当我使用spring集成作为tcp客户端时，我如何向服务器发送EOF信号

Question

我想使用spring集成来替换socket客户端。我的套接字客户端代码如下：

public static void main(String[] args) {
try {
Socket socket = new Socket("localhost", 7779);
OutputStream os = socket.getOutputStream();
PrintWriter pw = new PrintWriter(os);
String str = "hello server!";
pw.write(str);
pw.flush();
socket.shutdownOutput();
InputStream is = socket.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(is));
String info = br.readLine();
while (info != null) {
System.out.println("i am client. server says that " + info);
info = br.readLine();
pw.close();
}
br.close();
is.close();
pw.close();
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}

套接字客户端将获得服务器的回复消息。我用spring-integration来做同样的工作。spring集成的xml代码如下：

<int:gateway id="gw"
service-interface="org.springframework.integration.samples.tcpclientserver.SimpleGateway"
default-request-channel="input"/>
<int-ip:tcp-connection-factory id="client"
type="client"
host="localhost"
port="7779"
single-use="true"
so-timeout="10000"/>
<int:channel id="input"/>
<int-ip:tcp-outbound-gateway id="outGateway"
request-channel="input"
reply-channel="clientBytes2StringChannel"
connection-factory="client"
request-timeout="10000"
reply-timeout="10000"/>
<int:object-to-string-transformer id="clientBytes2String"
input-channel="clientBytes2StringChannel"/>

这是springintegration的tcp客户端服务器示例的一部分https://github.com/spring-projects/spring-integration-samples/tree/master/basic/tcp-client-server

java代码如下：

final Scanner scanner = new Scanner(System.in);
final GenericXmlApplicationContext context = Main.setupContext();
final SimpleGateway gateway = context.getBean(SimpleGateway.class);
final AbstractServerConnectionFactory crLfServer = context.getBean(AbstractServerConnectionFactory.class);
TestingUtilities.waitListening(crLfServer, 10000L);
while (true) {
final String input = scanner.nextLine();
if ("q".equals(input.trim())) {
break;
}
else {
final String result = gateway.send(input);
System.out.println(result);
}
}
System.out.println("Exiting application...bye.");
System.exit(0);
}
public static GenericXmlApplicationContext setupContext() {
final GenericXmlApplicationContext context = new GenericXmlApplicationContext();
if (System.getProperty(AVAILABLE_SERVER_SOCKET) == null) {
System.out.print("Detect open server socket...");
int availableServerSocket = SocketUtils.findAvailableTcpPort(5678);
final Map<String, Object> sockets = new HashMap<>();
sockets.put(AVAILABLE_SERVER_SOCKET, availableServerSocket);
final MapPropertySource propertySource = new MapPropertySource("sockets", sockets);
context.getEnvironment().getPropertySources().addLast(propertySource);
}
System.out.println("using port " + context.getEnvironment().getProperty(AVAILABLE_SERVER_SOCKET));
context.load("classpath:META-INF/spring/integration/tcpClientServerDemo-context.xml");
context.registerShutdownHook();
context.refresh();
return context;
}

我无法得到服务器的回复，因为服务器没有得到eof信号，它仍然在readLine()中被阻止；我得到的例外：org.springframework.integration.MessageTimeoutException：等待响应时超时。

这是服务器代码：

try {
ServerSocket serverSocket = new ServerSocket(7779);
Socket socket = serverSocket.accept();
InputStream is = socket.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String info = br.readLine();
System.out.println("from client : "+info);
while (info != null) {
System.out.println("i am server. message from client is " + info);
info = br.readLine(); //server blocked here
}
socket.shutdownInput();
OutputStream os = socket.getOutputStream();
String replyMsg="welcom from server 7779 ACKrn";
os.write(replyMsg.getBytes());
os.close();
br.close();
isr.close();
is.close();
socket.close();
serverSocket.close();
} catch (IOException e) {
e.printStackTrace();
}

那么我如何向服务器发送eof信号，以便我的应用程序得到服务器的回复呢？

Answer 1

Spring Integration目前不支持那些shutDown*()方法。

请打开一个GitHub问题，我们将进行查看。