从 Android 应用程序通过 TCP 发送数据

Question

我正在尝试从 Android 应用程序发送数据 客户端类src：

import java.io.*;
import java.net.Socket;
import java.net.UnknownHostException;

public class CClient    
implements Runnable     
{
    private Socket socket;
    private String ServerIP = "10.0.0.14";


    public void run()
    {
        try 
        {
            socket = new Socket("10.0.0.14", 16606);

        }
        catch(Exception e) 
        {
            System.out.print("Whoops! It didn't work!:");
            System.out.print(e.getLocalizedMessage());
            System.out.print("\n");
        }
    }

    public void Send(String s)
    {
        try
        {
            PrintWriter outToServer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()));
            outToServer.print(s + "\n");
            outToServer.flush();


        }
        catch (UnknownHostException e) {
            System.out.print(e.toString());
        } catch (IOException e) {
            System.out.print(e.toString());
        }catch (Exception e) {
            System.out.print(e.toString());
        }

    }
}

在活动中使用 CClient 类来创建连接和发送数据。 这是活动代码

import android.os.Bundle;
import android.app.Activity;
import android.view.*;
import android.widget.*;


public class Auth extends Activity {

    private ProgressBar mProgress;
    private TextView mTV;

    private CClient mClient;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_auth);


        mProgress = (ProgressBar) findViewById(R.id.progressBar1);
        mTV =  (TextView) findViewById(R.id.textView4);

        mClient = new CClient();                
        Thread myThready = new Thread(mClient);
        myThready.start();  

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.auth, menu);
        return true;
    }

    public void proc_Login(View v)
    {

        for (int i=0; i<5; i++)
            mClient.Send("asaadsasdasd");
    }

}

问题：仅从客户端（C# 服务器，没有任何错误）接收到一条消息，并且不会发送下一条消息。

Answer 1

此代码有效。我必须添加一个简单的按钮来触发 proc_Login 调用，我用

进行了测试

netcat -l -p 8546

在我的服务器（debian）上，每次按下按钮时，我都会得到 5 个“asaadsasdasd”。 （我使用了 8546 端口，因为它已经在我的防火墙上打开了）。

我当然加了

在 AndroidManifest.xml 文件中。

也许你的服务器代码在收到一行后关闭了套接字。

还请注意，您不需要线程，AsyncTask 会更合适，尽管对于示例它可以工作。

MainActivity.java：

package com.defranoux.testtcpsend;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {

  private CClient mClient;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mClient = new CClient();                
    Thread myThready = new Thread(mClient);
    myThready.start();

    Button button1 = (Button) findViewById(R.id.button1);
    button1.setOnClickListener(new OnClickListener() {

      @Override
      public void onClick(View arg0) {
        proc_Login(arg0);        
      }
    });    
  }


  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
  }

  public void proc_Login(View v)
  {
      for (int i=0; i<5; i++)
          mClient.Send("asaadsasdasd");
  }

}

CClient.java：

package com.defranoux.testtcpsend;

import java.io.*;
import java.net.Socket;
import java.net.UnknownHostException;

public class CClient    
implements Runnable     
{
    private Socket socket;
    private String ServerIP = "<my server ip goes here>";
    private static final int ServerPort = 8546;

    @Override
    public void run()
    {
        try 
        {
            socket = new Socket(ServerIP, ServerPort);
        }
        catch(Exception e) 
        {
            System.out.print("Whoops! It didn't work!:");
            System.out.print(e.getLocalizedMessage());
            System.out.print("\n");
        }
    }

    public void Send(String s)
    {
        try
        {
            PrintWriter outToServer = new PrintWriter(
                new OutputStreamWriter(
                    socket.getOutputStream()));
            outToServer.print(s + "\n");
            outToServer.flush();


        }
        catch (UnknownHostException e) {
            System.out.print(e.toString());
        } catch (IOException e) {
            System.out.print(e.toString());
        }catch (Exception e) {
            System.out.print(e.toString());
        }

    }
}

Answer 2

您永远不会清理与服务器的连接。刷新流后，您需要关闭这些输出流。

outToServer.flush();
outToServer.close();