content: package com.taobao.atlas.update.util;
  
  import java.io.Closeable;
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.Enumeration;
  import java.util.zip.ZipEntry;
  import java.util.zip.ZipFile;
  
  /**
   * Created by wuzhong on 2016/11/23.
   */
  
  public class ZipUtils {
  
      private static int BUFFEREDSIZE = 1024;
  
      public static void unzip(String zipFilename, String outputDirectory)
              throws IOException {
          File outFile = new File(outputDirectory);
          if (!outFile.exists()) {
              outFile.mkdirs();
          }
          if (!outFile.exists()) {
              throw new IOException("file not exist");
          }
          ZipFile zipFile = new ZipFile(zipFilename);
          Enumeration en = zipFile.entries();
          ZipEntry zipEntry = null;
          while (en.hasMoreElements()) {
              zipEntry = (ZipEntry) en.nextElement();
              if (zipEntry.isDirectory()) {
                  String dirName = zipEntry.getName();
                  dirName = dirName.substring(0, dirName.length() - 1);
                  File f = new File(outFile.getPath() + File.separator + dirName);
                  f.mkdirs();
              } else {
                  String strFilePath = outFile.getPath() + File.separator
                          + zipEntry.getName();
                  File f = new File(strFilePath);
  
                  // 判断文件不存在的话，就创建该文件所在文件夹的目录
                  if (!f.exists()) {
                      String[] arrFolderName = zipEntry.getName().split("/");
                      String strRealFolder = "";
                      for (int i = 0; i < (arrFolderName.length - 1); i++) {
                          strRealFolder += arrFolderName[i] + File.separator;
                      }
                      strRealFolder = outFile.getPath() + File.separator
                              + strRealFolder;
                      File tempDir = new File(strRealFolder);
                      tempDir.mkdirs();
                  }
                  f.createNewFile();
                  InputStream in = zipFile.getInputStream(zipEntry);
                  FileOutputStream out = new FileOutputStream(f);
                  try {
                      int c;
                      byte[] by = new byte[BUFFEREDSIZE];
                      while ((c = in.read(by)) != -1) {
                          out.write(by, 0, c);
                      }
                      out.flush();
                  } catch (IOException e) {
                      throw e;
                  } finally {
                      closeQuitely(out);
                      closeQuitely(in);
                  }
              }
          }
          zipFile.close();
      }
  
      private static void closeQuitely(Closeable stream) {
          try {
              if (stream != null)
                  stream.close();
          } catch (IOException e) {
              e.printStackTrace();
          }
      }
  
  }
  