Study Anytime Any Where We Will Open The Knowledge For You Anish Sir 24x7 Learning solution It Is Time to join JOB
25 May 2018

Study Anytime Any Where

25 May 2018

We Will Open The Knowledge For You

25 May 2018

Anish Sir 24x7 Learning solution

25 May 2018

It Is Time to join JOB

C Programming

C++ Programming

JAVA Programming

Android Language

Android-logo.png

.Net Programming

net-logo-b55c217213ae49991589ed43d7ed58a7.png

c# Programming

photo_1389636992_quiz_image_temp.png

Asp .Net

asplogo-square.png

PHP Programming

58481791cef1014c0b5e4994.png

Search Your Topic

config
Anish Sir

Anish Sir

"I am delighted once again to pen the welcome note to the Tosh!Yas Technologies ."

 Call +91 74 88 34 7779  | Email : anishsingh@live.com

Website URL: http://toshiyas.in
Monday, 28 August 2017 09:49

I'm good at

Again, 'I'm' is used here as 'I am.' 'Good at' informs someone what you excel at and are comfortable doing.

Here are some examples:

"I'm good at drawing."("मैं ड्राइंग में अच्छा हूँ")

"I'm good at video games."("मैं वीडियो गेम में अच्छा हूँ।")
"I'm good at swimming."("मैं तैराकी में अच्छा हूँ।")
"I'm good at driving."("मैं ड्राइविंग में अच्छा कर रहा हूँ।")
"I'm good at reading."("मैं पढ़ने में अच्छा कर रहा हूँ।")
"I'm good at sports."("मैं खेल में अच्छा हूँ।")
"I'm good at writing."("मैं लिखने में अच्छा हूँ।")
"I'm good at math."("मैं गणित में अच्छा कर रहा हूँ।")
"I'm good at dancing."("मैं नृत्य करने में अच्छा हूँ।")
"I'm good at chess."("मैं शतरंज में अच्छा हूं।")

Monday, 28 August 2017 09:46

I'm in/at/on

Most commonly, you would use the word 'in' when entering a physical location such as a room or a building.

Here are some examples:

"I'm in the shower."("मैं शॉवर में हूं।")

"I'm in the lobby."("मैं आंगन में हूँ।")
"I'm in a car."("मैं एक कार में हूं।")
"I'm in a house."("मैं एक घर में हूं।")
"I'm in a school."("मैं एक स्कूल में हूँ।")

Using the word 'at' helps tell someone where you currently are. The difference between 'at' and 'in' is that the physical location is general.

Here are some examples:

"I'm at the grocery."("मैं किराने की दुकान पर हूं।")

"I'm at the mall."("मैं मॉल में हूँ।")

"I'm at the doctor's office."("मैं डॉक्टर के कार्यालय में हूं।")
"I'm at the park."("मैं पार्क में हूँ।")
"I'm at the airport."("मैं हवाई अड्डे पर हूं।")


However, in some cases you can use 'at' and 'in' interchangeably.

Here are some examples:

"I'm at the mall."("मैं मॉल में हूँ।")

"I'm in the mall."("मैं मॉल में हूँ।")
"I'm at the park."("मैं पार्क में हूँ।")
"I'm in the park."("मैं पार्क में हूँ।")
"I'm at the grocery."("मैं किराने की दुकान पर हूं।")
"I'm in the grocery."("मैं किराने में हूं।")

Using the word 'on' is referring to a non physical location such as your time being utilized by something else.

Here are some examples:

"I'm on the phone."("मै फ़ोन पर हूँ।")

"I'm on my computer."("मैं अपने कंप्यूटर पर हूं।")
"I'm on a bus."("मैं बस में हूँ।")

Monday, 28 August 2017 07:29

I'm

'I'm' is an abbreviation for the word 'I AM.' It is used in combination with other words to tell someone about yourself or to describe something you are doing.

