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Top Most Important Multithreading interview question and answers

1) What is Thread in java? Threads consumes CPU in best possible manner, hence enables multi processing. Multi threading reduces idle time of CPU which improves performance of application. Thread are light weight process. It belongs to java.lang package. It can run mutiple threads simutaneously .                                                               2) How to implements threads in java?         By   implementing java.lang.Runnable interface or extending java.lang.Thread class and then extending run method.   Thread creation by implementing java.lang.Runnable interface.      And then create Thread object by calling constructor and passing reference of Runnable interface i.e. runnable object          Thread thread = new Thread(runnable); 3) We should implement Runnable interface or extend Thread class. What are differences between implementing Runnable and extending Thread?                 you must extend Thread only when you are look
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MYSQL Interview question..

MySQL is an open source relational database management system RDBMS based on Structured Query Language SQL MySQL runs on virtually all platforms, including Linux, Unix, Windows. Although it can be used in a wide range of applications, MySQL is most often associated with web-based applications and online publishing and is an important component of an open source enterprise. 1) What is SQL? SQL stands for Structured Query Language. SQL was initially developed at IBM in 1970s. SQL is the standard language to communicate with relational database management systems like Oracle, MS Access, MS SQL Server, MySQL, DB2 etc. It is used to connect the objects with the database . 2)what is the Purpose of SQL? • SQL is used to Create New Databases. • SQL is used to Create New Tables in a Database. • SQL is used to Insert, update, Delete records in a Database. • SQL is used to Retrieve data from a Database. • SQL is used to execute queries against a Database. • SQL can set permis
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Top java programs for fresher

1) Write a program to find a repeated word? package com.repeat; import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.util.HashMap; import java.util.Set; public class RepeatedWords { public static void main(String[] args)  { //Creating wordCountMap which holds words as keys and their occurrences as values                  HashMap<String, Integer> wordCountMap = new HashMap<String, Integer>();               BufferedReader reader = null;                   try         {             //Creating BufferedReader object                           reader = new BufferedReader(new FileReader("C:\\sample.txt"));                           //Reading the first line into currentLine                           String currentLine = reader.readLine();                           while (currentLine != null)             {                     //splitting the currentLine
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All difference Question in java(common difference) (Collections)

1)Difference Between Interfaces And Abstract class? All the methods declared in the Interface are Abstract,where as abstract class must have atleast one abstract method and others may be concrete. In abstract class keyword abstract must be used for method, where as in Interface we need not use the keyword for methods. Abstract class must have Sub class, where as Interface can’t have sub classes.  An abstract class can extend only one class, where as an Interface can extend more than one. 2)Difference between Arrays and Vectors?             Because Vectors are dynamically-allocated, they offer a relatively memory-efficient way of handling lists whose size could change drastically. Arrays are fixed in size and it's wastage of memory problem. A Vector might be a good choice for such an arrangement. Moreover, Vectors have some useful member functions that make coding simpler. While in array is the bad choice of the arrangement and the code become more complex. Vecto
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Commonly asked Top 26 Java Interview Questions

1.what is a transient variable? A transient variable is a variable that may not be serialized. If you don't want to serialize any objects then we have to use Transient Keyword. 2. Why do threads block on I/O? Threads block on i/o (that enters the waiting state) so that other threads may execute while the i/o Operation is performed. So your blocked thread of execution blocks only that: the thread of execution. 3. How are Observer and Observable used? Objects that subclass the Observable class maintain a list of observers. When an Observable object is updated it invokes the update() method of each of its observers to notify the observers that it has changed state. The Observer interface is implemented by objects that observe Observable objects(refer 1.4). 4. What is synchronization and why is it important?                      With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Withou
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Decode of the image file from hibernate and struts

Create a java file for the decoding the image Image.java package com.img.action; import java.awt.image.BufferedImage; import java.io.ByteArrayOutputStream; import java.util.ArrayList; import java.util.Iterator; import java.util.LinkedHashMap; import java.util.List; import java.util.Map; import javax.imageio.ImageIO; import javax.servlet.ServletRequest; import javax.servlet.http.HttpServletRequest; import org.apache.struts2.ServletActionContext; import com.img.dao.ConnectionDAO; import com.img.pojo.Film_TablePojo; import com.img.pojo.imagePojo; import com.opensymphony.xwork2.ActionSupport; public class Show extends ActionSupport { List<Object> values = new ArrayList<Object>();  public List<Object> getValues() { return values; } public void setValues(List<Object> values) { this.values = values; } /*HttpServletRequest request;     public void setServletRequest(HttpServletRequest
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