sqlite[转]Android实现网络多线程断点续传下载

DownloadProgressListener中代码:

import com.android.network.DownloadProgressListener;
import com.android.network.FileDownloader;

import java.io.File;

 

 

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

  (2)依照文件长度和线程数统计每条线程下载的数码长度和下载地方。

<resources>
    <string name=”hello”>Hello World, MainActivity!</string>
    <string name=”app_name”>Android网络多线程断点下载</string>
    <string name=”path”>下载路径</string>
    <string name=”downloadbutton”>下载</string>
    <string name=”sdcarderror”>SDCard不设有或者写吝惜</string>
    <string name=”success”>下载完成</string>
    <string name=”error”>下载失利</string>
</resources>

 

 

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

 

sqlite,  (1)第一取得下载文件的尺寸,然后设置本地文件的尺寸。

sqlite 1)

 

        如:指定从文件的2M岗位上马下载,下载到地方(4M-1byte)结束

  程序结构如下图所示:

<manifest xmlns:android=”http://schemas.android.com/apk/res/android”      package=”com.android.downloader”      android:versionCode=”1″      android:versionName=”1.0″>
    <uses-sdk android:minSdkVersion=”8″ />

        @Override
        public void handleMessage(Message msg) {            
            switch (msg.what) {
            case 1:                
                progressBar.setProgress(msg.getData().getInt(“size”));
                float num = (float)progressBar.getProgress()/(float)progressBar.getMax();
                int result = (int)(num*100);
                resultView.setText(result+ “%”);
                
                if(progressBar.getProgress()==progressBar.getMax()){
                    Toast.makeText(MainActivity.this, R.string.success, 1).show();
                }
                break;
            case -1:
                Toast.makeText(MainActivity.this, R.string.error, 1).show();
                break;
            }
        }
    };
    
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        downloadpathText = (EditText) this.findViewById(R.id.path);
        progressBar = (ProgressBar) this.findViewById(R.id.downloadbar);
        resultView = (TextView) this.findViewById(R.id.resultView);
        Button button = (Button) this.findViewById(R.id.button);
        
        button.setOnClickListener(new View.OnClickListener() {
            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String path = downloadpathText.getText().toString();
                System.out.println(Environment.getExternalStorageState()+”——“+Environment.MEDIA_MOUNTED);
                
                if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
                    download(path, Environment.getExternalStorageDirectory());
                }else{
                    Toast.makeText(MainActivity.this, R.string.sdcarderror, 1).show();
                }
            }
        });
    }
    
      /**
       * 主线程(UI线程)
       * 对于展现控件的界面更新只是由UI线程负责,假若是在非UI线程更新控件的属性值,更新后的呈现界面不会呈现到屏幕上
       * @param path
       * @param savedir
       */
    private void download(final String path, final File savedir) {
        new Thread(new Runnable() {            
            @Override
            public void run() {
                FileDownloader loader = new FileDownloader(MainActivity.this, path, savedir, 3);
                progressBar.setMax(loader.getFileSize());//设置进度条的最大刻度为文件的长短
                
                try {
                    loader.download(new DownloadProgressListener() {
                        @Override
                        public void onDownloadSize(int size) {//实时获知文件已经下载的多长
                            Message msg = new Message();
                            msg.what = 1;
                            msg.getData().putInt(“size”, size);
                            handler.sendMessage(msg);//发送信息
                        }
                    });
                } catch (Exception e) {
                    handler.obtainMessage(-1).sendToTarget();
                }
            }
        }).start();
    }

 

    </application>
    
    <!– 在SDCard中开创与删除文件权限 –>
    <uses-permission android:name=”android.permission.MOUNT_UNMOUNT_FILESYSTEMS”/>
    
    <!– 往SDCard写入数据权限 –>
    <uses-permission android:name=”android.permission.WRITE_EXTERNAL_STORAGE”/>
    
    <!– 访问internet权限 –>
    <uses-permission android:name=”android.permission.INTERNET”/>

sqlite 2)

2.支撑断点。

 

package com.android.network;

public class FileService {
    private DBOpenHelper openHelper;

    
  file.setLength(filesize);//设置本地文件的尺寸

sqlite 3)

android:layout_width=”fill_parent”    

    public FileService(Context context) {
        openHelper = new DBOpenHelper(context);
    }
    
