Question

我想从我的本地服务器使用手机下载视频并将其保存在SD卡上，但是Android客户端崩溃，我需要一些帮助。我使用了这段代码http://www.rgagnon.com/javadetails/java-0542.html

这是服务器代码：

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {

  public final static int SOCKET_PORT = 13267;  // you may change this
  public final static String FILE_TO_SEND = "d:/sintel.mp4";  // you may change this

  public static void main (String [] args ) throws IOException {
    FileInputStream fis = null;
    BufferedInputStream bis = null;
    OutputStream os = null;
    ServerSocket servsock = null;
    Socket sock = null;
    try {
      servsock = new ServerSocket(SOCKET_PORT);
      while (true) {
        System.out.println("Waiting...");
        try {
          sock = servsock.accept();
          System.out.println("Accepted connection : " + sock);
          // send file
          File myFile = new File (FILE_TO_SEND);
          byte [] mybytearray  = new byte [(int)myFile.length()];
          fis = new FileInputStream(myFile);
          bis = new BufferedInputStream(fis);
          bis.read(mybytearray,0,mybytearray.length);
          os = sock.getOutputStream();
          System.out.println("Sending " + FILE_TO_SEND + "(" + mybytearray.length + " bytes)");
          os.write(mybytearray,0,mybytearray.length);
          os.flush();
          System.out.println("Done.");
        }
        finally {
          if (bis != null) bis.close();
          if (os != null) os.close();
          if (sock!=null) sock.close();
        }
      }
    }
    finally {
      if (servsock != null) servsock.close();
    }
  }
}

客户代码：

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;


import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.Socket;




public class MainActivity extends ActionBarActivity {

    public final static int SOCKET_PORT = 13267;      // you may change this
    public final static String SERVER = "127.0.0.1";  // localhost
    public final static String FILE_TO_RECEIVED = "/storage/external_SD/sintel.mp4";;  // you may change this, I give a
    // different name because i don't want to
    // overwrite the one used by server...

    public final static int FILE_SIZE = 14000000; // file size temporary hard coded
    // should bigger than the file to be downloaded


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





    }



    public void buttonClicked(View view)throws IOException{

        int bytesRead;
        int current = 0;
        FileOutputStream fos = null;
        BufferedOutputStream bos = null;
        Socket sock = null;
        try {
            sock = new Socket(SERVER, SOCKET_PORT);
            System.out.println("Connecting...");

            // receive file
            byte [] mybytearray  = new byte [FILE_SIZE];
            InputStream is = sock.getInputStream();
            fos = new FileOutputStream(FILE_TO_RECEIVED);
            bos = new BufferedOutputStream(fos);
            bytesRead = is.read(mybytearray,0,mybytearray.length);
            current = bytesRead;

            do {
                bytesRead =
                        is.read(mybytearray, current, (mybytearray.length-current));
                if(bytesRead >= 0) current += bytesRead;
            } while(bytesRead > -1);

            bos.write(mybytearray, 0 , current);
            bos.flush();
            // System.out.println("File " + FILE_TO_RECEIVED
            //       + " downloaded (" + current + " bytes read)");
        }
        finally {
            if (fos != null) fos.close();
            if (bos != null) bos.close();
            if (sock != null) sock.close();
        }

    }


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

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

的xml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="download video"
        android:id="@+id/bdownload"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="199dp"
        android:onClick="buttonClicked"
        android:nestedScrollingEnabled="false" />
</RelativeLayout>

和清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.aidan.client" >

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Answer 1

您正在UI thread中执行大量网络任务，导致您的应用崩溃.... 将您的buttonClicked代码放在后台主题

中

public void buttonClicked(View view)throws IOException{
    new Thread(new Runnable() {
        @Override
        public void run() {
            int bytesRead;
    int current = 0;
    FileOutputStream fos = null;
    BufferedOutputStream bos = null;
    Socket sock = null;
    try {
        sock = new Socket(SERVER, SOCKET_PORT);
        System.out.println("Connecting...");

        // receive file
        byte [] mybytearray  = new byte [FILE_SIZE];
        InputStream is = sock.getInputStream();
        fos = new FileOutputStream(FILE_TO_RECEIVED);
        bos = new BufferedOutputStream(fos);
        bytesRead = is.read(mybytearray,0,mybytearray.length);
        current = bytesRead;

        do {
            bytesRead =
                    is.read(mybytearray, current, (mybytearray.length-current));
            if(bytesRead >= 0) current += bytesRead;
        } while(bytesRead > -1);

        bos.write(mybytearray, 0 , current);
        bos.flush();
        // System.out.println("File " + FILE_TO_RECEIVED
        //       + " downloaded (" + current + " bytes read)");
    }
    finally {
        if (fos != null) fos.close();
        if (bos != null) bos.close();
        if (sock != null) sock.close();
    }       
        }
    }).start();
}

Answer 2

您可以使用Android自己的DownloadManager安装程序来提供自己的实现。

它还将为您提供导航抽屉的进度，这将消除您的大量头痛。

Android从服务器下载视频

2 个答案: