JAVA EE: December 2015

Java Tutorial : Java Class Methods or Static Methods

Click here to watch in Youtube :
https://www.youtube.com/watch?v=q1yPqx3HB4o&list=UUhwKlOVR041tngjerWxVccw

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Java Tutorial : Java Class Methods or Static Methods

ClassMethodTest.java

public class ClassMethodTest
{

    public static void main(String[] args)
    {
        ClassMethodTest.display("Hello");

        ClassMethodTest classMethodTest = new ClassMethodTest();

        /*
         * You can also refer to static methods with an object reference like
         * below. but this is discouraged because it does not make it clear that
         * they are class methods.
         */
        classMethodTest.display("Peter");
    }

    /*
     * Static methods, which have the static modifier in their declarations,
     * should be invoked with the class name, without the need for creating an
     * instance of the class.
     */
    public static void display(String str)
    {
        System.out.println(str);
    }

}

Output

Hello
Peter

Click the below link to download the code:
https://sites.google.com/site/javaee4321/java/ClassMethodDemoApp.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/ClassMethodDemoApp

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/14218d6dfc0ba96c475ae9bea5112ff3ce747d04/BasicJava/ClassMethodDemoApp/?at=master

See also:

Java Tutorial : Java Access modifiers (constructor)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=S_qeZNZiSco&list=UUhwKlOVR041tngjerWxVccw

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Java Tutorial : Java Access modifiers (constructor)

Student.java

package mypack1;

public class Student
{

    public Student()
    {
        System.out.println("Default constructor ...");
    }

}

StudentMyPack1Test.java

package mypack1;

public class StudentMyPack1Test
{

    public static void main(String[] args)
    {
        Student student = new Student();
        System.out.println("student : "+ student);
    }

}

PreKgStudent.java

package mypack2;

import mypack1.Student;

public class PreKgStudent extends Student
{

    public PreKgStudent()
    {
        super();
    }

}

StudentMyPack2Test.java

package mypack2;

import mypack1.Student;

public class StudentMyPack2Test
{

    public static void main(String[] args)
    {
        Student student = new Student();
        System.out.println("student : "+ student);  
    }

}

Click the below link to download the code:
https://sites.google.com/site/javaee4321/java/AccessModifiersDemo-Constructor-App.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/AccessModifiersDemo-Constructor-App/AccessModifiersDemo

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/14218d6dfc0ba96c475ae9bea5112ff3ce747d04/BasicJava/AccessModifiersDemo-Constructor-App/AccessModifiersDemo/?at=master

See also:

Java Tutorial : Java Access modifiers - Playlist

Click here to watch in Youtube :
https://www.youtube.com/watch?v=C_dAFa11kOQ&list=PLmCsXDGbJHdi_wYWFqNhOSfvyZdT3AHyd

See also:

Java Tutorial : Java Access modifiers (method)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=cJMlGffWGpE&list=UUhwKlOVR041tngjerWxVccw

Click the below Image to Enlarge

Java Tutorial : Java Access modifiers (method)

Student.java

package mypack1;

public class Student
{

    void display()
    {
        System.out.println("hello");
    }

}

StudentMyPack1Test.java

package mypack1;

public class StudentMyPack1Test
{

    public static void main(String[] args)
    {
        Student student = new Student();
        student.display();      
    }

}

PreKgStudent.java

package mypack2;

import mypack1.Student;

public class PreKgStudent extends Student
{

    public void displayHello()
    {
        display();
    }

    public static void main(String[] args)
    {
        PreKgStudent preKgStudent = new PreKgStudent();
        preKgStudent.display(); 
    }

}

StudentMyPack2Test.java

package mypack2;

import mypack1.Student;

public class StudentMyPack2Test
{

    public static void main(String[] args)
    {
        Student student = new Student();
        student.display();  
    }

}

Click the below link to download the code:
https://sites.google.com/site/javaee4321/java/AccessModifiersDemo-MethodApp.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/AccessModifiersDemo-MethodApp/AccessModifiersDemo

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/14218d6dfc0ba96c475ae9bea5112ff3ce747d04/BasicJava/AccessModifiersDemo-MethodApp/AccessModifiersDemo/?at=master

See also:

Java Tutorial : Java Access modifiers (field)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=Mji_TGKUNTk&list=UUhwKlOVR041tngjerWxVccw

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Java Tutorial : Java Access modifiers (field)

Student.java

package mypack1;

public class Student
{

    public String name;

}

StudentMyPack1Test.java

package mypack1;

public class StudentMyPack1Test
{

    public static void main(String[] args)
    {
        Student student = new Student();
        System.out.println("name : " + student.name);
    }

}

PreKgStudent.java

package mypack2;

import mypack1.Student;

public class PreKgStudent extends Student
{

    public void displayName()
    {
        System.out.println("name : " + name);
    }

    public static void main(String[] args)
    {
        PreKgStudent preKgStudent = new PreKgStudent();
        System.out.println("name : "+preKgStudent.name);
    }

}

StudentMyPack2Test.java

package mypack2;

import mypack1.Student;

public class StudentMyPack2Test
{

    public static void main(String[] args)
    {
        Student student = new Student();
        System.out.println("name : " + student.name);
    }

}

Click the below link to download the code:
https://sites.google.com/site/javaee4321/java/AccessModifiersDemoFieldApp.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/AccessModifiersDemoFieldApp/AccessModifiersDemo

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/14218d6dfc0ba96c475ae9bea5112ff3ce747d04/BasicJava/AccessModifiersDemoFieldApp/AccessModifiersDemo/?at=master

See also:

Java Tutorial : Java Access modifiers (class)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=C_dAFa11kOQ&list=UUhwKlOVR041tngjerWxVccw

Click the below Image to Enlarge

Java Tutorial : Java Access modifiers (class)

Student.java

package mypack1;

public class Student
{
    private String name;

}

StudentMyPack1Test.java

package mypack1;
public class StudentMyPack1Test
{

    public static void main(String[] args)
    {
        Student student = new Student();
        System.out.println("student : "+student);

    }

}

StudentMyPack2Test.java

package mypack2;

import mypack1.Student;

public class StudentMyPack2Test
{

    public static void main(String[] args)
    {
        Student student = new Student();
        System.out.println("student : " + student);
    }
    
}

Click the below link to download the code:
https://sites.google.com/site/javaee4321/java/AccessModifiersDemoClassApp.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/AccessModifiersDemoClassApp/AccessModifiersDemo

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/14218d6dfc0ba96c475ae9bea5112ff3ce747d04/BasicJava/AccessModifiersDemoClassApp/AccessModifiersDemo/?at=master

See also:

Friday 18 December 2015

Java Tutorial : Java using objects

Click here to watch in Youtube :
https://www.youtube.com/watch?v=jHuygXT2Vig&list=UUhwKlOVR041tngjerWxVccw

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Java Tutorial : Java using objects

Employee.java

public class Employee
{

    String name;
    int age;

    public Employee(String name, int age)
    {
        this.name = name;
        this.age = age;
    }
    
    public int getSalaryInfo()
    {
        return 30000;
    }
    
}

EmployeeTest.java

public class EmployeeTest
{

    public static void main(String[] args)
    {
        Employee johnReferenceVariable = new Employee("John", 25);
        
        System.out.println("name : "+ johnReferenceVariable.name );
        System.out.println("age : "+ johnReferenceVariable.age );
        
        int salary = johnReferenceVariable.getSalaryInfo();
        System.out.println("salary : "+salary);
        
    }

}

Output

name : John
age : 25
salary : 30000

Click the below link to download the code:
https://sites.google.com/site/javaee4321/java/CreateAndUsingObjectDemoApp.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/CreateAndUsingObjectDemoApp

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/f95cef6f929a55d126484d6f51e7b129a718c586/BasicJava/CreateAndUsingObjectDemoApp/?at=master

See also:

Java Tutorial : Java this keyword (pass this to constructor)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=-0Fd6G3Va5o&list=UUhwKlOVR041tngjerWxVccw

Student.java

public class Student
{

    private String name;
    private int age;
    private Address address;

    public Student(String name, int age, Address address)
    {
        this.name = name;
        this.age = age;
        this.address = address;
    }

    public String getName()
    {
        return name;
    }

    public void setName(String name)
    {
        this.name = name;
    }

    public int getAge()
    {
        return age;
    }

    public void setAge(int age)
    {
        this.age = age;
    }

    public Address getAddress()
    {
        return address;
    }

    public void setAddress(Address address)
    {
        this.address = address;
    }

}

Address.java

public class Address
{

    private String country;
    private String city;

    public Address(String country, String city)
    {
        this.country = country;
        this.city = city;
    }

    public String getCountry()
    {
        return country;
    }

    public void setCountry(String country)
    {
        this.country = country;
    }

    public String getCity()
    {
        return city;
    }

    public void setCity(String city)
    {
        this.city = city;
    }

    public Student getStudentWithAddress(String name, int age)
    {
        /*
         * The this keyword can be passed as argument in the constructor call.
         * 
         * It is useful if we have to use one object in multiple classes.
         */
        Student student = new Student(name, age, this);
        return student;
    }
}

