[java][nio]用Buffer操纵数据

import java.nio.ByteBuffer;
import java.nio.CharBuffer;

public class UsingBuffers {

	private static void symmetricScramble(CharBuffer buffer){
		//若有介于position和limit之间的元素，则返回true
		while(buffer.hasRemaining()){
			buffer.mark();
			char c1 = buffer.get();
			char c2 = buffer.get();
			buffer.reset();//把position设为mark的值
			buffer.put(c2).put(c1);
		}
	}
	
	public static void main(String[] args) {
		char[] data = "UsingBuffers".toCharArray();
		ByteBuffer bb = ByteBuffer.allocate(data.length * 2);
		CharBuffer cb = bb.asCharBuffer();
		cb.put(data);
		System.out.println(cb.rewind());//把position的值设为起始位置
		symmetricScramble(cb);
		System.out.println(cb.rewind());
		symmetricScramble(cb);
		System.out.println(cb.rewind());
	}
	/*
	 
	 UsingBuffers
	 sUniBgfuefsr
	 UsingBuffers
	 
	 */

}