; ...... default: code to be executed if all cases are not matched; } 17 Example: public class SwitchExample { public static void main(String[] args) { int number=20; switch(number) { case 10: System.out.println("10");break; case 20: System.out.println("20");break; case 30: System.out.println("30");break; default:System.out.println("Not in 10, 2 0 or 30"); } } }
  18. 18. Assignment-2(Conditional statements) 1. Write a Java program to check a number is even or odd. 2. Write a Java program that prints weekday based the week number(1 to 7). 3. Print the greatest number of 3 numbers. 4. Write a Java program to check whether number is negative, zero, or positive. 5. Write a program will show if the person is eligible to vote. 6. Write a program to print month name based month number as an input using switch...Case statement. 18
  19. 19. Loops • While • Do..while • For loop 19
  20. 20. 20 While loop • Syntax: while(condition){ //code to be executed } Example: public class WhileExample { public static void main(String[] args) { int i=1; while(i<=10){ System.out.println(i); i++; } } }
  21. 21. Do..while loop • Syntax: do{ //code to be executed }while(condition); 21 • Example: public class DoWhileExample { public static void main(String[] args) { int i=1; do{ System.out.println(i); i++; }while(i<=10); } }
  22. 22. For loop • Syntax: for(initialization;condition;incr/decr) { //code to be executed } 22 • Example: public class ForExample { public static void main(String[] args) { for(int i=1;i<=10;i++){ System.out.println(i); } } }
  23. 23. For-each Loop • Syntax: for(Type var:array) { //code to be executed } 23 • Example: public class ForEachExample { public static void main(String[] args) { int arr[]={12,23,44,56,78}; for(int i:arr){ System.out.println(i); } } }
  24. 24. Java Break Statement • The Java break is used to break loop or switch statement. It breaks the current flow of the program at specified condition. In case of inner loop, it breaks only inner loop. • Syntax: jump-statement; break; 24 Output: 1 2 3 4 Example: public class BreakExample { public static void main(String[] args) { for(int i=1;i<=10;i++){ if(i==5){ break; } System.out.println(i); } } }
  25. 25. Java Break Statement with Inner Loop • It breaks inner loop only if you use break statement inside the inner loop. • Example: 25 • Output: 1 1 2 2 1 3 2 1 3 1 3 2 3 3 public class BreakExample2 { public static void main(String[] args) { for(int i=1;i<=3;i++){ for(int j=1;j<=3;j++){ if(i==2&&j==2){ break; } System.out.println(i+" "+j); } } } }
  26. 26. Java Continue Statement • The Java continue statement is used to continue loop. It continues the current flow of the program and skips the remaining code at specified condition. In case of inner loop, it continues only inner loop. • Syntax: jump-statement; continue; 26 Output: 1 2 3 4 6 7 8 9 10 Example: public class ContinueExample { public static void main(String[] args) { for(int i=1;i<=10;i++){ if(i==5){ continue; } System.out.println(i); } } }
  27. 27. Java continue Statement with Inner Loop • It continues inner loop only if you use continue statement inside the inner loop. • Example: 27 • Output: 1 1 2 2 1 3 2 1 2 3 3 1 3 2 3 3 public class ContinueExample2 { public static void main(String[] args) { for(int i=1;i<=3;i++){ for(int j=1;j<=3;j++){ if(i==2&&j==2){ continue; } System.out.println(i+" "+j); } } } }
  28. 28. Assignment-3(Loops) 1. Write a program in Java to display the first 10 natural numbers in ascending order using while loop. 2. Write a program in Java to display the first 10 natural numbers in descending order using do..while loop. 3. Write a program in Java to display the multiplication table of a number using for loop. 4. Write a java program to split number into digits. 5. Write a java program to sum digits of a number. 6. Write a java program to reverse a number. 28
  29. 29. Arrays • Array is a collection of similar type of elements that have contiguous memory location. • Java array is an object the contains elements of similar data type. It is a data structure where we store similar elements. • We can store only fixed set of elements in a java array. • Array in java is index based, first element of the array is stored at 0 index. 29
  30. 30. Types of Arrays • There are two types of array. • Single Dimensional Array • Multidimensional Array 30
  31. 31. Single Dimensional Array in java • Syntax to Declare an Array in java dataType[] arr; (or) dataType []arr; (or) dataType arr[]; • Instantiation of an Array in java arrayRefVar=new datatype[size]; 31 • Example to Declare an Array in java int[] a; (or) int []a; (or) int a[]; • Instantiation of an Array in java a=new datatype[size]; • Declaration with instantiation Int a[]=new int[];
  32. 32. Example of single dimensional java array • Example of java array, where we are going to declare, instantiate, initialize and traverse an array. 32 class Testarray{ public static void main(String args[]){ int a[]=new int[5]; //declaration and instantiation a[0]=10; //initialization a[1]=20; a[2]=70; a[3]=40; a[4]=50; //printing array for(int i=0;i<a.length;i++)//length is the property of array System.out.println(a[i]); } }
  33. 33. Multidimensional array in java • data is stored in row and column based index (also known as matrix form). • Syntax to Declare Multidimensional Array in java dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; • Example to instantiate Multidimensional Array in java int[][] arr=new int[3][3]; //3 rows and 3 columns 33
  34. 34. Example of Multidimensional java array • Example to declare, instantiate, initialize and print the 2Dimensional array. 34 • Output: 1 2 3 2 4 5 4 4 5 class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j=0;j<3;j++){ System.out.print(arr[i][j]+" "); } System.out.println(); } } }
  35. 35. Limitations in an array • Array is fixed limit. • We should know size of an array before declaration. • Array cannot hold multiple datatype elements. 35
  36. 36. Object class in Java • Object is the pre-defined main class of all the Java classes. • We can create a variable with Object type, it can hold any data type values. • For Example: Object a; a=10; a=“Welcome”; a=15.5; • We can also create Object type array. 36
