Question

更新一：通过使用TCP port checker，我能够验证AWS实例上的端口8080是否处于活动状态并接受连接。
这意味着端口可能不会以某种方式正确绑定，如果我设法解决此问题，将更新回来此外，通过使用AWS服务器实例日志，/var/log/nginx/error.log下的条目表明连接被拒绝，尽管访问协议不受限制。

我有一个基于Socket的服务器，在localhost上运行完全正常。我启动服务器，然后启动实例客户端调用，行为符合预期和期望;服务器返回＆＃34; Hello World＆＃34;到客户端并终止连接但是，如果我将服务器上传到AWS并将其作为Java应用程序托管，我就无法建立连接并重现localhost服务的行为。

HelloWorldServer：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class NetMiddlewareServer {

    public static void main(String[] args) {
        // TODO code application logic here
        int portNumber = 8080;
        while(true){
            try ( 
            ServerSocket serverSocket = new ServerSocket(portNumber);
            Socket clientSocket = serverSocket.accept();
            PrintWriter out =
                new PrintWriter(clientSocket.getOutputStream(), true);
            BufferedReader in = new BufferedReader(
                new InputStreamReader(clientSocket.getInputStream()));
        ) {

            System.out.println("Test");
            String inputLine, outputLine;

            // Initiate conversation with client
            outputLine = "Hello World";
            out.println(outputLine);

            clientSocket.close();

        } catch (IOException e) {
            System.out.println("Exception caught when trying to listen on port "
                + portNumber + " or listening for a connection");
            System.out.println(e.getMessage());
        }
        }
}

HelloWorldClient：

import java.io.*;
import java.net.*;

public class KKPClient {
public static void main(String[] args) throws IOException {

    String hostName = "localhost";
    int portNumber = 8080;

    try (
        Socket hwSocket = new Socket(hostName, portNumber);
        PrintWriter out = new PrintWriter(hwSocket.getOutputStream(), true);
        BufferedReader in = new BufferedReader(
            new InputStreamReader(hwSocket.getInputStream()));
    ) {
        BufferedReader stdIn =
            new BufferedReader(new InputStreamReader(System.in));
        String fromServer;

        while ((fromServer = in.readLine()) != null) {
            System.out.println("Server: " + fromServer);
        }

    } catch (UnknownHostException e) {
        System.err.println("Don't know about host " + hostName);
        System.exit(1);
    } 
    catch (IOException e) {
        System.err.println("Couldn't get I/O for the connection to " +
            hostName);
        System.exit(1);
    }
}

}

上述代码在本地运行完全正常，但是将服务器上传到AWS并更改hostName会导致错误，我相信这就是问题所在。服务器实例的IP地址（例如，52.214.166.199）未连接，并且在尝试声明Socket hwSocket时抛出IOException。由于未正确创建Socket，因此未返回任何输入，因此未收到Hello World消息。

非常感谢任何帮助，谢谢。

堆栈追踪：

Exception in thread "main" java.net.SocketException: Socket is not connected: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at java.net.Socket.connect(Socket.java:538)
at java.net.Socket.<init>(Socket.java:434)
at java.net.Socket.<init>(Socket.java:211)
at kkpclient.KKPClient.main(hwClient.java:19)
C:\Users\[me]\AppData\Local\NetBeans\Cache\8.1\executor-snippets\run.xml:53: Java returned: 1

无法连接到AWS上的基于Socket的服务器

0 个答案: