关于java解压缩文件（rar或者zip）的实现示例

注意：需要用到第三方jar包ant-1.6.5.jar，实际用到的是其中的zip下类。

代码如下：

import java.io.File;  import java.io.FileInputStream;  import java.io.FileOutputStream;  import java.io.IOException;  import java.io.InputStream;  import java.util.Enumeration;  import org.apache.tools.zip.ZipEntry;  import org.apache.tools.zip.ZipFile;  import org.apache.tools.zip.ZipOutputStream;    /**   * <p>   * Title: 解压缩文件   * </p>   * <p>   * Description: 通过apache的zip工具实现解压缩   * </p>   * <p>   * Copyright: Copyright (c) 2010   * </p>   * <p>   * Company: yourcompany   * </p>   *    * @author yourcompany   * @version 1.0   */  public class CompressFile {   private static CompressFile instance = new CompressFile();     private CompressFile() {   }     public static CompressFile getInstance() {    return instance;   }     /**    * 压缩文件或者文件目录到指定的zip或者rar包    *     * @param inputFilename    *            要压缩的文件或者文件夹，如果是文件夹的话，会将文件夹下的所有文件包含子文件夹的内容进行压缩    * @param zipFilename    *            生成的zip或者rar文件的名称    */   public synchronized void zip(String inputFilename, String zipFilename)     throws IOException {    zip(new File(inputFilename), zipFilename);   }     /**    * 压缩文件或者文件目录到指定的zip或者rar包，内部调用    *     * @param inputFile    *            参数为文件类型的要压缩的文件或者文件夹    * @param zipFilename    *            生成的zip或者rar文件的名称    * @return void    */   private synchronized void zip(File inputFile, String zipFilename)     throws IOException {    ZipOutputStream out = new ZipOutputStream(new FileOutputStream(      zipFilename));      try {     zip(inputFile, out, "");    } catch (IOException e) {     throw e;    } finally {     out.close();    }   }     /**    * 压缩文件或者文件目录到指定的zip或者rar包    *     * @param inputFile    *            参数为文件类型的要压缩的文件或者文件夹    * @param out    *            输出流    * @param base    *            基文件夹    * @return void    */   private synchronized void zip(File inputFile, ZipOutputStream out,     String base) throws IOException {    if (inputFile.isDirectory()) {     File[] inputFiles = inputFile.listFiles();     out.putNextEntry(new ZipEntry(base + "/"));     base = base.length() == 0 ? "" : base + "/";     for (int i = 0; i < inputFiles.length; i++) {      zip(inputFiles[i], out, base + inputFiles[i].getName());     }      } else {     if (base.length() > 0) {      out.putNextEntry(new ZipEntry(base));     } else {      out.putNextEntry(new ZipEntry(inputFile.getName()));     }       FileInputStream in = new FileInputStream(inputFile);     try {      int c;      byte[] by = new byte[BUFFEREDSIZE];      while ((c = in.read(by)) != -1) {       out.write(by, 0, c);      }     } catch (IOException e) {      throw e;     } finally {      in.close();     }    }   }     /**    * 解压zip或者rar包的内容到指定的目录下，可以处理其文件夹下包含子文件夹的情况    *     * @param zipFilename    *            要解压的zip或者rar包文件    * @param outputDirectory    *            解压后存放的目录    */   public synchronized void unzip(String zipFilename, String outputDirectory)     throws IOException {    File outFile = new File(outputDirectory);    if (!outFile.exists()) {     outFile.mkdirs();    }      ZipFile zipFile = new ZipFile(zipFilename);    Enumeration en = zipFile.getEntries();    ZipEntry zipEntry = null;    while (en.hasMoreElements()) {     zipEntry = (ZipEntry) en.nextElement();     if (zipEntry.isDirectory()) {      // mkdir directory      String dirName = zipEntry.getName();      // System.out.println("=dirName is:=" + dirName + "=end=");      dirName = dirName.substring(0, dirName.length() - 1);      File f = new File(outFile.getPath() + File.separator + dirName);      f.mkdirs();     } else {      // unzip file      String strFilePath = outFile.getPath() + File.separator        + zipEntry.getName();      File f = new File(strFilePath);        // the codes remedified by can_do on 2010-07-02 =begin=      // /////begin/////      // 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);       // 此处使用.mkdirs()方法，而不能用.mkdir()       tempDir.mkdirs();      }      // /////end///      // the codes remedified by can_do on 2010-07-02 =end=      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 {       out.close();       in.close();      }     }    }   }     private static final int BUFFEREDSIZE = 1024;     public static void main(String[] args) {    CompressFile bean = new CompressFile();    try {     boolean isZip = false;     if (isZip) {      bean.zip("E:\\20100707", "d:/test_rar.zip");     } else {      bean.unzip("d:/test_rar.zip", "D:/temp");     }    } catch (IOException e) {     e.printStackTrace();    }   }    }