  37. 37. Object type array • Syntax to Declare an Object type Array Object[] obj; (or) Object []obj; (or) Object obj[]; • Instantiation of an Array in java obj=new Object[size]; 37 • Example to Declare an Object type Array Object[] a; (or) Object []a; (or) Object a[]; • Instantiation of an Array in java a=new Object[size]; • Declaration with instantiation Object a[]=new Object[];
  38. 38. Example of single dimensional Object Type array • Example of Object type java array, where we are going to declare, instantiate, initialize and traverse an array. 38 class TestObjectArray{ public static void main(String args[]){ Object a[]=new Object[5]; //declaration and instantiation a[0]=10; //initialization a[1]=20.5; a[2]=“Welcome”; a[3]=‘A’; a[4]=true; //printing array for(int i=0;i<a.length;i++)//length is the property of array System.out.println(a[i]); } }
  39. 39. Assignment-4(Arrays) 1. Define a single dimensional array and store some values and read them using for loop. 2. Define a single dimensional array and store some values and read them using for…each loop. 3. Define a single array with 5 elements and Search an element present or not in the array. 4. Define a string array with 5 strings and search for a string in the array. 5. Define string array with 5 strings and print them using for..each loop. 6. Define two-dimensional array with 3 rows and 3 columns and read all the values using classic for loop. 7. Do the 6th program using for each loop (enhanced loop) 8. Define an Object array with multiple data type values and print them using for..each loop. 39
  40. 40. String class in java • Generally, string is a sequence of characters. But in java, string is an object that represents a sequence of characters. • The java.lang.String class is used to create string object. • Create a String object in 2 ways. • String s=“Welcome”; • String s=new String(“Welcome”); • char ch[]={‘w',‘e',‘l',‘c',‘o',‘m',‘e'}; • String s=new String(ch); //converting char array to string 40
  41. 41. Java String Example 41 public class StringExample{ public static void main(String args[]){ String s1="java";//creating string by java string literal char ch[]={'s','e','l','e','n','i','u','m'}; String s2=new String(ch);//converting char array to string String s3=new String("training");//creating java string by new keyword System.out.println(s1); System.out.println(s2); System.out.println(s3); }}
  42. 42. String Methods 42 • chatAt() • length() • contains() • equals() • equalsIgnoreCase() • isEmpty() • replace() • concat() • toUpperCase() • toLowerCase() • substring() • split()
  43. 43. • charAt(): Returns a char value at the given index number. The index number starts from 0 Output : o 43 public class CharAtExample{ public static void main(String args[]){ String name="Welcome"; char ch=name.charAt(4); //returns the char value at the 4th index System.out.println(ch); } }
  44. 44. • Concat() : Combines specified string at the end of this string. It returns combined string • Output: Welcome Welcome to java training 44 public class ConcatExample{ public static void main(String args[]){ String s1="Welcome"; System.out.println(s1); s1=s1.concat(" to java training"); System.out.println(s1); }}
  45. 45. • contains() : searches the sequence of characters in this string. It returns true if sequence of char values are found in this string otherwise returns false. Output: true true false 45 class ContainsExample{ public static void main(String args[]){ String name="what do you know about me"; System.out.println(name.contains("do you know")); System.out.println(name.contains("about")); System.out.println(name.contains("hello")); }}
  46. 46. • equals() : compares the two given strings based on the content of the string. If any character is not matched, it returns false. If all characters are matched, it returns true. 46 public class EqualsExample{ public static void main(String args[]){ String s1="welcome"; String s2="welcome"; String s3="WELCOME"; String s4="training"; System.out.println(s1.equals(s2));//true because content and case is same System.out.println(s1.equals(s3));//false because case is not same System.out.println(s1.equals(s4));//false because content is not same } }
  47. 47. • equalsIgnoreCase(): compares the two given strings on the basis of content of the string irrespective of case of the string. It is like equals() method but doesn't check case. If any character is not matched, it returns false otherwise it returns true. 47 public class EqualsExample{ public static void main(String args[]){ String s1="welcome"; String s2="welcome"; String s3="WELCOME"; String s4="training"; System.out.println(s1.equalsIgnoreCase(s2));//true because content is same System.out.println(s1.equalsIgnoreCase(s3));//true because case is ignored System.out.println(s1.equalsIgnoreCase(s4));//false because content is not same } }
  48. 48. • length(): length of the string. It returns count of total number of characters. The length of java string is same as the unicode code units of the string. 48 public class LengthExample{ public static void main(String args[]){ String s1="welcome"; String s2="python"; System.out.println("string length is: "+s1.length());//7 System.out.println("string length is: "+s2.length());//6 } }
  49. 49. • replace(): Returns a string replacing all the old char or CharSequence to new char or CharSequence. 49 public class ReplaceExample1{ public static void main(String args[]){ String s1="software testing is a very course"; String replaceString=s1.replace('a','e');//replaces all occu rrences of 'a' to 'e' System.out.println(replaceString); }}
  50. 50. • split(): splits this string against given regular expression and returns a char array. 50 public class SplitExample{ public static void main(String args[]){ String s1="java string split method "; String[] words=s1.split("s");//splits the string based on whitespace //using java foreach loop to print elements of string array for(String w:words){ System.out.println(w); } } }
