Netty编解码技术和UDP实现(3)

public static byte[] gzip(byte[] data) throws Exception {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        GZIPOutputStream gzip = new GZIPOutputStream(bos);
        gzip.write(data);
        gzip.finish();
        gzip.close();
        byte[] ret = bos.toByteArray();
        bos.close();
        return ret;
    }

public static byte[] ungzip(byte[] data) throws Exception {
        ByteArrayInputStream bis = new ByteArrayInputStream(data);
        GZIPInputStream gzip = new GZIPInputStream(bis);
        byte[] buf = new byte[1024];
        int num = -1;
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        while ((num = gzip.read(buf, 0, buf.length)) != -1) {
            bos.write(buf, 0, num);
        }
        gzip.close();
        bis.close();
        byte[] ret = bos.toByteArray();
        bos.flush();
        bos.close();
        return ret;
    }

public static void main(String[] args) throws Exception {

// 读取文件
        String readPath = System.getProperty("user.dir") + File.separatorChar + "sources" + File.separatorChar
                + "006.jpg";
        File file = new File(readPath);
        FileInputStream in = new FileInputStream(file);
        byte[] data = new byte[in.available()];
        in.read(data);
        in.close();

System.out.println("文件原始大小:" + data.length);
        // 测试压缩

byte[] ret1 = GzipUtils.gzip(data);
        System.out.println("压缩之后大小:" + ret1.length);

byte[] ret2 = GzipUtils.ungzip(ret1);
        System.out.println("还原之后大小:" + ret2.length);

// 写出文件
        String writePath = System.getProperty("user.dir") + File.separatorChar + "receive" + File.separatorChar
                + "006.jpg";
        FileOutputStream fos = new FileOutputStream(writePath);
        fos.write(ret2);
        fos.close();
    }
}

UDP的实现

代码示例：

public class Server {
    public void run(int port) throws Exception {
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(group).channel(NioDatagramChannel.class).option(ChannelOption.SO_BROADCAST, true)
                    .handler(new ServerHandler());
            b.bind(port).sync().channel().closeFuture().await();
        } finally {
            group.shutdownGracefully();
        }
    }