Example of Charset in Java NIO

By Arvind Rai, December 13, 2013

java.nio.charset.Charset has been introduced in JDK 1.4. Charset plays the role of encoding and decoding between given charset and UNICODE. Charset name should follow some rule. It must begin with a letter or number. Charset has the canonical name as an alias and java supports it. Charset methods are safe to use in multithreading environment.

Standard charsets

The supported Charset in java are given below.
US-ASCII: Seven bit ASCII characters.
ISO-8859-1: ISO Latin alphabet
UTF-8: This is 8 bit UCS transformation format.
UTF-16BE: This is 16 bit UCS transformation format with big endian byte order
UTF-16LE: This is 16 bit UCS transformation with little endian byte order.
UTF-16: 16 bit UCS transformation format.

Charset.forName() in Java NIO

Creates a charset object for the given charset name. The name can be canonical or an alias.

Charset.displayName() in Java NIO

This method returns canonical name of charset.

Charset.canEncode() in Java NIO

This method checks whether the given charset supports encoding or not.

Charset.decode() in Java NIO

This method decodes the string of a given charset into charbuffer of Unicode charset.

Charset.encode() in Java NIO

This method encodes charbuffer of unicode charset into the byte buffer of given charset.
CharsetExample.java

package com.concretepage.nio.charset;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
public class CharsetExample {
	public static void main(String[] args) {
		 Charset charset=Charset.forName("US-ASCII");
		 System.out.println(charset.displayName());
		 System.out.println(charset.canEncode());
		 String s= "Hello, This is Charset Example.";
		 //convert byte buffer in given charset to char buffer in unicode
		 ByteBuffer bb = ByteBuffer.wrap(s.getBytes());
		 CharBuffer cb = charset.decode(bb);
		//convert char buffer in unicode to byte buffer in given charset
		 ByteBuffer newbb = charset.encode(cb);
		 while(newbb.hasRemaining()){
	        	char ch = (char) newbb.get();
	        	System.out.print(ch);
	     }
		 newbb.clear();
	}
}

In the example, we have taken a charset canonical name as US-ASCII and we are changing a string into char buffer of Unicode charset by using byte buffer with US-ASCII charset and again changing that char buffer of Unicode charset into byte buffer of given charset.

Output

US-ASCII
Hello, This is Charset Example.

POSTED BY

ARVIND RAI

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