...
<dependency>
    <groupId>org.zeroturnaround</groupId>
    <artifactId>zt-zip</artifactId>
    <version>1.11</version>
    <type>jar</type>
</dependency>
...

boolean exists = ZipUtil.containsEntry(new File("/tmp/demo.zip"), "foo.txt");

byte[] bytes = ZipUtil.unpackEntry(new File("/tmp/demo.zip"), "foo.txt");

byte[] bytes = ZipUtil.unpackEntry(new File("/tmp/demo.zip"), "foo.txt", Charset.forName("IBM437"));

ZipUtil.unpackEntry(new File("/tmp/demo.zip"), "foo.txt", new File("/tmp/bar.txt"));

ZipUtil.unpack(new File("/tmp/demo.zip"), new File("/tmp/demo"));

ZipUtil.explode(new File("/tmp/demo.zip"));

ZipUtil.unpack(new File("/tmp/demo.zip"), new File("/tmp/demo"), new NameMapper() {
  public String map(String name) {
    return name.startsWith("doc/") ? name : null;
  }
});

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;
  }
});

ZipUtil.unpack(new File("/tmp/demo.zip"), new File("/tmp/demo"), new NameMapper() {
  public String map(String name) {
    if (name.contains("/doc")) {
      return name;
    }
    else {
      // returning null from the map method will disregard the entry
      return null;
    }
  }
});

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());
  }
});

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);
    }
  }
});

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

ZipUtil.unexplode(new File("/tmp/demo.zip"));

ZipUtil.pack(new File("/tmp/demo"), new File("/tmp/demo.zip"), new NameMapper() {
  public String map(String name) {
    return "foo/" + name;
  }
});

ZipUtil.addEntry(new File("/tmp/demo.zip"), "doc/readme.txt", new File("f/tmp/oo.txt"), new File("/tmp/new.zip"));

ZipUtil.addEntry(new File("/tmp/demo.zip"), "doc/readme.txt", "bar".getBytes(), new File("/tmp/new.zip"));

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"));

ZipEntrySource[] entries = new ZipEntrySource[] {
    new FileSource("doc/readme.txt", new File("foo.txt")),
    new ByteSource("sample.txt", "bar".getBytes())
};
OutputStream out = null;
try {
  out = new BufferedOutputStream(new FileOutputStream(new File("/tmp/new.zip")));
  ZipUtil.addEntries(new File("/tmp/demo.zip"), entries, out);
}
finally {
  IOUtils.closeQuietly(out);
}

boolean replaced = ZipUtil.replaceEntry(new File("/tmp/demo.zip"), "doc/readme.txt", new File("/tmp/foo.txt"), new File("/tmp/new.zip"));

boolean replaced = ZipUtil.replaceEntry(new File("/tmp/demo.zip"), "doc/readme.txt", "bar".getBytes(), new File("/tmp/new.zip"));

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"));

ZipEntrySource[] addedEntries = new ZipEntrySource[] {
        new FileSource("/path/in/zip/File1.txt", new File("/tmp/file1.txt")),
        new FileSource("/path/in/zip/File2.txt", new File("/tmp/file2.txt")),
        new FileSource("/path/in/zip/File3.txt", new File("/tmp/file2.txt")),
    };
ZipUtil.addOrReplaceEntries(new File("/tmp/demo.zip"), addedEntries);

boolean transformed = ZipUtil.transformEntry(new File("/tmp/demo"), "sample.txt", new StringZipEntryTransformer() {
    protected String transform(ZipEntry zipEntry, String input) throws IOException {
        return input.toUpperCase();
    }
}, new File("/tmp/demo.zip"));

boolean equals = ZipUtil.archiveEquals(new File("/tmp/demo1.zip"), new File("/tmp/demo2.zip"));

boolean equals = ZipUtil.entryEquals(new File("/tmp/demo1.zip"), new File("/tmp/demo2.zip"), "foo.txt");

boolean equals = ZipUtil.entryEquals(new File("/tmp/demo1.zip"), new File("/tmp/demo2.zip"), "foo1.txt", "foo2.txt");