Question

我在“Hello world”客户端/服务器应用程序上工作，我正在努力解决服务器之间的连接，该连接是用 scala <编写的/ strong>并在我的PC和客户端上运行，该文件以 android 编写并在我的手机上运行。

我连接了同一子网上的两个应用程序，即。我的路由器并为它们设置相应的IP和端口。问题是用Android编写的客户端会立即停止。

P.S。出于安全原因，我没有发布我的IP地址。

服务器代码是：

import java.net._ import java.io._ import scala.io._ object MyServer extends App { try { val server = new ServerSocket(4242) println("Serve initialized:") val client = server.accept val in = new BufferedReader(new InputStreamReader(client.getInputStream())) val out = new PrintStream(client.getOutputStream()) var message =in.readLine() while(message != null) { println("Server received:" + message) out.println("Message received") out.flush if (message.equals("Disconnect")) { client.close; server.close; println("Server closing:") } message= in.readLine() } } catch { case e: Exception => println(e.getStackTrace); System.exit(1) } }

客户端代码是：

activity_main.xml：

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.ghiurutan.clientv1.MainActivity"> <Button android:text="@string/button_text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/button" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:layout_marginBottom="158dp" /> <TextView android:text="@string/text_view_text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignTop="@+id/editText" android:layout_alignParentLeft="true" android:layout_alignParentStart="true" android:id="@+id/textView" android:layout_alignBottom="@+id/editText" android:layout_toLeftOf="@+id/button" android:layout_toStartOf="@+id/button" /> <EditText android:layout_width="wrap_content" android:layout_height="wrap_content" android:inputType="textPersonName" android:ems="10" android:id="@+id/editText" android:layout_marginBottom="125dp" android:layout_alignBottom="@+id/button" android:layout_alignParentRight="true" android:layout_alignParentEnd="true" /> </RelativeLayout>

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.ghiurutan.clientv1"> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>

MainActivity.java

package com.example.ghiurutan.clientv1; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import java.io.*; import java.net.*; import android.view.View; import android.widget.*; public class MainActivity extends AppCompatActivity { private Socket socket; private static final int SERVER_PORT=4242; private static final String SERVER_IP=""; private EditText editText; private Button button; private PrintWriter printWriter; private String messageToSend; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); new Thread( new Runnable() { public void run() { try{ socket=new Socket(InetAddress.getByName(SERVER_IP),SERVER_PORT); }catch(UnknownHostException e) { System.out.println(e.getLocalizedMessage()); }catch(IOException e) { System.out.println(e.getLocalizedMessage()); } } } ).start(); } @Override protected void onStart() { super.onStart(); try{ printWriter=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true); }catch(UnknownHostException e) { System.out.println(e.getLocalizedMessage()); }catch(IOException e) { System.out.println(e.getLocalizedMessage()); } editText=(EditText)findViewById(R.id.editText); button=(Button)findViewById(R.id.button); button.setOnClickListener( new Button.OnClickListener() { public void onClick(View v) { messageToSend=editText.getText().toString(); editText.setText(""); printWriter.println(messageToSend); } } ); } @Override protected void onResume() { super.onResume(); } @Override protected void onPause() { super.onPause(); } @Override public void onDestroy() { super.onDestroy(); } }

我必须提到我只是编程的初学者，所以欢迎任何帮助或建议。在这种情况下我应该使用端口转发吗？有人告诉我，将服务器放在云端是个好主意，因为这样会更加明显。

Answer 1

实际可行的最终代码如下：

package com.example.ghiurutan.clientv1;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import java.io.*;
import java.net.*;
import android.view.View;
import android.widget.*;



public class MainActivity extends AppCompatActivity {
    private Socket socket;
    private static final int SERVER_PORT=8888;
    private static final String SERVER_IP="192.168.100.2";
    private EditText currentEditText,destinationEditText;
    private TextView resultTextView;
    private Button button;
    private PrintWriter printWriter;
    private BufferedReader bufferedReader;
    private String currentLocationMessage,
    destinationLocationMessage,messageReceived;

//Called when the activity is first created
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        button=(Button)findViewById(R.id.button);
        currentEditText=(EditText)findViewById(R.id.editText1);
        destinationEditText=(EditText)findViewById(R.id.editText2);
        resultTextView=(TextView)findViewById(R.id.textView4);


        button.setOnClickListener(
                    new Button.OnClickListener() {
                    public void onClick(View v) {

                        currentLocationMessage = currentEditText.getText().toString();
                        destinationLocationMessage=destinationEditText.getText().toString();
                        currentEditText.setText("");
                        destinationEditText.setText("");
                        new Thread(new SendMessage()).start();
                    }
                }
        );
    }


    private class SendMessage implements Runnable {
        public void run() {
            try {
                String inputMessage=currentLocationMessage+"#"+destinationLocationMessage;
                socket = new Socket(InetAddress.getByName(SERVER_IP), SERVER_PORT);
                printWriter = new PrintWriter(socket.getOutputStream());
                bufferedReader=new BufferedReader(new InputStreamReader(socket.getInputStream()));
                printWriter.println(inputMessage);
                printWriter.flush();
                currentLocationMessage="";
                destinationLocationMessage="";
                messageReceived = bufferedReader.readLine();

               runOnUiThread(new Runnable(){
                   @Override
                   public void run()
                   {
                       if(messageReceived==null || messageReceived.equals(""))
                       {
                           resultTextView.setText("Error.Please check the inputs.");
                       }else {
                           resultTextView.setText(messageReceived);
                       }
                   }
               });
                printWriter.close();
                bufferedReader.close();
                socket.close();

            } catch (UnknownHostException e) {
                System.out.println(e.getLocalizedMessage());
            } catch (IOException e) {
                System.out.println(e.getLocalizedMessage());
            }
        }

    }


//Called when the activity is about to become visible
    @Override
    protected void onStart()
    {
        super.onStart();
    }

    //Called when the activity has become visible
    @Override
    protected void onResume()
    {
        super.onResume();
    }

    //Called when another activity is taking focus
    @Override
    protected void onPause()
    {
        super.onPause();
    }

    //Called before the activity is destroyed
    @Override
    public void onDestroy()
    {
        super.onDestroy();
    }
}

使用套接字的简单客户端 - 服务器应用

1 个答案: