学步园

    在Java平台上有很多官方的和非官方、第三方的压缩工具包，它们各有各的长处，比如Oracle官方的java.util.zip 类库，Apache网站上的Apache Commons Compress 类库，或者Chilkat
Java Zip 类库，但总体说来，这些类库提供都是低级别的API，操作起来都不是很方便，而今天推荐给大家的这个叫做ZeroTurnaround(简称zt-zip)的压缩类库的特点就是方便、简易，我们可以比较一下，如果用标准的Java类库压缩一个目录里的所有文件，你需要写出的代码大概是这样：

File dir = new File("demo");
ZipOutputStream out = new ZipOutputStream(new FileOutputStream("demo.zip"));
try {
  File[] files = dir.listFiles();
  for (int i = 0; i < files.length; i++) {
    File file = files[i];
    ZipEntry entry = new ZipEntry(file.getName());
    entry.setSize(file.length());
    entry.setTime(file.lastModified());
    out.putNextEntry(entry);
    FileInputStream in = new FileInputStream(file);
    try {
      IOUtils.copy(in, out);
    }
    finally {
      IOUtils.closeQuietly(in);
    }
    out.closeEntry();
   }
 } finally {
   IOUtils.closeQuietly(out);
}

    而使用 zt-zip 工具包，你的代码就变成了只有一行：

ZipUtil.pack(new File("demo"), new File("demo.zip"));

　　你不需要自己去关闭文件的数据流，这个类库的接口自动替你你做了这些。

　　可能经常做Java压缩编程的人会提到另外一个压缩类库：TrueZIP，这也是一个非常好的类库，而zt-zip跟它比起来的一个优势是：消耗内存很少，这是因为TrueZIP大量的使用了虚拟机的堆内存，而zt-zip却是只是以数据流的形式进行操作，当然这也是zt-zip的API提供的功能很有针对性、不是TrueZIP
API那样通用的原因。

　　你可以在Github上下载这个类库。

Examples

//Unpacking

//Check if an entry exists in a ZIP archive
boolean exists = ZipUtil.containsEntry(new File("/tmp/demo"), "foo.txt");
//Extract an entry from a ZIP archive into a byte array
byte[] bytes = ZipUtil.unpackEntry(new File("/tmp/demo.zip"), "foo.txt");
//Extract an entry from a ZIP archive into file system
ZipUtil.unpackEntry(new File("/tmp/demo.zip"), "foo.txt", new File("/tmp/bar.txt"));
//Extract a ZIP archive
ZipUtil.unpack(new File("/tmp/demo.zip"), new File("/tmp/demo"));
//Extract a ZIP archive which becomes a directory
ZipUtil.explode(new File("/tmp/demo.zip"));
//Extract a directory from a ZIP archive including the directory name
ZipUtil.unpack(new File("/tmp/demo.zip"), new File("/tmp/demo"), new NameMapper() {
  public String map(String name) {
    return name.startsWith("doc/") ? name : null;
  }
});
//Extract a directory from a ZIP archive excluding the directory name
final String prefix = "doc/"; 
ZipUtil.unpack(new File("/tmp/demo.zip"), new File("/tmp/demo"), new NameMapper() {
  public String map(String name) {
    return name.startsWith(prefix) ? name.substring(prefix.length()) : name;
  }
});
//Print .class entry names in a ZIP archive
ZipUtil.iterate(new File("/tmp/demo.zip"), new ZipInfoCallback() {
  public void process(ZipEntry zipEntry) throws IOException {
    if (zipEntry.getName().endsWith(".class"))
      System.out.println("Found " + zipEntry.getName());
  }
});
//Print .txt entries in a ZIP archive (uses IoUtils from Commons IO)
ZipUtil.iterate(new File("/tmp/demo.zip"), new ZipEntryCallback() {
  public void process(InputStream in, ZipEntry zipEntry) throws IOException {
    if (zipEntry.getName().endsWith(".txt")) {
      System.out.println("Found " + zipEntry.getName());
      IOUtils.copy(in, System.out);
    }
  }
});

//Packing

//Compress a directory into a ZIP archive
ZipUtil.pack(new File("/tmp/demo"), new File("/tmp/demo.zip"));
//Compress a directory which becomes a ZIP archive
ZipUtil.unexplode(new File("/tmp/demo.zip"));
//Compress a directory into a ZIP archive with a parent directory
ZipUtil.pack(new File("/tmp/demo"), new File("/tmp/demo.zip"), new NameMapper() {
  public String map(String name) {
    return "foo/" + name;
  }
});
//Add an entry from file to a ZIP archive
ZipUtil.addEntry(new File("/tmp/demo.zip"), "doc/readme.txt", new File("f/tmp/oo.txt"), new File("/tmp/new.zip"));
//Add an entry from byte array to a ZIP archive
ZipUtil.addEntry(new File("/tmp/demo.zip"), "doc/readme.txt", "bar".getBytes(), new File("/tmp/new.zip"));
//Add an entry from file and from byte array to a ZIP archive
ZipEntrySource[] entries = new ZipEntrySource[] {
    new FileSource("doc/readme.txt", new File("foo.txt")),
    new ByteSource("sample.txt", "bar".getBytes())
};
ZipUtil.addEntries(new File("/tmp/demo.zip"), entries, new File("/tmp/new.zip"));
//Replace a ZIP archive entry from file
boolean replaced = ZipUtil.replaceEntry(new File("/tmp/demo.zip"), "doc/readme.txt", new File("/tmp/foo.txt"), new File("/tmp/new.zip"));
//Replace a ZIP archive entry from byte array
boolean replaced = ZipUtil.replaceEntry(new File("/tmp/demo.zip"), "doc/readme.txt", "bar".getBytes(), new File("/tmp/new.zip"));
//Replace a ZIP archive entry from file and byte array
ZipEntrySource[] entries = new ZipEntrySource[] {
    new FileSource("doc/readme.txt", new File("foo.txt")),
    new ByteSource("sample.txt", "bar".getBytes())
};
boolean replaced = ZipUtil.replaceEntries(new File("/tmp/demo.zip"), entries, new File("/tmp/new.zip"));

//Comparison

//Compare two ZIP archives (ignoring timestamps of the entries)
boolean equals = ZipUtil.archiveEquals(new File("/tmp/demo1.zip"), new File("/tmp/demo2.zip"));
//Compare two ZIP archive entries with same name (ignoring timestamps of the entries)
boolean equals = ZipUtil.entryEquals(new File("/tmp/demo1.zip"), new File("/tmp/demo2.zip"), "foo.txt");
//Compare two ZIP archive entries with different names (ignoring timestamps of the entries)
boolean equals = ZipUtil.entryEquals(new File("/tmp/demo1.zip"), new File("/tmp/demo2.zip"), "foo1.txt", "foo2.txt");

注：本文转载自：

http://www.aqee.net/development-tools-zt-zip/

https://github.com/zeroturnaround/zt-zip