Here are some examples:

"I'm so tired."("मैं बहुत थक गया हूँ।")
"I'm confused."("मैं उलझन में हूं।")
"I'm happy."("में खुश हूँ।")

"I'm twenty three years old."(मैं तेईस साल का हूँ। ")
"I'm hungry."("मुझे भूख लगी है।")

"I'm nervous."("मैं घबरा रहा हूँ।")

"I'm excited."("में उत्साहित हु।")

"I'm leaving work."("मैं काम छोड़ रहा हूं।")

"I'm thirsty."("मैं प्यासा हूँ।")
"I'm from Seattle."("मैं सीएटल से हूँ।")


You can also add descriptive words with 'I'm' such as:

"I'm extremely tired."("मैं बहुत थका हुआ हूँ।")
"I'm very happy."("मैं बहुत खुश हूँ।")
"I'm terribly hungry."("मै बहुत जय़ादा भूखा हूॅ।")

"I am super excited."("मैं बहुत उत्साहित हूँ।")

"I'm very nervous."("मैं बहुत घबराया हुआ हूँ।")

Monday, 28 August 2017 06:56

English Speaking

Tuesday, 08 August 2017 04:35

Java Interview Questions

Q) What is polymorphism ?

Ans) The ability to define a function in multiple forms is called Polymorphism. In java, c++ there are two types of polymorphism: compile time polymorphism (overloading) and runtime polymorphism (overriding).

Method overriding: happens when a child class implements the method with same signature as a method in a parent class. When you override methods, JVM determines the proper methods to call at the program’s runtime, not at the compile time.

Method overloading: happens when several methods have same names but different number or type of parameters. Overloading is determined at the compile time.

  • Overloading happens when:
  • Different method signature and different number or type of parameters.
  • Same method signature but different number of parameters.
  • Same method signature and same number of parameters but of different type
Example of Overloading
int add(int a,int b)
 float add(float a,int b)
 float add(int a ,float b)
 void add(float a)
 int add(int a)
 void add(int a) //error conflict with the  method int add(int a)
class BookDetails {
  String title;
  setBook(String title){}
}
class ScienceBook extends BookDetails {
  setBook(String title){} //overriding
  setBook(String title, String publisher,float price){} //overloading
}
 

Q) What is use of serialVersionUID?

Ans) The default Java serialization mechanism writes the metadata about the object, which includes the class name, field names and types, and superclass. This class definition is stored as a part of the serialized object. This stored metadata enables the deserialization process to reconstitute the objects and map the stream data into the class attributes with the appropriate type
Everytime an object is serialized the java serialization mechanism automatically computes a hash value. ObjectStreamClass's computeSerialVersionUID() method passes the class name, sorted member names, modifiers, and interfaces to the secure hash algorithm (SHA), which returns a hash value.The serialVersionUID is also called suid.
So when the serilaize object is retrieved , the JVM first evaluates the suid of the serialized class and compares the suid value with the one of the object. If the suid values match then the object is said to be compatible with the class and hence it is de-serialized. If not InvalidClassException exception is thrown.

Changes to a serializable class can be compatible or incompatible. Following is the list of changes which are compatible:

  • Add fields
  • Change a field from static to non-static
  • Change a field from transient to non-transient
  • Add classes to the object tree

List of incompatible changes:

  • Delete fields
  • Change class hierarchy
  • Change non-static to static
  • Change non-transient to transient
  • Change type of a primitive field

So, if no suid is present, inspite of making compatible changes, jvm generates new suid thus resulting in an exception if prior release version object is used .

The only way to get rid of the exception is to recompile and deploy the application again.

If we explicitly mention the suid using the statement:
private final static long serialVersionUID = <integer value>

then if any of the metioned compatible changes are made the class need not to be recompiled. But for incompatible changes there is no other way than to compile again.

Q) What is the difference between final, finally and finalize() in Java?

Ans) final - A final variable acts as a constant, a final class is immutable and a final method cannot be override in a child class.

finally - finally keyword is used with try-catch block for handling exception. The finally block is optional in try-catch block. The finally code block is always executed after try or catch block is completed. The general use case for finally block is to close the resources or clean up objects used in try block. For e.g. Closing a FileStream, I/O stream objects, Database connections, HTTP connections are generally closed in a finally block.

finalize() - This is the method of Object class.It is invoked before an object is discarded by the garbage collector, allowing it to clean up its state. Should not be used to release non-memory resources like file handles, sockets, database connections etc because Java has only a finite number of these resources and you do not know when the garbage collection is going to kick in to release these non-memory resources through the finalize() method.

Q4)What is difference between HashMap and HashTable?

Ans) Both collections implements Map. Both collections store value as key-value pairs. The key differences between the two are:

  1. Hashmap is not synchronized in nature but hashtable is(thread-safe). This means that in a multithreaded application, only one thread can gets access to a hashtable object and do an operation on it. Hashmap doesn't gurantee such behavior and is not used in multithreaded environment.
  2. Hashmap is traveresed using an iterator, hashtable can be traversed by enumerator or iterator.
  3. Iterator in hashmap is fail-fast, enumerator in hashtable is not fail-fast
  4. HashMap permits null values and only one null key, while Hashtable doesn't allow key or value as null.
  5. Since hashtable is synchornized, it is relatively slower in performance than hashmap

Q) What is difference between abstract class and interface ?

Ans) A class is called abstract when it is declared with keywordabstract. Abstract class contains atleast one abstract method. It can also contain n numbers of concrete method. Interface can only contain abstract methods.

  • Interface can have only abstract methods. Abstract class can have concerete and abstract methods.
  • The abstract class can have public, private, protected or default variables and also constants. In interface the variable is by default public final. In nutshell the interface doesnt have any variables it only has constants.
  • A class can extend only one abstract class but a class can implement multiple interfaces. Abstract class doesn't support multiple inheritance whereas abstract class does.
  • If an interface is implemented its mandatory to implement all of its methods but if an abstract class is extended its mandatory to implement all abstract methods.
  • The problem with an interface is, if you want to add a new feature (method) in its contract, then you MUST implement those method in all of the classes which implement that interface. However, in the case of an abstract class, the method can be simply implemented in the abstract class and the same can be called by its subclass.

 

Q) What is the difference between equals() and == ?

Ans) == operator is used to compare the references of the objects. 
public bollean equals(Object o) is the method provided by the Object class. The default implementation uses == operator to compare two objects. But since the method can be overriden like for String class. equals() method can be used to compare the values of two objects.

String str1 = "MyName"; 
String str2 = "MyName";
String str3 = new String(str2);

if (str1 == str2) {
  System.out.println("Objects are equal")
}else{
  System.out.println("Objects are not equal")
}
if(str1.equals(str2)) {
  System.out.println("Objects are equal")
} else {
  System.out.println("Objects are not equal")
}

Output:
Objects are not equal
Objects are equal
String str2 = "MyName";
String str3 = str2;
if (str2 == str3) {
System.out.println("Objects are equal")
}else{
System.out.println("Objects are not equal")
}
if (str3.equals(str2)) {
  System.out.println("Objects are equal")
} else {
  System.out.println("Objects are not equal")
}

Output:
Objects are equal
Objects are equal

Q) What is difference between a thread and a process?

Ans)

  • Threads share the address space of the process that created it; process has it's own address space.
  • Threads have direct access to the data segment of its process; processes have their own copy of the data segment of the parent process.
  • Threads can directly communicate with other threads of its process; processes must use interprocess communication to communicate with sibling processes.
  • Threads have almost no overhead; processes have considerable overhead.
  • New threads are easily created; new processes require duplication of the parent process.
  • Threads can exercise considerable control over threads of the same process; processes can only exercise control over child processes.
  • Changes to the main thread (cancellation, priority change etc.) may affect the behavior of the other threads of the process; changes to the parent process do not affect child processes.

Q) What is use of synchronized keyword?

Ans) synchronized keyword can be applied to static/non-static methods or a block of code. Only one thread at a time can access synchronized methods and if there are multiple threads trying to access the same method then other threads have to wait for the execution of method by one thread. Synchronized keyword provides a lock on the object and thus prevents race condition. E.g.

public void synchronized method(){} 
  public void synchronized staticmethod(){}
  public void myMethod(){
     synchronized (this){ 
        //synchronized keyword on block of code
     }
  }

Q)Is garbage collector a dameon thread?

Ans) Yes GC is a dameon thread. A dameon thread runs behind the application. It is started by JVM. The thread stops when all non-dameon threads stop.

Q)How is Garbage Collection managed?

Ans)The JVM controls the Garbage Collector; it decides when to run the Garbage Collector. JVM runs the Garbage Collector when it realizes that the memory is running low. The behavior of GC can be tuned by passing parameters to JVM. One can request the Garbage Collection to happen from within the java program but there is no guarantee that this request will be taken care of by jvm.

Saturday, 05 August 2017 08:10

Java JButton

The JButton class is used to create a labeled button that has platform independent implementation. The application result in some action when the button is pushed. It inherits AbstractButton class.

JButton class declaration

Let's see the declaration for javax.swing.JButton class.

 
  1. public class JButton extends AbstractButton implements Accessible  

Commonly used Constructors:

Constructor Description
JButton() It creates a button with no text and icon.
JButton(String s) It creates a button with the specified text.
JButton(Icon i) It creates a button with the specified icon object.

Commonly used Methods of AbstractButton class:

Methods Description
void setText(String s) It is used to set specified text on button
String getText() It is used to return the text of the button.
void setEnabled(boolean b) It is used to enable or disable the button.
void setIcon(Icon b) It is used to set the specified Icon on the button.
Icon getIcon() It is used to get the Icon of the button.
void setMnemonic(int a) It is used to set the mnemonic on the button.
void addActionListener(ActionListener a) It is used to add the action listener to this object.

Java JButton Example

 
  1. import javax.swing.*;    
  2. public class ButtonExample {  
  3. public static void main(String[] args) {  
  4.     JFrame f=new JFrame("Button Example");  
  5.     JButton b=new JButton("Click Here");  
  6.     b.setBounds(50,100,95,30);  
  7.     f.add(b);  
  8.     f.setSize(400,400);  
  9.     f.setLayout(null);  
  10.     f.setVisible(true);   
  11. }  
  12. }  

Output:

JAVA Jbutton 1


Java JButton Example with ActionListener

 
  1. import java.awt.event.*;  
  2. import javax.swing.*;    
  3. public class ButtonExample {  
  4. public static void main(String[] args) {  
  5.     JFrame f=new JFrame("Button Example");  
  6.     final JTextField tf=new JTextField();  
  7.     tf.setBounds(50,50150,20);  
  8.     JButton b=new JButton("Click Here");  
  9.     b.setBounds(50,100,95,30);  
  10.     b.addActionListener(new ActionListener(){  
  11. public void actionPerformed(ActionEvent e){  
  12.             tf.setText("Welcome to Javatpoint.");  
  13.         }  
  14.     });  
  15.     f.add(b);f.add(tf);  
  16.     f.setSize(400,400);  
  17.     f.setLayout(null);  
  18.     f.setVisible(true);   
  19. }  
  20. }  

Output:

JAVA Jbutton 2


Example of displaying image on the button:

 
  1. import javax.swing.*;      
  2. public class ButtonExample{    
  3. ButtonExample(){    
  4. JFrame f=new JFrame("Button Example");            
  5. JButton b=new JButton(new ImageIcon("D:\\icon.png"));    
  6. b.setBounds(100,100,10040);    
  7. f.add(b);    
  8. f.setSize(300,400);    
  9. f.setLayout(null);    
  10. f.setVisible(true);    
  11. f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    
  12.     }         
  13. public static void main(String[] args) {    
  14.     new ButtonExample();    
  15. }    
  16. }    

Output:

JAVA Jbutton 3

Saturday, 05 August 2017 08:04

Java Swing

Java Swing tutorial is a part of Java Foundation Classes (JFC) that is used to create window-based applications. It is built on the top of AWT (Abstract Windowing Toolkit) API and entirely written in java.

Unlike AWT, Java Swing provides platform-independent and lightweight components.

The javax.swing package provides classes for java swing API such as JButton, JTextField, JTextArea, JRadioButton, JCheckbox, JMenu, JColorChooser etc.


