压缩字节

package test;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.zip.Deflater;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.InflaterOutputStream;

import org.xerial.snappy.Snappy;


import net.jpountz.lz4.LZ4BlockOutputStream;
import net.jpountz.lz4.LZ4Compressor;
import net.jpountz.lz4.LZ4Factory;


public class TestZip {
	  static ByteBuffer buffer=ByteBuffer.allocate(20);
	  public static long bytesToLong(byte[] bytes) { 
	
	        buffer.put(bytes, 0, bytes.length);    
	        buffer.flip();//need flip     
	        return buffer.getLong();    
	    }  
	  public static byte[] longToBytes(long x) {    
	        buffer.putLong(0, x);    
	        return buffer.array();    
	    } 
	public static void main(String[] args) throws UnsupportedEncodingException {
      String str="snowolf@zlex.org;dongliang@zlex.org;zlex.dongliang@zl";
       String str1="adsfsaasdfsnowolf@zlex.org;dongliang@zlex.org;zlex.dongliang@zl";
       System.out.println(str);
       byte [] aa=str.getBytes("UTF-8");
       byte [] aa1=str1.getBytes("UTF-8");
       System.out.println(aa.length);
	   byte [] bb=lengthCp(aa);
	   byte [] bb1=lengthCp(aa1);
	   byte[] data3 = new byte[bb.length + bb1.length]; 
	   //System.arraycopy(aa,0,data3,0,aa.length);
      // System.arraycopy(aa1,0,data3,aa.length,aa1.length);
	  // System.arraycopy(bb,0,data3,0,bb.length);
	   System.arraycopy(bb1,0,data3,0,bb1.length);
	   System.out.println(bb.length);
	   System.out.println(data3.length);
	   lengthDp(data3);
	   
	}

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(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[] datas ){
/*	byte[] datas =Arrays.copyOfRange(data, 4, data.length);
	byte[] dat = Arrays.copyOfRange(data, 0, 4);*/
	try {
		
/*	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();
	
	ByteBuffer temp = ByteBuffer
			.allocate(baos.toByteArray().length);// 解压数据长度
	temp.put(baos.toByteArray());
	System.out.println(new String(temp.array()));
	} catch (Exception e) {
		e.printStackTrace();
	}
}	

public static byte[] lz4Compress(byte[] data) throws IOException {
    LZ4Factory factory = LZ4Factory.fastestInstance();
    ByteArrayOutputStream byteOutput = new ByteArrayOutputStream();
    LZ4Compressor compressor = factory.fastCompressor();
    LZ4BlockOutputStream compressedOutput = new LZ4BlockOutputStream(byteOutput, 8192, compressor);
    compressedOutput.write(data);
    compressedOutput.close();
    return byteOutput.toByteArray();
}

//snappy 压缩
public static byte[] snappyCompress(byte[] data) throws IOException {
    return Snappy.compress(data);
}
 
public static byte[] snappyDecompress(byte[] data) throws IOException {
    return Snappy.uncompress(data);
}
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)  
    };  
} 
private void compressBillNo(byte[] buf, String s) {
	int b1, b2;
	for (int i = 0; i < 6; i++) {
		b1 = s.charAt(i * 2) - 48;//48即为'0'
		b2 = s.charAt(i * 2 + 1) - 48;
		buf[i] = (byte) ((b1 << 4) | b2);
	}
}
}