Question

我在从Java客户端向python服务器发送TCP消息时遇到一些奇怪的行为，特别是在使用write(byte[] b)和writeBytes(String s)时存在差异。

我正在使用找到here的python服务器，缓冲区大小设置为1024（发送的消息很少超过100个字节，永远不会超过200个）：

#!/usr/bin/env python
# encoding: utf-8
#
# Copyright (c) 2010 Doug Hellmann.  All rights reserved.
#
"""Server half of echo example.
"""
#end_pymotw_header

import socket
import sys

# Create a TCP/IP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# Bind the socket to the port
server_address = ('localhost', 39277)
print >>sys.stderr, 'starting up on %s port %s' % server_address
sock.bind(server_address)

# Listen for incoming connections
sock.listen(1)

while True:
    # Wait for a connection
    print >>sys.stderr, 'waiting for a connection'
    connection, client_address = sock.accept()
    try:
        print >>sys.stderr, 'connection from', client_address

        # Receive the data in small chunks and retransmit it
        while True:
            data = connection.recv(1024)
            #print >>sys.stderr, 'received "%s"' % data
            if data:
                print >>sys.stderr, 'received "%s"' % data
            else:
                print >>sys.stderr, 'no more data from', client_address
                break
    finally:
        # Clean up the connection
        connection.close()

当我使用writeBytes(msg)时，python服务器会分割消息：

starting up on localhost port 39277
waiting for a connection
connection from ('127.0.0.1', 53948)
received "$PNG"
received "VEST,LOCATION,1,144291"
received "1960"
received "50"
received "7,"
....

但是当我将字符串转换为字节数组时：

byte[] b = msg.getBytes();
DataOutputStream.write(b);

它没有拆分消息，并按预期收到消息：

connection from ('127.0.0.1', 53956)
received "$PNGVEST,LOCATION,1,1442912048641,,,,,,0"
received "$PNGVEST,LOCATION,1,1442912049655,51.55866171044861,-3.0430628338367187,0.0,1.25,148.87440204525353,0"
received "$PNGVEST,LOCATION,1,1442912050656,51.5586532525196,-3.043054619198384,0.0,1.25,148.87440290497682,0"

为什么会这样？

使用python套接字时，Java DataOutputStream write和writeBytes具有不同的行为

0 个答案: