java实现zip与unzip

jdk提供了Zip相关的类方便的实现压缩和解压缩。使用方法很简单。下边分别是压缩和解压缩的简单事例
1，压缩的

import java.io.BufferedInputStream;  
import java.io.BufferedOutputStream;  
import java.io.File;  
import java.io.FileInputStream;  
import java.io.FileOutputStream;  
import java.util.zip.ZipEntry;  
import java.util.zip.ZipOutputStream;  
public class Zip {  
  static final int BUFFER = 2048;  
  public static void main(String argv[]) {  
    try {  
      BufferedInputStream origin = null;  
      FileOutputStream dest = new FileOutputStream("E:\\test\\myfiles.zip");  
      ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(dest));  
      byte data[] = new byte[BUFFER];  
      File f = new File("e:\\test\\a\\");  
      File files[] = f.listFiles();  
      for (int i = 0; i < files.length; i++) {  
        FileInputStream fi = new FileInputStream(files[i]);  
        origin = new BufferedInputStream(fi, BUFFER);  
        ZipEntry entry = new ZipEntry(files[i].getName());  
        out.putNextEntry(entry);  
        int count;  
        while ((count = origin.read(data, 0, BUFFER)) != -1) {  
          out.write(data, 0, count);  
        }  
        origin.close();  
      }  
      out.close();  
    } catch (Exception e) {  
      e.printStackTrace();  
    }  
  }  
}

2，解压缩的。

import java.io.BufferedInputStream;  
import java.io.BufferedOutputStream;  
import java.io.File;  
import java.io.FileOutputStream;  
import java.util.Enumeration;  
import java.util.zip.ZipEntry;  
import java.util.zip.ZipFile;  
public class UnZip {  
  static final int BUFFER = 2048;  
  public static void main(String argv[]) {  
    try {  
      String fileName = "E:\\test\\myfiles.zip";  
      String filePath = "E:\\test\\";  
      ZipFile zipFile = new ZipFile(fileName);  
      Enumeration emu = zipFile.entries();  
      int i = 0;  
      while (emu.hasMoreElements()) {  
        ZipEntry entry = (ZipEntry) emu.nextElement();  
        // 会把目录作为一个file读出一次，所以只建立目录就可以，之下的文件还会被迭代到。  
        if (entry.isDirectory()) {  
          new File(filePath + entry.getName()).mkdirs();  
          continue;  
        }  
        BufferedInputStream bis = new BufferedInputStream(zipFile.getInputStream(entry));  
        File file = new File(filePath + entry.getName());  
        // 加入这个的原因是zipfile读取文件是随机读取的，这就造成可能先读取一个文件  
        // 而这个文件所在的目录还没有出现过，所以要建出目录来。  
        File parent = file.getParentFile();  
        if (parent != null && (!parent.exists())) {  
          parent.mkdirs();  
        }  
        FileOutputStream fos = new FileOutputStream(file);  
        BufferedOutputStream bos = new BufferedOutputStream(fos, BUFFER);  
        int count;  
        byte data[] = new byte[BUFFER];  
        while ((count = bis.read(data, 0, BUFFER)) != -1) {  
          bos.write(data, 0, count);  
        }  
        bos.flush();  
        bos.close();  
        bis.close();  
      }  
      zipFile.close();  
    } catch (Exception e) {  
      e.printStackTrace();  
    }  
  }  
}