此java代码的等效nodejs代码

Question

我看到了这段java代码，链接：java套接字发送&接收字节阵列

Socket socket = ...
DataInputStream dIn = new DataInputStream(socket.getInputStream());
int length = dIn.readInt();                    // read length of incoming message
if(length>0) {
    byte[] message = new byte[length];
    dIn.readFully(message, 0, message.length); // read the message
}

我只是想知道他们在node.js中是否是等效的代码？？

Answer 1

只需从套接字中读取4个字节，将其转换为32位有符号大端整数，然后读取更多字节：

function readLength(cb) {
  var length = socket.read(4);
  if (length === null)
    socket.once('readable', function() { readLength(cb); });
  else
    cb(length.readInt32BE(0, true));
}
function readMessage(cb) {
  readLength(function retry(len) {
    var message = socket.read(len);
    if (message === null)
      socket.once('readable', function() { retry(len); });
    else
      cb(message);
  });
}
// ...
readMessage(function(msg) {
  // `msg` is a Buffer containing your message
});