斗鱼弹幕抓取的最小实现

Main.java

package wit.feng.simplesocket;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;


public class Main {

	public static void main(String[] args) throws Exception {
		work();
	}
	public static void work() throws Exception
	{
		Socket ss = new Socket(); 
		SocketAddress endpoint = new InetSocketAddress("danmu.douyu.com",12604);
		ss.connect(endpoint);
		String logininfo="type@=loginreq/roomid@=291514/";
		OutputStream os = ss.getOutputStream();
		os.write(sendMsgWraper(logininfo));
		InputStream is = ss.getInputStream();
		System.out.println("wait...");
		boolean isentergroup = false;
		while(!ss.isClosed())
		{
			readMessage(is);
			if(!isentergroup)
			{
				isentergroup = true;
				System.out.println("send joingroup");
				String joingrop = "type@=joingroup/rid@=291514/gid@=-9999/";
				os.write(sendMsgWraper(joingrop));
			}
		}
		ss.close();
	}
	public static void readMessage(InputStream is) throws IOException
	{
		byte [] buf =new byte[4];
		int sizereadlen= is.read(buf);
		if(sizereadlen !=4)
		{
			System.out.println("error not read size");
			System.exit(0);
		}
		int size  = ntohl(buf);
//		System.out.println("size:"+size);
		// 不考虑效率
		byte [] databuffer = new byte[size];

		int alreadyReadLen  = 0;
		while(alreadyReadLen < size)
		{
//			System.out.println("start read");
			int readlen = is.read(databuffer,alreadyReadLen,size-alreadyReadLen);
//			System.out.println("read len:"+readlen);
			alreadyReadLen += readlen;
//			System.out.println("already total :"+alreadyReadLen);
		}
		byte [] strbuff = new byte[size-9];
		System.arraycopy(databuffer,8,strbuff,0,size-9);
		String text = new String(strbuff,"UTF-8");
		System.out.println(text);
	}
	
	public static byte [] sendMsgWraper(String sendmsg) throws Exception{
		byte[] endbys = {0};
		byte[] bys = sendmsg.getBytes("UTF-8");
		int len = bys.length;
		byte [] headersize = htonl(len+9);
		byte [] type= htons((short)689);
		ByteBuffer byb = ByteBuffer.allocate(len+13);
		byb.put(headersize);
		byb.put(headersize);
		byb.put(type);
		byb.putShort((short)0);
		byb.put(bys);
		byb.put(endbys);
		return byb.array();
	}
	
	public static int ntohl(byte [] bys)
	{
		return ByteBuffer.wrap(bys).order(ByteOrder.LITTLE_ENDIAN).getInt();
	}

	public static byte[] htonl(int i)
	{
		return ByteBuffer.allocate(4).order(ByteOrder.LITTLE_ENDIAN).putInt(i).array();
	}
	
	public static byte[] htons(short i)
	{
		return ByteBuffer.allocate(2).order(ByteOrder.LITTLE_ENDIAN).putShort(i).array();
	}
}