  51. 51. • substring() : returns a part of the string. • We pass begin index and end index number position in the java substring method where start index is inclusive and end index is exclusive. In other words, start index starts from 0 whereas end index starts from 1. • Parameters • startIndex : starting index is inclusive • endIndex : ending index is exclusive 51 public class SubstringExample{ public static void main(String args[]){ String s1="javatpoint"; System.out.println(s1.substring(2,4));//returns va System.out.println(s1.substring(2));//returns vatpoint } }
  52. 52. • toLowerCase(): returns the string in lowercase letter. In other words, it converts all characters of the string into lower case letter. 52 public class StringLowerExample { public static void main(String args[]) { String s1="Welcome to TRAINING"; String s1lower=s1.toLowerCase(); System.out.println(s1lower); } }
  53. 53. • toUpperCase(): returns the string in uppercase letter. In other words, it converts all characters of the string into upper case letter. 53 public class StringUpperExample { public static void main(String args[]) { String s1="hello string"; String s1upper=s1.toUpperCase(); System.out.println(s1upper); } }
  54. 54. • valueOf() : converts different types of values into string. By the help of string valueOf() method, you can convert int to string, long to string, boolean to string, character to string, float to string, double to string, object to string and char array to string. 54 public class StringValueOfExample{ public static void main(String args[]) { int value=30; String s1=String.valueOf(value); System.out.println(s1+10);//concatenating string with 10 } }
  55. 55. Java - Date and Time • Java provides the Date class available in java.util package. • Date( ) • This constructor initializes the object with the current date and time. 55
  56. 56. Getting Current Date and Time 56 import java.util.Date; public class DateDemo { public static void main(String args[]) { // Instantiate a Date object Date date = new Date(); // display time and date using toString() System.out.println(date.toString()); } }
  57. 57. Assignment-5(String methods) 1. Write a Java program to get the character at the given index within the String. 2. Write a Java program to concatenate two strings. 3. Write a Java program to test if a given string contains the specified sequence of char values. 4. Write a Java program to compare a given strings. 5. Write a Java program to compare a given string to another string, ignoring case considerations. 6. Write a java program to get the length of a given string. 7. Java program to remove vowels from a string. 57
  58. 58. 8. Define a string variable called ‘s’ s=" Welcome to selenium java training" Do the following: • Count how many words are present in a string. • Display all the words in upper case • Display all the words in lower case • Verify presence of "selenium" • Display all the words in reverse order 58
  59. 59. Classes and Objects • A class is a group of objects which have common properties. It is a template or blueprint from which objects are created. • It is a logical entity. It can't be physical. • A class in Java can contain: • fields • methods • constructors • Syntax to declare a class: class <class_name>{ field; method; } 59
  60. 60. Objects • Object is the physical as well as logical entity whereas class is the logical entity only. • Object is an instance of a class. Class is a template or blueprint from which objects are created. So object is the instance(result) of a class. • Object Definitions: • Object is a real world entity. • Object is a run time entity. • Object is an entity which has state and behavior. • Object is an instance of a class. 60
  61. 61. 61
  62. 62. Object and Class Example: main within class File: Student.java 62 class Student{ int id=101; //field or data member or instance variable String name=“Anil”; public static void main(String args[]){ Student s1=new Student();//creating an object of Student System.out.println(s1.id);//accessing member through reference variable System.out.println(s1.name); } }
  63. 63. Object and Class Example: main outside class • In real time development, we create classes and use it from another class. It is a better approach than previous one. • We can have multiple classes in different java files or single java file. • If you define multiple classes in a single java source file, it is a good idea to save the file name with the class name which has main() method. 63
  64. 64. File: TestStudent1.java 64 class Student{ int id=101;; String name=“Anil; } class TestStudent1{ public static void main(String args[]){ Student s1=new Student(); System.out.println(s1.id); System.out.println(s1.name); } }
  65. 65. 3 Ways to initialize object • There are 3 ways to initialize object in java. • By reference variable • By method • By constructor 65
  66. 66. Object and Class Example: Initialization through reference • File: TestStudent2.java 66 class Student{ int id; String name; } class TestStudent2{ public static void main(String args[]){ Student s1=new Student(); s1.id=101; s1.name=“Anil"; System.out.println(s1.id+" "+s1.name);//printing members with a white space } }
  67. 67. Object and Class Example: Initialization through method 67 File: TestStudent4.javaclass Student{ int rollno; String name; void insertRecord(int r, String n) { rollno=r; name=n; } void displayInformation() { System.out.println(rollno+" "+name); } } class TestStudent4{ public static void main(String args[]) { Student s1=new Student(); Student s2=new Student(); s1.insertRecord(111,"Karan"); s2.insertRecord(222,"Aryan"); s1.displayInformation(); s2.displayInformation(); } }
  68. 68. Object and Class Example: Initialization through constructor 68 File: TestStudent5.javaclass Student{ int rollno; String name; void Student(int r, String n){ rollno=r; name=n; } void displayInformation() { System.out.println(rollno+" "+name); } } class TestStudent4{ public static void main(String args[]){ Student s1=new Student(111,”Kiran”); Student s2=new Student(222,”arya”); s1.displayInformation(); s2.displayInformation(); } }
  69. 69. Passing parameters to the methods • Call by value • Call by reference 69
  70. 70. Call by Value 70 public class ByVal { int x; public void addition(int a) { x = a + 5; } } public class CallByVal { public static void main(String args[]) { ByVal b=new ByVal(); Int x=10; b.addition(x); System.out.println(x); // 10 } }
  71. 71. Call by Reference 71 public class ByRef { int x; public void addition(ByRef a) { x = a.x + 5; } } public class CallByRef { public static void main(String args[]) { ByRef b=new ByRef(); Int b.x=10; b.addition(b); System.out.println(b.x); //15 } }
  72. 72. Assignment-6 (Class and Objects) 1. Create an Employee class contains the following variables and methods. Class Name: Employee: EmpID Ename Esal Job getEmpData()  Should take the Employee details externally and assign them to class variables displayEmpData()  Should display the employee details Now, create objects from Employee class emp1, emp2 etc. Then call Employee class methods by passing values. 72
  73. 73. 2. Create a Student class contains the following variables and methods. Class Name: Student SID Sname Sub1 Sub2 Sub3 getStuData()  Should take the Student details SID and Sname externally and assign them to class variables getStuMarks()  Should take the Student marks externally and assign them to Sub1, Sub2, Sub3 CalTotalMarks()  Should calculate total marks and print the student details with total marks Now, create objects from Student class stu1, stu2 etc. Then call Student class methods by passing values. 73
  74. 74. Java Constructor • Constructor in java is a special type of method that is used to initialize the object. • Java constructor is invoked at the time of object creation. • Rules for creating java constructor: • Constructor name must be same as its class name • Constructor must have no explicit return type • Types of java constructors • Default constructor (no-arg constructor) • Parameterized constructor 74
  75. 75. Default constructor • A constructor that have no parameter is known as default constructor. • Example of default constructor. 75 class Bike1 { Bike1() { System.out.println("Bike is created"); } public static void main(String args[]) { Bike1 b=new Bike1(); } }
  76. 76. Parameterized constructor • A constructor that have parameters is known as parameterized constructor. • Parameterized constructor is used to provide different values to the distinct objects. 76
  77. 77. Example of parameterized constructor 77 class Student4{ int id; String name; Student4(int i, String n){ id = i; name = n; } void display() { System.out.println(id+" "+name); } public static void main(String args[]) { Student4 s1 = new Student4(111,"Karan"); Student4 s2 = new Student4(222,"Aryan"); s1.display(); s2.display(); } }
  78. 78. Assignment-7 (Constructors) 1. Write a program to demonstrate constructor. Create a class ‘Calculation’ with 3 integer variables and create constructor for assign the values into variables. Then create another method to calculate sum of 3 numbers. 2. Write a program to demonstrate constructor overloading. Create a class with name ‘Sum’ with 5 i variables and create constructors as following. Variables: integers  a b doubles  c d Define constructor for take 2 integers as input and assign to a, b Define constructor for take 2 double as input and assign to c, d Define a method for adding two numbers. 78
  79. 79. Method Overloading • If a class has multiple methods having same name but different in parameters, it is known as Method Overloading. • Different ways to overload the method • By changing number of arguments • By changing the data type 79
  80. 80. Method Overloading: changing no. of arguments 80 class Adder{ int add(int a,int b) { return a+b; } int add(int a,int b,int c) { return a+b+c; } } class TestOverloading1 { public static void main(String[] args) { Adder ad=new Adder(); System.out.println(ad.add(11,11)); System.out.println(ad.add(11,11,11)); } }
  81. 81. Method Overloading: changing data type of arguments 81 class Adder{ int add(int a,int b) { return a+b; } int add(double a,double b) { return a+b; } } class TestOverloading2 { public static void main(String[] args) { Adder ad=new Adder(); System.out.println(ad.add(11,11)); System.out.println(ad.add(11.5,12.5)); } }
  82. 82. Can we overload java main() method? • Yes, by method overloading. You can have any number of main methods in a class by method overloading. But JVM calls main() method which receives string array as arguments only. 82 class TestOverloading4 { public static void main(String[] args) { System.out.println("main with String[]"); } public static void main(String args) { System.out.println("main with String"); } public static void main() { System.out.println("main without args"); } }
  83. 83. Constructor Overloading in Java 83 class Student5 { int id; String name; int age; Student5(int i,String n){ id = i; name = n; } Student5(int i,String n,int a){ id = i; name = n; age=a; } void display() { System.out.println(id+" "+name+" "+age); } public static void main(String args[]){ Student5 s1 = new Student5(111,"Karan"); Student5 s2 = new Student5(222,"Aryan",25); s1.display(); s2.display(); } }
  84. 84. Assignment-8(Overloading) 1. Create a class Calculation with the following methods. (Method Overloading concept) Class Name: Calculation sum(int x, int y)  Should accept two integer parameters and returns sum of two numbers. sum(int x, int y, int z)  Should accept three integer parameters and returns sum of three numbers. sum(double x, double y)  Should accept two double type parameters and returns sum of two numbers. sum(double x, double y, double z)  Should accept three double type parameters and returns sum of three numbers. Now, create object for Calculations class ‘cal’ then call different methods by passing different inputs. 84
  85. 85. Static variables and static methods • Static methods can access static methods and static variables directly with class name. • Static methods can access Non static methods and non static variables using object. • Non static methods can access static and non static variable and methods directly with class name. • Static keyword should be used for defining static variables and methods. • Static variable values are common across the all the objects for the class. 85
  86. 86. Assignment-9 (static variables and methods) 1. Write a program to demonstrate static methods and static variables as follows. • Define a Class A contains 2 static integer variables and one static method which displays sum of two numbers. • Try to access variables and method from another static method i.e main method. 86
