解压和字节整数转换

package test;

import java.io.ByteArrayOutputStream;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.InflaterOutputStream;


public class TestZip {

	public static void main(String[] args) throws UnsupportedEncodingException {
       String str="snowolf@zlex.org;dongliang@zlex.org;zlex.dongliang@zl";
       System.out.println(str);
       byte [] aa=str.getBytes("UTF-8");
       System.out.println(aa.length);
	   byte [] bb=lengthCp(aa);
	   System.out.println(bb.length);
	   lengthDp(bb);
	   
	}

public static byte[] lengthCp(byte[] datas){
	try {
	ByteBuffer buffer = ByteBuffer.allocate(datas.length);
	buffer.put(datas);
	ByteArrayOutputStream baos = new ByteArrayOutputStream();
	DeflaterOutputStream dos = new DeflaterOutputStream(baos);
	dos.write(buffer.array());
	dos.finish();
	
	int len = buffer.array().length;
	ByteBuffer temp = ByteBuffer
			.allocate(4+baos.toByteArray().length);// 压缩前的数据长度
	temp.put(intToByteArray(len));//长度校验
	temp.put(baos.toByteArray());
	return temp.array();
	} catch (Exception e) {
		e.printStackTrace();
	}
	return new byte[0];
}
public static void lengthDp(byte[] data ){
	byte[] datas = new byte[data.length-4];
	byte[] dat = new byte[4];
	try {
		System.arraycopy(data,0,dat,0,4);
		System.arraycopy(data,4,datas,0,data.length-4);
		
	int a=byteArrayToInt(dat); 
	System.out.println(a);	
	ByteBuffer buffer = ByteBuffer.allocate(datas.length);
	buffer.put(datas);
	ByteArrayOutputStream baos = new ByteArrayOutputStream();
	InflaterOutputStream dos = new InflaterOutputStream(baos);
	dos.write(buffer.array());
	dos.finish();
	
	int len = buffer.array().length;
	ByteBuffer temp = ByteBuffer
			.allocate(baos.toByteArray().length);// 压缩前的数据长度
	temp.put(baos.toByteArray());
	System.out.println(new String(temp.array()));
	} catch (Exception e) {
		e.printStackTrace();
	}
}	

public static int byteArrayToInt(byte[] b) {  
    return   b[3] & 0xFF |  
            (b[2] & 0xFF) << 8 |  
            (b[1] & 0xFF) << 16 |  
            (b[0] & 0xFF) << 24;  
}  
  
public static byte[] intToByteArray(int a) {  
    return new byte[] {  
        (byte) ((a >> 24) & 0xFF),  
        (byte) ((a >> 16) & 0xFF),     
        (byte) ((a >> 8) & 0xFF),     
        (byte) (a & 0xFF)  
    };  
} 
}