java实现zlib压缩解压缩：文件、byte[]字节数组，数据流

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全栈工程师开发手册（作者：栾鹏）

java教程全解

java实现zlib压缩解压缩。
有关ZLib可参见官方主页 http://www.zlib.net/
ZLib可以简单的理解为压缩/解压缩算法，它与ZIP、RAR等归档算法有所不同，与bzip2比较接近。

测试代码

public static void main(String[] args)     {        //测试字节数组        System.err.println("字节压缩／解压缩测试");          String inputStr = "snowolf@zlex.org;dongliang@zlex.org;zlex.dongliang@zlex.org";          System.err.println("输入字符串:\t" + inputStr);          byte[] input = inputStr.getBytes();          System.err.println("输入字节长度:\t" + input.length);          byte[] data = ZLibUtils.compress(input);          System.err.println("压缩后字节长度:\t" + data.length);          byte[] output = ZLibUtils.decompress(data);          System.err.println("解压缩后字节长度:\t" + output.length);          String outputStr = new String(output);          System.err.println("输出字符串:\t" + outputStr);          //测试文件        String filename = "zlib";          File file = new File(filename);          System.err.println("文件压缩／解压缩测试");            try {              FileOutputStream fos = new FileOutputStream(file);              ZLibUtils.compress(input, fos);              fos.close();              System.err.println("压缩后字节长度:\t" + file.length());          } catch (Exception e) {              System.err.println("错误:\t" + e.getMessage());          }          try {              FileInputStream fis = new FileInputStream(file);              output = ZLibUtils.decompress(fis);              fis.close();          } catch (Exception e) {              System.err.println("错误:\t" + e.getMessage());          }          System.err.println("解压缩后字节长度:\t" + output.length);          outputStr = new String(output);          System.err.println("输出字符串:\t" + outputStr);      }

zlib压缩解压缩工具类的实现

package com.lp.app.io;import java.io.ByteArrayOutputStream;  import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;  import java.io.InputStream;  import java.io.OutputStream;  import java.util.zip.Deflater;  import java.util.zip.DeflaterOutputStream;  import java.util.zip.Inflater;  import java.util.zip.InflaterInputStream;  //ZLib压缩工具 public class ZLibUtils {      //压缩直接数组     public static byte[] compress(byte[] data) {          byte[] output = new byte[0];          Deflater compresser = new Deflater();          compresser.reset();          compresser.setInput(data);          compresser.finish();          ByteArrayOutputStream bos = new ByteArrayOutputStream(data.length);          try {              byte[] buf = new byte[1024];              while (!compresser.finished()) {                  int i = compresser.deflate(buf);                  bos.write(buf, 0, i);              }              output = bos.toByteArray();          } catch (Exception e) {              output = data;              e.printStackTrace();          } finally {              try {                  bos.close();              } catch (IOException e) {                  e.printStackTrace();              }          }          compresser.end();          return output;      }      //压缩 字节数组到输出流    public static void compress(byte[] data, OutputStream os) {          DeflaterOutputStream dos = new DeflaterOutputStream(os);          try {              dos.write(data, 0, data.length);              dos.finish();              dos.flush();          } catch (IOException e) {              e.printStackTrace();          }      }      //解压缩 字节数组    public static byte[] decompress(byte[] data) {          byte[] output = new byte[0];          Inflater decompresser = new Inflater();          decompresser.reset();          decompresser.setInput(data);          ByteArrayOutputStream o = new ByteArrayOutputStream(data.length);          try {              byte[] buf = new byte[1024];              while (!decompresser.finished()) {                  int i = decompresser.inflate(buf);                  o.write(buf, 0, i);              }              output = o.toByteArray();          } catch (Exception e) {              output = data;              e.printStackTrace();          } finally {              try {                  o.close();              } catch (IOException e) {                  e.printStackTrace();              }          }          decompresser.end();          return output;      }      //解压缩 输入流 到字节数组    public static byte[] decompress(InputStream is) {          InflaterInputStream iis = new InflaterInputStream(is);          ByteArrayOutputStream o = new ByteArrayOutputStream(1024);          try {              int i = 1024;              byte[] buf = new byte[i];              while ((i = iis.read(buf, 0, i)) > 0) {                  o.write(buf, 0, i);              }          } catch (IOException e) {              e.printStackTrace();          }          return o.toByteArray();      }  }

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