Difference between AWT and Swing

There are many differences between java awt and swing that are given below.

No. Java AWT Java Swing
1) AWT components are platform-dependent. Java swing components are platform-independent.
2) AWT components are heavyweight. Swing components are lightweight.
3) AWT doesn't support pluggable look and feel. Swing supports pluggable look and feel.
4) AWT provides less components than Swing. Swing provides more powerful components such as tables, lists, scrollpanes, colorchooser, tabbedpane etc.
5) AWT doesn't follows MVC(Model View Controller) where model represents data, view represents presentation and controller acts as an interface between model and view. Swing follows MVC.

What is JFC

The Java Foundation Classes (JFC) are a set of GUI components which simplify the development of desktop applications.

Hierarchy of Java Swing classes

The hierarchy of java swing API is given below.

hierarchy of javax swing


Commonly used Methods of Component class

The methods of Component class are widely used in java swing that are given below.

Method Description
public void add(Component c) add a component on another component.
public void setSize(int width,int height) sets size of the component.
public void setLayout(LayoutManager m) sets the layout manager for the component.
public void setVisible(boolean b) sets the visibility of the component. It is by default false.

Java Swing Examples

There are two ways to create a frame:

  • By creating the object of Frame class (association)
  • By extending Frame class (inheritance)

We can write the code of swing inside the main(), constructor or any other method.


Simple Java Swing Example

Let's see a simple swing example where we are creating one button and adding it on the JFrame object inside the main() method.

File: FirstSwingExample.java

 
  1. import javax.swing.*;  
  2. public class FirstSwingExample {  
  3. public static void main(String[] args) {  
  4. JFrame f=new JFrame();//creating instance of JFrame  
  5.           
  6. JButton b=new JButton("click");//creating instance of JButton  
  7. b.setBounds(130,100,10040);//x axis, y axis, width, height  
  8.           
  9. f.add(b);//adding button in JFrame  
  10.           
  11. f.setSize(400,500);//400 width and 500 height  
  12. f.setLayout(null);//using no layout managers  
  13. f.setVisible(true);//making the frame visible  
  14. }  
  15. }  

simple example of java swing


Example of Swing by Association inside constructor

We can also write all the codes of creating JFrame, JButton and method call inside the java constructor.

File: Simple.java

 
  1. import javax.swing.*;  
  2. public class Simple {  
  3. JFrame f;  
  4. Simple(){  
  5. f=new JFrame();//creating instance of JFrame  
  6.           
  7. JButton b=new JButton("click");//creating instance of JButton  
  8. b.setBounds(130,100,10040);  
  9.           
  10. f.add(b);//adding button in JFrame  
  11.           
  12. f.setSize(400,500);//400 width and 500 height  
  13. f.setLayout(null);//using no layout managers  
  14. f.setVisible(true);//making the frame visible  
  15. }  
  16.   
  17. public static void main(String[] args) {  
  18. new Simple();  
  19. }  
  20. }  

The setBounds(int xaxis, int yaxis, int width, int height)is used in the above example that sets the position of the button.


Simple example of Swing by inheritance

We can also inherit the JFrame class, so there is no need to create the instance of JFrame class explicitly.

File: Simple2.java

 
  1. import javax.swing.*;  
  2. public class Simple2 extends JFrame{//inheriting JFrame  
  3. JFrame f;  
  4. Simple2(){  
  5. JButton b=new JButton("click");//create button  
  6. b.setBounds(130,100,10040);  
  7.           
  8. add(b);//adding button on frame  
  9. setSize(400,500);  
  10. setLayout(null);  
  11. setVisible(true);  
  12. }  
  13. public static void main(String[] args) {  
  14. new Simple2();  
  15. }}  
What we will learn in Swing Tutorial
  • JButton class
  • JRadioButton class
  • JTextArea class
  • JComboBox class
  • JTable class
  • JColorChooser class
  • JProgressBar class
  • JSlider class
  • Digital Watch
  • Graphics in swing
  • Displaying image
  • Edit menu code for Notepad
  • OpenDialog Box
  • Notepad
  • Puzzle Game
  • Pic Puzzle Game
  • Tic Tac Toe Game
  • BorderLayout
  • GridLayout
  • FlowLayout
  • CardLayout
Tuesday, 01 August 2017 06:18

Java AWT Label

The object of Label class is a component for placing text in a container. It is used to display a single line of read only text. The text can be changed by an application but a user cannot edit it directly.

