使用TCP

Question

我想用PC将图像从我的PC发送到Android手机。传输图像文件（文件大小匹配）。但是，无法读取图像。 我在Shartphone的PC和服务器端代码中编写了客户端代码。

如果你能告诉我问题在哪里，我将不胜感激。提前谢谢。

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

代码链接 https://drive.google.com/drive/folders/1MZz6FSWpFWgCyrvtTNXUakHTZll5n84n?usp=sharing

服务器端：智能手机接收图片

package com.example.an_server_img_receive;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.text.SimpleDateFormat;
import java.util.Date;

import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

public class MainActivity extends Activity 
{

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

        runThread1();
    }

    @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;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item)
    {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) 
        {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }



    /////////////////////////////// run
    /////////////////////////////// thread//////////////////////////////////////////////
    private void runThread1() // to receive image from server/laptop
    {

        new Thread() {

            public void run() 
            {
                Log.d("p2p", "1");

                    try {
                        /////////////////////
                        // System.out.println("aaa");
                        ServerSocket serverSocket = new ServerSocket(6000);
                        Socket clientSocket = serverSocket.accept();
                        String format = new SimpleDateFormat("yyyyMMddHHmmss", java.util.Locale.getDefault())
                                .format(new Date());

                        Log.d("p2p", "2");
                        Log.d("p2p", "2a"+ clientSocket.isConnected());


                        DataInputStream dis = new DataInputStream(clientSocket.getInputStream());
                        Log.d("p2p", "2b"+ clientSocket.getKeepAlive());




                        File f = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM)
                                + "/Camera/" + File.separator + format + ".jpg");
                        Log.d("p2p", "#" + Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM));
                        Log.d("p2p", "3");
                        f.createNewFile();


                        DataOutputStream dos = new DataOutputStream(new FileOutputStream(f));

                        Log.d("p2p", "4");

                        byte[] buffer = new byte[1024];
                        int len;

                        while ((len = dis.read(buffer)) != -1) 
                        {
                            dos.write(buffer, 0, len);
                        }

                        Log.d("p2p", "5");

                        dis.close();
                        dos.close();
                        serverSocket.close();

                        Log.d("p2p", "6");


                        runOnUiThread(new Runnable()
                        {

                            @Override
                            public void run() 
                            {
                                //tv1.setText("#" + i);
                                Toast.makeText(getApplicationContext(), "Image is received", Toast.LENGTH_LONG).show();
                            }
                        });
                        Thread.sleep(30);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }

        }.start();
    }
}

PC：发送图片

import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.Socket;


/*   CLIENT SEND AN IMAGE    */
public class myclienttcpimage 
{
    public static void main(String args[]) 
    {  
        try
        {
            Socket socket = new Socket("192.168.0.101", 6000);
            DataOutputStream out = new DataOutputStream(socket.getOutputStream());
            //out.writeChar('I'); // as image,
            DataInputStream dis = new DataInputStream(new FileInputStream("D:\\image.jpg"));
            ByteArrayOutputStream ao = new ByteArrayOutputStream();
            int read = 0;
            byte[] buf = new byte[1024];
            long start = System.nanoTime();
            while ((read = dis.read(buf)) > -1)
            {
                ao.write(buf, 0, read);
            }

            long end = System.nanoTime();
            long time = end-start;
            System.out.println("time " + time);

            System.out.println("c:" + ao.size());
            out.writeLong(ao.size());
            out.write(ao.toByteArray());
            out.flush();
            out.close();
            dis.close();
            socket.close();
        } 
        catch (IOException e) 
        {
            e.printStackTrace();
        }
    }

}