全部，
这是我第一次在这里发帖——过去几天我已经搜索了几个小时。这不是我制作的第一个客户端/服务器应用程序，我完全不知道出了什么问题。
我有一个 Java 服务器（它能够正确读取来自我的 iOS 客户端的请求——它甚至会生成一个响应并且似乎可以正确发送它，尽管在 iOS 客户端上没有可读取的数据）：
public void run() {
BufferedReader in;
try {
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
OutputStream out_stream = this.socket.getOutputStream();
StringBuilder request = new StringBuilder();
String request_buffer;
while ((request_buffer = in.readLine()) != null) {
request.append(request_buffer);
}
out_stream.write(processRequest(request.toString()).getBytes());
out_stream.close();
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
提供的 Java 函数作为生成它所属的类的实例的结果而被调用，并使用 ServerSocket 的 accept() 方法的结果进行初始化。一切似乎都在这里正常工作——以下 Python 客户端能够发送请求（甚至读取响应）：
DEFAULT_HOST = ''
DEFAULT_PORT = 2012
RECEIVE_BUFFER_SIZE = 4096
if __name__ == "__main__":
import sys, socket
port = DEFAULT_PORT
host = DEFAULT_HOST
if len(sys.argv) > 2:
host = sys.argv[1]
del sys.argv[1]
if len(sys.argv) == 2:
request = sys.argv[1]
print "Requesting: %s" % request
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
s.send(request)
s.shutdown(socket.SHUT_WR)
response = ""
message = True
while message:
message = s.recv(RECEIVE_BUFFER_SIZE)
response += message
print "Response: %s" % response
在发布 iOS 客户端之前，我已经使用以下 Python 服务器对其进行了测试（并且 iOS 客户端可以按预期读取/写入。这也适用于 Python 测试客户端）：
import os, sys
DEFAULT_HOST = ''
DEFAULT_PORT = 4150
# Simple test server
DEFAULT_SIZE = 4096
import socket
class Server:
def __init__(self, host, port, root, protocol, debug=True):
self.debug = debug
self.host = host
self.port = port
self.root = root
self.protocol = protocol
def __call__(self):
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((self.host, self.port))
s.listen(5)
while True:
try:
c = s.accept()
print "Connection: %s" % str(c)
request = c[0].recv(DEFAULT_SIZE)
print "Request: %s" % request
try:
response = "test"
if self.debug:
print "Response: %s" % response
except Exception as ex:
print "Error generating response: %s" % ex
if response:
c[0].send(response)
else:
c[0].send("3rr0rZ")
c[0].close()
print
except Exception as ex:
print ex
if __name__ == "__main__":
host = DEFAULT_HOST
port = DEFAULT_PORT
args = sys.argv
# choose a port
if len(args) > 1 and args[1] == "-p":
if len(args) < 3:
raise Exception("Missing Argument for %s" % "-p")
port = int(args[2])
del args[1:3]
else:
port = DEFAULT_PORT
# check if root specified
if len(args) > 1:
root = os.path.realpath(args[1])
del args[1]
else:
root = os.getcwd()
print "Using:"
print "\tHost: %s" % host
print "\tPort: %s" % port
print "\tRoot: %s" % root
print
server = Server(host, port, root)
server()
显然这是一个简化的服务器——问题不在于如何生成请求。对于更多背景知识，请求和响应是 JSON 字符串，尽管这并不完全相关。如前所述，Python 客户端能够成功地请求和接收来自 Java 和 Python 服务器的响应。iOS 客户端可以成功地向 Python 和 Java 服务器发送请求，但它只能从 Python 服务器读取响应。这是iOS客户端的相关部分：
- (NSData *)sendMessage:(NSData *)request
{
// Create low-level read/write stream objects
CFReadStreamRef readStream = nil;
CFWriteStreamRef writeStream = nil;
// Create high-level stream objects
NSInputStream *inputStream = nil;
NSOutputStream *outputStream = nil;
// Connect the read/write streams to a socket
CFStreamCreatePairWithSocketToHost(nil, (__bridge CFStringRef) self.address, self.port, &readStream, &writeStream);
// Create input/output streams for the raw read/write streams
if (readStream && writeStream) {
CFReadStreamSetProperty(readStream, kCFStreamPropertyShouldCloseNativeSocket, kCFBooleanTrue);
CFWriteStreamSetProperty(writeStream, kCFStreamPropertyShouldCloseNativeSocket, kCFBooleanTrue);
inputStream = (__bridge_transfer NSInputStream *)readStream;
[inputStream open];
outputStream = (__bridge_transfer NSOutputStream *)writeStream;
[outputStream open];
}
NSLog(@"Sending message to server: %@", request);
[outputStream write:[request bytes] maxLength:[request length]];
[outputStream close];
int size;
int buffer_size = 1024;
uint8_t buffer[buffer_size];
NSMutableData *response = [NSMutableData dataWithLength:0];
while (![inputStream hasBytesAvailable]);
NSLog(@"About to read");
while ([inputStream streamStatus] == NSStreamStatusOpen)
{
if ([inputStream hasBytesAvailable] && (size = [inputStream read:buffer maxLength:buffer_size]) > 0)
{
NSLog(@"Reading response data");
[response appendData:[NSData dataWithBytes:buffer length:size]];
}
}
NSLog(@"\tResponse:%@", response);
return response;
}
从 Java 服务器读取时，iOS 客户端永远不会超过以下行：
while (![inputStream hasBytesAvailable]);
我已经阅读了所有可以找到各种搜索词的文档、论坛帖子、问题等，但没有任何帮助；我希望这里有人可以阐明这个问题！我已经发布了我正在使用的代码的稍微简化/扁平化的版本，但是，再次，这应该足以建立上下文。如果有必要，我会很乐意发布更多代码，我感谢任何帮助或洞察力你可以分享。
我故意不使用 NSStreamDelegate，我无法想象这是一个问题。如果我是，我会想象问题会简单地转化为 NSStreamEventHasBytesAvailable 永远不会发生。