通过套接字发送和接收数据：Node.JS 服务器、Java 客户端

Question

I'm trying to send data from a Node JS net server to a java application. Here's my JS code:

    var server = net.createServer(function (c) { //'connection' listener
    console.log('server connected');
    c.on('end', function () {
        console.log('server disconnected');
    });
    c.on('data', (d) => {
        console.log(data);
    });
    c.pipe(c);
    setInterval(() => {
        let obj = { "foo": "bar" };
        c.write(JSON.stringify(obj));
    }, 3000)
});
server.listen(58430, function () { //'listening' listener
    console.log('server bound');
}); 

So I'm just debugging for now, and trying to send data (foo:bar) on an interval.

Here's my java side, running in a loop:

        InputStreamReader inFromClient = new InputStreamReader(client.getInputStream());
        while (running.get()) {
            String data = Tools.ReadUntilNull(inFromClient);
            Log.debug("Received: " + data);
        }

where 'client' is a socket listening on the correct port. 'running' is an atomic boolean that is true.

Tools.ReadUntilNull corresponds to this:

public static String ReadUntilNull(InputStreamReader reader) throws IOException {
    StringBuilder sb = new StringBuilder();
    char[] results = new char[1];
    int bytes_read = reader.read(results);
    while (results[0] != 0x00 && bytes_read == 1) {
        sb.append(results[0]);
        bytes_read = reader.read(results);
    }

    return sb.toString();
}

My Node.JS app logs that the server is bound & connected. Only when I send data I can't seem to receive it in my Java client.

I'm just learning about java so please be easy on me ^^

Answer 1

I think you are just doing wrong. As you mentioned, You are trying to read on java side. Then you should create nodejs client. Verify the same.

More: https://nodejs.org/api/net.html#net_net_createconnection

const net = require('net');
const client = net.createConnection({ port: 8124 }, () => {
  // 'connect' listener.
  console.log('connected to server!');
  client.write('world!\r\n');
});
client.on('data', (data) => {
  console.log(data.toString());
  client.end();
});
client.on('end', () => {
  console.log('disconnected from server');
});