  87. 87. Java Inheritance • Inheritance in java is a mechanism in which one object acquires all the properties and behaviors of parent object. • The idea behind inheritance in java is that you can create new classes that are built upon existing classes. • When you inherit from an existing class, you can reuse methods and fields of parent class, and you can add new methods and fields also. • Syntax of Java Inheritance class Subclass-name extends Superclass-name { //methods and fields } 87
  88. 88. Types of inheritance • Single inheritance • Multilevel inheritance • Hierarchical inheritance • Multiple inheritance • Hybrid inheritance 88
  89. 89. 89
  90. 90. Method Overriding in Java • If subclass (child class) has the same method as declared in the parent class, it is known as method overriding in java. • Rules for Java Method Overriding • method must have same name as in the parent class • method must have same parameter as in the parent class. 90
  91. 91. Example of method overriding Output: Bike is running safely 91 class Vehicle{ void run(){System.out.println("Vehicle is running");} } class Bike2 extends Vehicle{ void run(){System.out.println("Bike is running safely"); } public static void main(String args[]){ Bike2 obj = new Bike2(); obj.run(); }
  92. 92. Real example of Java Method Overriding 92
  93. 93. 93 Output: SBI Rate of Interest: 8 ICICI Rate of Interest: 7 AXIS Rate of Interest: 9 class Bank{ int getRateOfInterest(){return 0;} } class SBI extends Bank{ int getRateOfInterest(){return 8;} } class ICICI extends Bank{ int getRateOfInterest(){return 7;} } class AXIS extends Bank{ int getRateOfInterest(){return 9;} } class Test2{ public static void main(String args[]){ SBI s=new SBI(); ICICI i=new ICICI(); AXIS a=new AXIS(); System.out.println("SBI Rate of Interest: "+s.getRateO fInterest()); System.out.println("ICICI Rate of Interest: "+i.getRat eOfInterest()); System.out.println("AXIS Rate of Interest: "+a.getRate OfInterest()); } }
  94. 94. super keyword in java • The super keyword in java is a reference variable which is used to refer immediate parent class object. • Usage of java super Keyword 1) super can be used to refer immediate parent class instance variable. 2) super can be used to invoke immediate parent class method. 3) super() can be used to invoke immediate parent class constructor. 94
  95. 95. super is used to refer immediate parent class instance variable. 95 class Animal{ String color="white"; } class Dog extends Animal{ String color="black"; void printColor(){ System.out.println(color);//prints color of Dog class System.out.println(super.color);//prints color of Animal class } } class TestSuper1{ public static void main(String args[]){ Dog d=new Dog(); d.printColor(); }}
  96. 96. super can be used to invoke parent class method 96 class Animal{ void eat(){System.out.println("eating...");} } class Dog extends Animal{ void eat(){System.out.println("eating bread..." );} void bark(){System.out.println("barking...");} void work(){ super.eat(); bark(); } } class TestSuper2{ public static void main(String args[]){ Dog d=new Dog(); d.work(); }}
  97. 97. super is used to invoke parent class constructor. 97 class Animal{ Animal(){System.out.println("animal is created" );} } class Dog extends Animal{ Dog(){ super(); System.out.println("dog is created"); } } class TestSuper3{ public static void main(String args[]){ Dog d=new Dog(); } }
  98. 98. Final Keyword In Java • The final keyword in java is used to restrict the user. The java final keyword can be used for variables, methods and classes. • variable • method • class 98
  99. 99. Java final variable • If you make any variable as final, you cannot change the value of final variable(It will be constant). • Example of final variable • Output:Compile Time Error 99 class Bike9{ final int speedlimit=90;//final variable void run(){ speedlimit=400; } public static void main(String args[]){ Bike9 obj=new Bike9(); obj.run(); } }//end of class
  100. 100. Java final method • If you make any method as final, you cannot override it. • Example of final method 100 class Bike{ final void run(){System.out.println("running");} } class Honda extends Bike{ void run(){System.out.println("running safely with 100kmph");} public static void main(String args[]){ Honda honda= new Honda(); honda.run(); } } Output:Compile Time Error
  101. 101. Java final class • If you make any class as final, you cannot extend it. • Example of final class • Output:Compile Time Error 101 final class Bike{} class Honda1 extends Bike{ void run(){System.out.println("running safely with 100kmph");} public static void main(String args[]){ Honda1 honda= new Honda(); honda.run(); } }
  102. 102. Assignment-10 (Inheritance) 1. Write a program to demonstrate Single Inheritance. • Class A int a, int b m1() m2() • Class B  int c, int d m3() m4() • Class Test  try to access all the variables and methods from parent classes. • Note: Class B should extends from Class A, Class Test should extends from Class B. 102
  103. 103. 2. Write a program to demonstrate Multi level Inheritance with method over riding concept. • Class A Define two methods m1() and m2(). • Class B  Change body of m1() & m2() methods (override) • Class Test  try to access all the variables and methods from parent classes. • Note: Class B should extends from Class A, Class Test should extends from Class B. 103
  104. 104. 3. Write a program to demonstrate Hierarchy Inheritance. • Class A int a, int b m1() m2() • Class B  int c, int d m3() m4() • Class Test  try to access all the variables and methods from parent classes. • Note: Class Test should extends from Class A, Class B should extends from Class A. 104
  105. 105. Java Interfaces • An interface in java is a blueprint of a class. It has static constants and abstract methods. • By interface, we can support the functionality of multiple inheritance. • We can define interface with interface keyword. • A class extends another class, an interface extends another interface but a class implements an interface. • We can create Object reference for Interface but we cannot instantiate interface. 105
  106. 106. Java Interface Example 106 interface printable{ void print(); } class A6 implements printable { public void print(){System.out.println("Hello"); } public static void main(String args[]){ A6 obj = new A6(); obj.print(); } }
  107. 107. Java Interface Example: Bank TestInterface2.java 107 interface Bank{ float rateOfInterest(); } class SBI implements Bank{ public float rateOfInterest(){return 9.15f;} } class PNB implements Bank{ public float rateOfInterest(){return 9.7f;} } class TestInterface2{ public static void main(String[] args){ Bank b=new SBI(); System.out.println("ROI: "+b.rateOfInterest()); }}
  108. 108. Multiple inheritance in Java by interface 108
  109. 109. 109 interface Printable{ void print(); } interface Showable{ void show(); } class A7 implements Printable,Showable { public void print(){System.out.println("Hello");} public void show(){System.out.println("Welcome");} public static void main(String args[]){ A7 obj = new A7(); obj.print(); obj.show(); } }
  110. 110. Assignment-11 (Interfaces) 1. Write a program to demonstrate interface. • Interface A int a, int b m1() m2() • Class B  Implements methods from A and calculate sum of a and b 2. Write a program for multiple inheritance by using interface. • Interface A int a, int b m1() m2() • Interface B  int a, int b m3() m4() • Class A  Implements methods from A and B interfaces. 110
  111. 111. Java Packages • A java package is a group of similar types of classes, interfaces and sub-packages. • Package in java can be categorized in two form, built-in package and user-defined package. • There are many built-in packages such as java, lang, awt, javax, swing, net, io, util, sql etc. 111
  112. 112. Access package from another package • There are three ways to access the package from outside the package. • import package.*; • import package.classname; • fully qualified name. 112
  113. 113. Access Modifiers in java • The access modifiers in java specifies accessibility (scope) of a data member, method, constructor or class. • There are 4 types of java access modifiers: • private • default • protected • public 113
  114. 114. private access modifier • The private access modifier is accessible only within class. class A{ private int data=40; private void msg(){System.out.println("Hello java");} } public class Simple{ public static void main(String args[]){ A obj=new A(); System.out.println(obj.data);//Compile Time Error obj.msg();//Compile Time Error } } 114
  115. 115. default access modifier • If you don't use any modifier, it is treated as default by default. The default modifier is accessible only within package. 115 //save by A.java package pack; class A{ void msg(){System.out.println("Hello");} } //save by B.java package mypack; import pack.*; class B{ public static void main(String args[]){ A obj = new A();//Compile Time Error obj.msg();//Compile Time Error } } * In the above example, the scope of class A and its method msg() is default so it cannot be accessed from outside the package.
  116. 116. protected access modifier • The protected access modifier is accessible within package and outside the package but through inheritance only. • The protected access modifier can be applied on the data member, method and constructor. It can't be applied on the class. 116
  117. 117. 117 //save by A.java package pack; public class A { protected void msg() { System.out.println("Hello"); } } //save by B.java package mypack; import pack.*; class B extends A { public static void main(String args[] ) { B obj = new B(); obj.msg(); } }
  118. 118. public access modifier • The public access modifier is accessible everywhere. It has the widest scope among all other modifiers. 118 //save by A.java package pack; public class A{ public void msg() {System.out.println("Hello"); } } //save by B.java package mypack; import pack.*; class B{ public static void main(String args[]) { A obj = new A(); obj.msg(); } }
  119. 119. All java access modifiers 119 Access Modifier within class within package outside package by subclass only outside package Private Y N N N Default Y Y N N Protected Y Y Y N Public Y Y Y Y
  120. 120. Java Exceptions • Exception is an abnormal condition. • In java, exception is an event that disrupts the normal flow of the program. • There are two types of exceptions. 1. Checked Exceptions 2. Un-checked Exceptions 120
  121. 121. Un Checked Exceptions • Exceptions that are NOT checked by compiler are called Un-Checked Exceptions. • Un checked Exceptions successfully compiled by Java compiler. • At run time it throws exception. • Examples: • ArithmeticException • NullPointerException • NumberFormatException • ArrayIndexOutOfBoundsException 121
  122. 122. Common Un-Checked exceptions • ArithmeticException • If we divide any number by zero, there occurs an ArithmeticException. int a=50/0; //ArithmeticException • NullPointerException • If we have null value in any variable, performing any operation by the variable occurs an NullPointerException. String s=null; System.out.println(s.length()); //NullPointerException 122
  123. 123. • NumberFormatException • The wrong formatting of any value, may occur NumberFormatException. Suppose I have a string variable that have characters, converting this variable into digit will occur NumberFormatException. String s="abc"; int i=Integer.parseInt(s);//NumberFormatException 123
  124. 124. • ArrayIndexOutOfBoundsException • If you are inserting any value in the wrong index, it would result ArrayIndexOutOfBoundsException as shown below: int a[]=new int[5]; a[10]=50; //ArrayIndexOutOfBoundsException 124
  125. 125. Checked Exceptions • Exceptions that are checked by compiler are called Checked Exceptions. • If a program contains checked-Exception code is not compiled. • Examples: • InterruptedException • IOException • FileNotFoundException etc. 125
  126. 126. Common Checked exceptions • InterruptedException Thread.sleep(3000); //Throws InterruptedException • FileNotFoundException & IOException FileReader fr = new FileReader("C:Test.txt"); //FileNotException BufferedReader bfr = new BufferedReader(fr); System.out.println(bfr.readLine()); //IOException 126
  127. 127. Java Exception Handling Keywords • try • catch • finally • throws 127
  128. 128. Java try..catch block • Java try block is used to enclose the code that might throw an exception. • It must be applied at statement level within the method. • Java try block must be followed by either catch or finally block. • Used for both Un-checked and Checked Exceptions. • Syntax of java try-catch try{ //code that may throw exception }catch(Exception_class_Name ref){} • Syntax of try-finally block try{ //code that may throw exception }finally{} 128
  129. 129. Java catch block • Java catch block is used to handle the Exception. It must be used after the try block only. • You can use multiple catch block with a single try. 129
  130. 130. Problem without exception handling • Output: Exception in thread main java.lang.ArithmeticException:/ by zero 130 public class Testtrycatch1{ public static void main(String args[]) { int data=50/0; //may throw exception System.out.println("rest of the code..."); } }
  131. 131. Solution by exception handling Output: Exception in thread main java.lang.ArithmeticException:/ by zero rest of the code... 131 public class Testtrycatch2{ public static void main(String args[]){ try{ int data=50/0; }catch(ArithmeticException e){System.out.println(e);} System.out.println("rest of the code..."); } }
  132. 132. Internal working of java try-catch block 132
  133. 133. Java Multi catch block • If you have to perform different tasks at the occurrence of different Exceptions, use java multi catch block. 133 Output:task1 completed rest of the code... public class TestMultipleCatchBlock{ public static void main(String args[]){ try{ int a[]=new int[5]; a[5]=30/0; } catch(ArithmeticException e){System.out.println("task1 is completed");} catch(ArrayIndexOutOfBoundsException e){System.out.println("task 2 completed");} catch(Exception e){System.out.println("common task completed");} System.out.println("rest of the code..."); } }
  134. 134. Java finally block • Java finally block is a block that is used to execute important code such as closing connection, stream etc. • Java finally block is always executed whether exception is handled or not. • Java finally block follows try or catch block. 134
  135. 135. 135
  136. 136. Usage of Java finally • Cases 1. Exception doesn't occur. 2. Exception occurs and not handled. 3. Exception occurs and handled. 136
  137. 137. Case 1: Java finally example where exception doesn't occur 137 Output:5 finally block is always executed rest of the code... class TestFinallyBlock{ public static void main(String args[]){ try{ int data=25/5; System.out.println(data); } catch(NullPointerException e){System.out.println(e);} finally{System.out.println("finally block is always exec uted");} System.out.println("rest of the code..."); } }
  138. 138. Case 2: Java finally example where exception occurs and not handled. 138 Output:finally block is always executed Exception in thread main java.lang.ArithmeticException:/ by zero class TestFinallyBlock1{ public static void main(String args[]){ try{ int data=25/0; System.out.println(data); } catch(NullPointerException e){System.out.println(e);} finally{System.out.println("finally block is always executed");} System.out.println("rest of the code..."); } }
  139. 139. Case 3: Java finally example where exception occurs and handled. 139 Output:Exception in thread main java.lang.ArithmeticException:/ by zero finally block is always executed rest of the code... public class TestFinallyBlock2{ public static void main(String args[]){ try{ int data=25/0; System.out.println(data); } catch(ArithmeticException e){System.out.println(e);} finally{System.out.println("finally block is always executed");} System.out.println("rest of the code..."); } }
  140. 140. throws • Used for only Checked Exceptions. • It should be applied at Method level. 140
  141. 141. throws – Example1 141 public class Test { public static void main(String[] args) throws InterruptedException { System.out.println("Test started"); System.out.println("Test is in progress"); Thread.sleep(3000); // InterruptedException System.out.println("Test is completed"); System.out.println("Test is exited"); } }
  142. 142. throws – Example2 142 public class Test { public static void main(String[] args) throws IOException { FileReader fr = new FileReader("C:Test.txt"); //FileNotException BufferedReader bfr = new BufferedReader(fr); System.out.println(bfr.readLine()); //IOException } }
  143. 143. 143 Un-Checked Checked Method Level Within the method Try..Catch Y Y N Y throws N Y Y N
  144. 144. Assignment-12(Exception Handling) 1. Write a java program for the following and handle exceptions by using try..catch and finally blocks. • Any number divide by zero. • int a[]=null; • a.length • String s="abc"; • int i=Integer.parseInt(s); 2. Write a java program to handle IO Exception by using throws. 144
  145. 145. ArrayList • ArrayList is pre defined class in Java used for dynamic array for storing elements. • ArrayList can contains duplicate elements. • We can add, insert and remove elements from ArrayList. • Syntax: • ArrayList al=new ArrayList();//allows all data types • ArrayList<String> al=new ArrayList<String>();//Allows only String data types 145
  146. 146. Java ArrayList Example 146 import java.util.*; class TestCollection1{ public static void main(String args[]){ ArrayList<String> list=new ArrayList<String>();//Creating arraylist list.add("Ravi");//Adding object in arraylist list.add("Vijay"); list.add("Ravi"); list.add("Ajay"); //Traversing list through Iterator Iterator itr=list.iterator(); while(itr.hasNext()){ System.out.println(itr.next()); } } }
  147. 147. Iterating Array List through for-each loop 147 import java.util.*; class TestCollection2{ public static void main(String args[]){ ArrayList<String> al=new ArrayList<String>(); al.add("Ravi"); al.add("Vijay"); al.add("Ravi"); al.add("Ajay"); for(String obj:al) System.out.println(obj); } }
  148. 148. ArrayList Methods 148 import java.util.*; public class ArrayListDemo { public static void main(String args[]) { // create an array list ArrayList al = new ArrayList(); System.out.println("Initial size of al: " + al.size()); // add elements to the array list al.add("C"); al.add("A"); al.add("E"); al.add("B"); al.add("D"); al.add("F"); al.add(1, "A2"); System.out.println("Size of al after additions: " + al.size()); // display the array list System.out.println("Contents of al: " + al); // Remove elements from the array list al.remove("F"); al.remove(2); System.out.println("Size of al after deletions: " + al.size()); System.out.println("Contents of al: " + al); } }
