content: package com.github.misterchangray.common.utils;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.RandomAccessFile;
  import java.nio.ByteBuffer;
  import java.nio.channels.FileChannel;
  import java.util.zip.GZIPInputStream;
  import java.util.zip.GZIPOutputStream;
  import java.util.zip.ZipEntry;
  import java.util.zip.ZipFile;
  /**
   * @author tanml
   * 将一串数据按照gzip方式压缩和解压缩
   */
  public class GZipUtils {
      // 压缩
      public static byte[] compress(byte[] data) throws IOException {
          if (data == null || data.length == 0) {
              return null;
          }
          ByteArrayOutputStream out = new ByteArrayOutputStream();
          GZIPOutputStream gzip = new GZIPOutputStream(out);
          gzip.write(data);
          gzip.close();
          return out.toByteArray();//out.toString("ISO-8859-1");
      }
  
      public static byte[] compress(String str) throws IOException {
          if (str == null || str.length() == 0) {
              return null;
          }
          return compress(str.getBytes("utf-8"));
      }
  
      // 解压缩
      public static byte[] uncompress(byte[] data) throws IOException {
          if (data == null || data.length == 0) {
              return data;
          }
          ByteArrayOutputStream out = new ByteArrayOutputStream();
          ByteArrayInputStream in = new ByteArrayInputStream(data);
          GZIPInputStream gunzip = new GZIPInputStream(in);
          byte[] buffer = new byte[256];
          int n;
          while ((n = gunzip.read(buffer)) >= 0) {
              out.write(buffer, 0, n);
          }
          gunzip.close();
          in.close();
          return out.toByteArray();
      }
  
      public static String uncompress(String str) throws IOException {
          if (str == null || str.length() == 0) {
              return str;
          }
          byte[] data = uncompress(str.getBytes("utf-8")); // ISO-8859-1
          return new String(data);
      }
  
      /**
       * @param @param  unZipfile
       * @param @param  destFile 指定读取文件，需要从压缩文件中读取文件内容的文件名
       * @param @return 设定文件
       * @return String 返回类型
       * @throws
       * @Title: unZip
       * @Description: TODO(这里用一句话描述这个方法的作用)
       */
      public static String unZip(String unZipfile, String destFile) {// unZipfileName需要解压的zip文件名
          InputStream inputStream;
          String inData = null;
          try {
              // 生成一个zip的文件
              File f = new File(unZipfile);
              ZipFile zipFile = new ZipFile(f);
  
              // 遍历zipFile中所有的实体，并把他们解压出来
              ZipEntry entry = zipFile.getEntry(destFile);
              if (!entry.isDirectory()) {
                  // 获取出该压缩实体的输入流
                  inputStream = zipFile.getInputStream(entry);
  
                  ByteArrayOutputStream out = new ByteArrayOutputStream();
                  byte[] bys = new byte[4096];
                  for (int p = -1; (p = inputStream.read(bys)) != -1; ) {
                      out.write(bys, 0, p);
                  }
                  inData = out.toString();
                  out.close();
                  inputStream.close();
              }
              zipFile.close();
          } catch (IOException ioe) {
              ioe.printStackTrace();
          }
          return inData;
      }
  
      public static void main(String[] args) {
          String json = "{\"androidSdk\":22,\"androidVer\":\"5.1\",\"cpTime\":1612071603,\"cupABIs\":[\"armeabi-v7a\",\"armeabi\"],\"customId\":\"QT99999\",\"elfFlag\":false,\"id\":\"4a1b644858d83a98\",\"imsi\":\"460015984967892\",\"system\":true,\"systemUser\":true,\"test\":true,\"model\":\"Micromax R610\",\"netType\":0,\"oldVersion\":\"0\",\"pkg\":\"com.adups.fota.sysoper\",\"poll_time\":30,\"time\":1481634113876,\"timeZone\":\"Asia\\/Shanghai\",\"versions\":[{\"type\":\"gatherApks\",\"version\":1},{\"type\":\"kernel\",\"version\":9},{\"type\":\"shell\",\"version\":10},{\"type\":\"silent\",\"version\":4},{\"type\":\"jarUpdate\",\"version\":1},{\"type\":\"serverIps\",\"version\":1}]}";
          json = "ksjdflkjsdflskjdflsdfkjsdf";
          try {
              byte[] buf = GZipUtils.compress(json);
  
              File fin = new File("D:/temp/test4.txt");
              FileChannel fcout = new RandomAccessFile(fin, "rws").getChannel();
              ByteBuffer wBuffer = ByteBuffer.allocateDirect(buf.length);
              fcout.write(wBuffer.wrap(buf), fcout.size());
              if (fcout != null) {
                  fcout.close();
              }
          } catch (IOException e) {
              // TODO Auto-generated catch block
              e.printStackTrace();
          }
      }
  }
  