When will you use Serializable or Externalizable Interface? and why

Most of the times when you want to do a selective attribute serialization you can use Serializable interface with transient modifier for variables not to be serialized. However, use of Externalizable interface can be really effective in cases when you have to serialize only some dynamically selected attributes of a large object. Lets take an … Read more

What is the Difference Between Externalizable and Serializable Interfaces?

This is one of top serialization questions that is asked in many big companies to test your in-depth understanding of serialization. Serializable is a marker interface therefore you are not forced to implement any methods, however Externalizable contains two methods readExternal() and writeExternal() which must be implemented. Serializable interface provides a inbuilt serialization mechanism to … Read more

Why is Serialization Required? What is the Need to Serialize

Serialization is required for a variety of reasons. It is required to send across the state of an object over a network by means of a socket. One can also store an object’s state in a file. Additionally, manipulation of the state of an object as streams of bytes is required. The core of Java … Read more

Define Serialization? What do you mean by Serialization in Java

Serialization is a mechanism by which you can save or transfer the state of an object by converting it to a byte stream. This can be done in java by implementing Serialiazable interface. Serializable is defined as a marker interface which needs to be implemented for transferring an object over a network or persistence of … Read more

How to Add A Jar File To Java System Classpath At Run-Time

This can be done by using a simple reflection API hack as demonstrated in below sample code. This example assumes you have a file “c:/Sample.txt” that is not already in class path and at run-time c:/ is added the System classpath and then Sample.txt is made available. import java.io.File; import java.io.InputStream; import java.lang.reflect.Method; import java.net.URL; import java.net.URLClassLoader;   public class HackJavaClasspath {   … Read more