AWT Label Class Declaration

 
  1. public class Label extends Component implements Accessible  

Java Label Example

 
  1. import java.awt.*;  
  2. class LabelExample{  
  3. public static void main(String args[]){  
  4.     Frame f= new Frame("Label Example");  
  5.     Label l1,l2;  
  6.     l1=new Label("First Label.");  
  7.     l1.setBounds(50,100100,30);  
  8.     l2=new Label("Second Label.");  
  9.     l2.setBounds(50,150100,30);  
  10.     f.add(l1); f.add(l2);  
  11.     f.setSize(400,400);  
  12.     f.setLayout(null);  
  13.     f.setVisible(true);  
  14. }  
  15. }  

Output:

java awt label example 1

Java AWT Label Example with ActionListener

 
  1. import java.awt.*;  
  2. import java.awt.event.*;  
  3. public class LabelExample extends Frame implements ActionListener{  
  4.     TextField tf; Label l; Button b;  
  5.     LabelExample(){  
  6.         tf=new TextField();  
  7.         tf.setBounds(50,50150,20);  
  8.         l=new Label();  
  9.         l.setBounds(50,100250,20);      
  10.         b=new Button("Find IP");  
  11.         b.setBounds(50,150,60,30);  
  12.         b.addActionListener(this);    
  13.         add(b);add(tf);add(l);    
  14.         setSize(400,400);  
  15.         setLayout(null);  
  16.         setVisible(true);  
  17.     }  
  18.     public void actionPerformed(ActionEvent e) {  
  19.         try{  
  20.         String host=tf.getText();  
  21.         String ip=java.net.InetAddress.getByName(host).getHostAddress();  
  22.         l.setText("IP of "+host+" is: "+ip);  
  23.         }catch(Exception ex){System.out.println(ex);}  
  24.     }  
  25.     public static void main(String[] args) {  
  26.         new LabelExample();  
  27.     }  
  28. }  

Output:

TextField: www.toshiyas.in

IP Of www.toshiyas.in is 144.18.16.18

Button : Find IP

 

Tuesday, 01 August 2017 06:09

Java AWT Button

The button class is used to create a labeled button that has platform independent implementation. The application result in some action when the button is pushed.

AWT Button Class declaration

 
  1. public class Button extends Component implements Accessible  

Java AWT Button Example

 
  1. import java.awt.*;  
  2. public class ButtonExample {  
  3. public static void main(String[] args) {  
  4.     Frame f=new Frame("Button Example");  
  5.     Button b=new Button("Click Here");  
  6.     b.setBounds(50,100,80,30);  
  7.     f.add(b);  
  8.     f.setSize(400,400);  
  9.     f.setLayout(null);  
  10.     f.setVisible(true);   
  11. }  
  12. }  

Output:

java awt button example 1

Java AWT Button Example with ActionListener

 
  1. import java.awt.*;  
  2. import java.awt.event.*;  
  3. public class ButtonExample {  
  4. public static void main(String[] args) {  
  5.     Frame f=new Frame("Button Example");  
  6.     final TextField tf=new TextField();  
  7.     tf.setBounds(50,50150,20);  
  8.     Button b=new Button("Click Here");  
  9.     b.setBounds(50,100,60,30);  
  10.     b.addActionListener(new ActionListener(){  
  11.     public void actionPerformed(ActionEvent e){  
  12.             tf.setText("Welcome to Toshiyas IT");  
  13.         }  
  14.     });  
  15.     f.add(b);f.add(tf);  
  16.     f.setSize(400,400);  
  17.     f.setLayout(null);  
  18.     f.setVisible(true);   
  19. }  
  20. }  

Output:

welcome to Toshiyas IT

Click Here

Page 7 of 33