从Android，无法连接到我的Java ServerSocket

Question

我是Java的初学者，我想在台式PC上创建服务器（运行外部IP地址，已验证），并在带有CM11的Samsung Galaxy S3上创建客户端。在服务器上：我在端口6666上创建了一个ServerSocket（不要问为什么），并在while（）中创建了Socket（server = .accept（）;）。

在客户端上：我创建了一个Socket客户端（client = new Socket（HostName，port）;），并将其放置在try {} catch（）{}中：如果连接失败，应用程序将显示在TextView“服务器已关闭进行维护”。

错误：我什至无法连接到我的服务器，但是外部IP可以通过终端仿真器进行ping操作...我不知道为什么。我的客户端，服务器上是否有错误，还是我需要在清单（android）中添加权限？（应用运行时，Android不会在控制台中返回任何错误）-

任何的想法？这就是为什么我不想显示应用程序的名称。

服务器：

    package <HIDDEN>;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;

public class MainClass {
    public static final String version ="0.1A";
    public static final int port = 6666;
    private static ServerSocket Service;
    private static DataInputStream fromClient;
    private static DataOutputStream toClient;
    private static Socket server;
    static InetAddress Host;

    public static void main(String[] args)  {

        System.out.println("Welcome to <HIDDEN>'s Server! Version ## "+version+" ##");



        try {
            Service = new ServerSocket(port); // INITIALIZE SERVER SOCKET
            System.out.println("Socket created at "+Service.getInetAddress()+"  ");
        } catch (IOException e) {
            System.err.println("Error While Creating ServerSocket ' Service ' !!!\n");
            e.printStackTrace();

        }

        while(true) {
            try {
            server = Service.accept();
            System.out.println("Opened Socket on ");
            if(server != null ) {System.out.println("ACCEPTING CONNECTION!");}
            fromClient = new DataInputStream(server.getInputStream());              //  INITIALIZE AND ACCEPT   SOCKET
            toClient = new DataOutputStream(server.getOutputStream());              //  CONNECTION  AND STREAMS

            toClient.writeBoolean(com.<HIDDEN>.FileLoader.verifyLogger(String.valueOf(fromClient.readChar())));

            } catch(IOException e) {
                System.err.println("Error While Initializing A Dialog With Client! "+ "\033FATAL ERROR\033");
                e.printStackTrace();
            }
        }
    }

}

客户端：[仅JAVA文件]

package <HIDDEN>;

import android.app.Activity;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;


public class login_activity extends Activity {
    public static String username, password;
    public static final String HostName = "84.227.165.225";
    public static final int port = 6666;
    private Socket client;
    private DataOutputStream toServer;
    private DataInputStream fromServer;

    @Override
    protected void onCreate(Bundle savedInstanceState) { /*ONCREATE VOID*/
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
    }


    public void Login(View view) {
        EditText username_et = (EditText) findViewById(R.id.username_et); // EditTexts
        EditText password_et = (EditText) findViewById(R.id.password_et); //---
        TextView instructions_tw = (TextView) findViewById(R.id.instructions_tw);
        password = password_et.getText().toString();
        username = username_et.getText().toString();
        try {
            client = new Socket(HostName, port); //INITIALIZE SOCKET
            System.out.print("Initialized Socket, connecting to Server "+HostName+":"+port+"\n");
            toServer = new DataOutputStream(client.getOutputStream()); //System.out.print doesn't works on android...
        }catch (Exception UnkownHostException) {
            instructions_tw.setText("Please Log In Or Register To <NOPE, LOL>\n\n!! THE SERVER IS DOWN FOR MAINTENANCE");
        }

        try {
            toServer.writeBytes(username+"???"+password);
            fromServer = new DataInputStream(client.getInputStream());
            boolean accepted = false;
            if(fromServer.readBoolean()) {
                Intent i = new Intent(this, mainmenu_activity.class);
                startService(i);
            } else {instructions_tw.setText("Please Log In Or Register To <HIDDEN>\n\n!! UNCORRECT PASSWORD OR USERNAME");}
/* THE CODE IS NEVER GOING TO THIS WAY ;( */
        }catch(Exception UnkownHostException){

        }


    }
}

感谢帮助

Answer 1

我认为您需要向INTERNET清单文件中添加权限，以便能够使用来自android的网络套接字。

Android文档说：

INTERNET允许应用程序打开网络套接字。

您应该在清单文件中添加以下内容：

<uses-permission android:name="android.permission.INTERNET" />

添加-还请确保可以从Android设备访问服务器：服务器和设备都应位于同一网络（WiFi连接）中，或者应该可以从Internet访问服务器。