  149. 149. Assignment-13(ArrayList) 1. Define an array list and store some values and read them using for…each loop. 2. Define an array list with 5 elements and Search an element present or not in the arraylist. 3. Define a string array list with 5 integers and print them in reverse order. 149
  150. 150. HashMap • The important points about Java HashMap class are: • A HashMap contains values based on the key. • It contains only unique elements. • It may have one null key and multiple null values. • It maintains no order. 150
  151. 151. Java HashMap Example 151 Output:102 Rahul 100 Amit 101 Vijay import java.util.*; class TestCollection13{ public static void main(String args[]){ HashMap<Integer,String> hm=new HashMap<Integer,String>(); hm.put(100,"Amit"); hm.put(101,"Vijay"); hm.put(102,"Rahul"); for(Map.Entry m:hm.entrySet()){ System.out.println(m.getKey()+" "+m.getValue()); } } }
  152. 152. Java HashMap Example: remove() 152 Output: Values before remove: {102=Operating System, 103=Data Communication and Networking, 101=Let us C} Values after remove: {103=Data Communication and Networking, 101=Let us C} import java.util.*; public class HashMapExample { public static void main(String args[]) { // create and populate hash map HashMap<Integer, String> map = new HashMap<Integer, String>(); map.put(101,"Let us C"); map.put(102, "Operating System"); map.put(103, "Data Communication and Networking"); System.out.println("Values before remove: "+ map); // Remove value for key 102 map.remove(102); System.out.println("Values after remove: "+ map); } }
  153. 153. Assignment-14 (HashMap) • Create a HashMap and do the following. • Add the following keys(EMPID’s) and their values(ENAME’s) to the HashMap • EMPID ENAME • 101 DAVID • 102 SCOTT • 103 JOHN • Read and print all the keys and their values using for each loop. • Remove a pair from HashMap • 101 DAVID • Print the keysets in HashMap. 153
  154. 154. JDBC – Java Database Connectivity • Java JDBC is a java API to connect and execute query with the database. • JDBC API uses jdbc drivers to connect with the database. 154
  155. 155. 5 Steps to connect to the database in java 1. Register the driver class 2. Creating connection 3. Creating statement 4. Executing queries 5. Closing connection 155
  156. 156. • Example to register the OracleDriver class Class.forName("oracle.jdbc.driver.OracleDriver"); • Create the connection object Connection con=DriverManager.getConnection( "jdbc:oracle:thin:@localhost:1521:xe","system","password"); • Create the Statement object Statement stmt=con.createStatement(); • Execute the query ResultSet rs=stmt.executeQuery("select * from emp"); while(rs.next()){ System.out.println(rs.getInt(1)+" "+rs.getString(2)); } • Close the connection object con.close(); 156
  157. 157. Select data from database table 157 import java.sql.*; public class DBConnection { public static void main(String[] args) throws SQLException, ClassNotFoundException { // 1 - Register the OracleDriver class Class.forName("oracle.jdbc.driver.OracleDriver"); // 2-Create the connection object Connection con = DriverManager.getConnection("jdbc:oracle:thin:@INVRLX61ILM40:1521:ORA11G", “scott",“tiger"); // 3 - Create the Statement object Statement stmt = con.createStatement(); // 4-Execute the query ResultSet rs = stmt.executeQuery("select * from employee order by EMPLOYEE_ID"); while (rs.next()) { System.out.print(rs.getString("first_name")); System.out.println(" " + rs.getInt("salary")); } // 5- close connection objects rs.close(); con.close(); } }
  158. 158. Database Operations • Insert • Update • Delete • Select 158
  159. 159. Insert data into database table 159 import java.sql.*; public class DBConnection { public static void main(String[] args) throws SQLException, ClassNotFoundException { // 1 - Register the OracleDriver class Class.forName("oracle.jdbc.driver.OracleDriver"); // 2-Create the connection object Connection con = DriverManager.getConnection("jdbc:oracle:thin:@INVRLX61ILM40:1521:ORA11G", “scott",“tiger"); // 3 - Create the Statement object Statement stmt = con.createStatement(); // 4-Execute the query stmt.executeQuery("insert into employee(EMPLOYEE_ID,LAST_NAME,FIRST_NAME) values(1234,'ABC','XYX')"); // 5- close connection objects rs.close(); con.close(); } }
  160. 160. Update data in database table 160 import java.sql.*; public class DBConnection { public static void main(String[] args) throws SQLException, ClassNotFoundException { // 1 - Register the OracleDriver class Class.forName("oracle.jdbc.driver.OracleDriver"); // 2-Create the connection object Connection con = DriverManager.getConnection("jdbc:oracle:thin:@INVRLX61ILM40:1521:ORA11G", “scott",“tiger"); // 3 - Create the Statement object Statement stmt = con.createStatement(); // 4-Execute the query stmt.executeQuery("update employee set FIRST_NAME='abc' WHERE EMPLOYEE_ID=7778"); // 5- close connection objects rs.close(); con.close(); } }
  161. 161. Delete data from database table 161 import java.sql.*; public class DBConnection { public static void main(String[] args) throws SQLException, ClassNotFoundException { // 1 - Register the OracleDriver class Class.forName("oracle.jdbc.driver.OracleDriver"); // 2-Create the connection object Connection con = DriverManager.getConnection("jdbc:oracle:thin:@INVRLX61ILM40:1521:ORA11G", “scott",“tiger"); // 3 - Create the Statement object Statement stmt = con.createStatement(); // 4-Execute the query stmt.executeQuery("delete from employee where EMPLOYEE_ID=1234"); // 5- close connection objects rs.close(); con.close(); } }
  162. 162. Assignment-15(JDBC) • Connect to database and check how many number of records present in the Employee table. • Connect to database and display all the employees details where employees belongs to deptno 10. • Connect oracle database and Display employee details whose is earning highest salary. 162

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