StudentTest.java

public class StudentTest
{

    public static void main(String[] args)
    {

        Address addressObject = new Address("India","Bangalore");
        Student student = addressObject.getStudentWithAddress("Peter", 27);
        System.out.println("Name : "+student.getName());
        System.out.println("Age  : "+student.getAge());

        System.out.println("Country : "+student.getAddress().getCountry());
        System.out.println("City    : "+student.getAddress().getCity());
    }

}

Output

Name : Peter
Age  : 27
Country : India
City    : Bangalore

Click the below link to download the code:
https://sites.google.com/site/javaee4321/java/ThisKeyWordDemoPassThisToConsApp.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/ThisKeyWordDemoPassThisToConsApp

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/f95cef6f929a55d126484d6f51e7b129a718c586/BasicJava/ThisKeyWordDemoPassThisToConsApp/?at=master

See also:

Java Tutorial : Java this keyword (return this)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=P6As9evOSvI&list=UUhwKlOVR041tngjerWxVccw

Student.java

public class Student
{

    public String name;
    public int age;

    public Student(String name, int age)
    {
        this.name = name;
        this.age = age;
    }

    /*
     * 
     * We can return the this keyword as an statement from the method. In such
     * case, return type of the method must be the class type (non-primitive).
     */
    public Student getStudent()
    {
        return this;
    }

}

StudentTest.java

public class StudentTest
{

    public static void main(String[] args)
    {

        Student studentObject = new Student("Peter",45);

        System.out.println("studentObject : " + studentObject);

        System.out.println("studentObject : "+studentObject.getStudent());
        
        System.out.println("Name : "+studentObject.getStudent().name);
        System.out.println("Age  : "+studentObject.getStudent().age);

    }

}

Output

studentObject : Student@64a294a6
studentObject : Student@64a294a6
Name : Peter
Age  : 45

Click the below link to download the code:
https://sites.google.com/site/javaee4321/java/ThisKeyWordDemoReturnThisApp.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/ThisKeyWordDemoReturnThisApp

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/f95cef6f929a55d126484d6f51e7b129a718c586/BasicJava/ThisKeyWordDemoReturnThisApp/?at=master

See also:

Thursday 17 December 2015

Java Tutorial : Java this keyword - Playlist

Click here to watch in Youtube :
https://www.youtube.com/watch?v=z-kMDt4mypA&list=PLmCsXDGbJHdj1YwMap_k6Sfs9cngB3aWp

See also:

Java Tutorial : Java this keyword (pass this to method)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=fjHeWySXxPU&list=UUhwKlOVR041tngjerWxVccw

Student.java

public class Student
{

    public String name;
    public int age;

    public Student(String name, int age)
    {
        this.name = name;
        this.age = age;
    }

    public void display()
    {
        /*
         * The this keyword can also be passed as an argument in the method. It
         * is mainly used in the event handling.
         * 
         * In event handling (or) in a situation where we have to provide
         * reference of a class to another one.
         */
        displayFields(this);
    }

    public void displayFields(Student studentObj)
    {
        System.out.println("Name : " + studentObj.name);
        System.out.println("Age  : " + studentObj.age);
    }

}

StudentTest.java

public class StudentTest
{

    public static void main(String[] args)
    {

        Student studentObject = new Student("Peter",35);
        studentObject.display();
    }

}

Output

Name : Peter
Age  : 35

Click the below link to download the code:
https://sites.google.com/site/javaee4321/java/ThisKeyWordDemoPassThistomethodApp.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/ThisKeyWordDemoPassThistomethodApp

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/f95cef6f929a55d126484d6f51e7b129a718c586/BasicJava/ThisKeyWordDemoPassThistomethodApp/?at=master

See also:

Java Tutorial : Java this keyword (print this)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=6PRs713q2Dc&list=UUhwKlOVR041tngjerWxVcc

Student.java

public class Student
{

    private String name;
    private int age;

    public Student(String name, int age)
    {
        this.name = name;
        this.age = age;
    }

    public void printThis()
    {
        System.out.println("this          : " + this);
    }

    public static void main(String[] args)
    {
        Student studentObject = new Student("Peter", 45);
        System.out.println("studentObject : " + studentObject);
        studentObject.printThis();
    }

}

Output

studentObject : Student@48533e64
this          : Student@48533e64

Click the below link to download the code:
https://sites.google.com/site/javaee4321/java/ThisKeyWordDemoPrintApp.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/ThisKeyWordDemoPrintApp

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/f95cef6f929a55d126484d6f51e7b129a718c586/BasicJava/ThisKeyWordDemoPrintApp/?at=master

See also: