Deflater与Inflater的压缩与解压缩

Posted 2020-06-12

package util;

import java.util.Arrays;
import java.util.zip.Deflater;
import java.util.zip.Inflater;

import org.apache.commons.codec.binary.Base64;


public class StringZlibUtil {

	/**
	 * 用zlib压缩
	 * @param message
	 * @return
	 * @throws Exception
	 */
	public static byte[] zlibCompress(String message)throws Exception
	{
		String chatacter="UTF-8";
		byte[] input = message.getBytes(chatacter);
		System.out.println("input length "+input.length);
	    byte[] output = new byte[input.length+10+new Double(Math.ceil(input.length*0.25f)).intValue()];
	    System.out.println(output.length);
	    Deflater compresser = new Deflater();
	    compresser.setInput(input);
	    compresser.finish();
	    int compressedDataLength = compresser.deflate(output);
	    System.out.println("compressedDataLength "+compressedDataLength);
	    compresser.end();	    
	    //String ostr=new String(output,0,compressedDataLength,chatacter);
	    //System.out.println("out str "+ostr);
	    return Arrays.copyOf(output, compressedDataLength);
	}
	/**
	 * 解压缩
	 * @param barr   须要解压缩的字节数组
	 * @param charater  相应压缩时的编码方式
	 * @return
	 * @throws Exception
	 */
	public static byte[] zlibInfCompress(byte[] barr,String charater)throws Exception{
		byte[] result=new byte[2014];
		Inflater inf=new Inflater();
		inf.setInput(barr);
		int infLen=inf.inflate(result);
		inf.end();
		String strOgr=new String(result,charater);
		System.out.println("str ogr "+strOgr);
		return Arrays.copyOf(result, infLen);
	}
	public static void main(String[] args)throws Exception{
		
		String str="abcde|qqqqqqqqqqqqqqq|wwwwwwwwwwwwwwwwwwww";
		//方法一：
		/*byte[] def=StringZlibUtil.zlibCompress(str);
		byte[] inf=StringZlibUtil.zlibInfCompress(def, "UTF-8");
		String strOgr=new String(inf,"UTF-8");
		System.out.println("str org main "+strOgr);*/
		
		//方法二：下面是使用基本base64的编码与解码
		byte[] def=StringZlibUtil.zlibCompress(str);
		String strBase=Base64.encodeBase64String(def);
		System.out.println("str base64 string "+strBase);
		byte[] decStr=Base64.decodeBase64(strBase);
		byte[] decode_str=StringZlibUtil.zlibInfCompress(decStr, "UTF-8");
		String decStrOgr=new String(decode_str,"UTF-8");
		System.out.println("decStrOgr "+decStrOgr);
	}
}