    /**
     * 获取每条线程已经下载的文件长度
     * @param path
     * @return
     */
    public Map<Integer, Integer> getData(String path){
        SQLiteDatabase db = openHelper.getReadableDatabase();
        Cursor cursor = db.rawQuery(“select threadid, downlength from filedownlog where downpath=?”, new String[]{path});
        Map<Integer, Integer> data = new HashMap<Integer, Integer>();
        
        while(cursor.moveToNext()){
            data.put(cursor.getInt(0), cursor.getInt(1));
        }
        
        cursor.close();
        db.close();
        return data;
    }
    
    /**
     * 保存每条线程已经下载的文书长度
     * @param path
     * @param map
     */
    public void save(String path,  Map<Integer, Integer> map){//int threadid, int position
        SQLiteDatabase db = openHelper.getWritableDatabase();
        db.beginTransaction();
        
        try{
            for(Map.Entry<Integer, Integer> entry : map.entrySet()){
                db.execSQL(“insert into filedownlog(downpath, threadid, downlength) values(?,?,?)”,
                        new Object[]{path, entry.getKey(), entry.getValue()});
            }
            db.setTransactionSuccessful();
        }finally{
            db.endTransaction();
        }
        
        db.close();
    }
    
    /**
     * 实时更新每条线程已经下载的公文长度
     * @param path
     * @param map
     */
    public void update(String path, Map<Integer, Integer> map){
        SQLiteDatabase db = openHelper.getWritableDatabase();
        db.beginTransaction();
        
        try{
            for(Map.Entry<Integer, Integer> entry : map.entrySet()){
                db.execSQL(“update filedownlog set downlength=? where downpath=? and threadid=?”,
                        new Object[]{entry.getValue(), path, entry.getKey()});
            }
            
            db.setTransactionSuccessful();
        }finally{
            db.endTransaction();
        }
        
        db.close();
    }
    
    /**
     * 当文件下载完成后,删除相应的下载记录
     * @param path
     */
    public void delete(String path){
        SQLiteDatabase db = openHelper.getWritableDatabase();
        db.execSQL(“delete from filedownlog where downpath=?”, new Object[]{path});
        db.close();
    }

       
下载截至地方:(线程id+1)*每条线程下载的多寡长度-1=?

sqlite 4)

 

   例如10M分寸,使用3个线程来下载,

<LinearLayout xmlns:android=”http://schemas.android.com/apk/res/android

  (3)使用Http的Range头字段指定每条线程从文件的什么岗位上马下载,下载到什么职位停止,

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL(“DROP TABLE IF EXISTS filedownlog”);
        onCreate(db);
    }
}

sqlite 5)

package com.android.service;

 

</manifest>  

AndroidManifest.xml文件中代码:

        线程下载的数目长度   (10%3 == 0 ?
10/3:10/3+1) ,第1,2个线程下载长度是4M,第六个线程下载长度为2M

package com.android.network;

 

 

FileDownloader中代码:

sqlite 6)

DownloadThread 中代码:

public class DBOpenHelper extends SQLiteOpenHelper {
    private static final String DBNAME = “down.db”;
    private static final int VERSION = 1;
    
    public DBOpenHelper(Context context) {
        super(context, DBNAME, null, VERSION);
    }
    
    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(“CREATE TABLE IF NOT EXISTS filedownlog (id integer primary key autoincrement, downpath varchar(100), threadid INTEGER, downlength INTEGER)”);
    }

     如:文件的长度为6M,线程数为3,那么,每条线程下载的数目长度为2M,每条线程先河下载的岗位如下图所示。

sqlite 7)

    private static void print(String msg){
        Log.i(TAG, msg);
    }

     HttpURLConnection.getContentLength();//获取下载文件的长短

末段,希望转载的心上人可以重视作者的劳动成果,加上转载地址:http://www.cnblogs.com/hanyonglu/archive/2012/02/20/2358801.html 谢谢。 

 

threadfile.seek(2097152);//从文件的哪些岗位上马写入数据

 

**

 

import com.android.service.FileService;

 
 string.xml文件中代码:

          
代码如下:HttpURLConnection.setRequestProperty(“Range”,
“bytes=2097152-4194303”);

DBOpenHelper中代码:

<?xml version=”1.0″ encoding=”utf-8″?> 

 

import android.content.Context;
import android.util.Log;

 

sqlite 8)

FileService中代码:

**本示例介绍在Android平台下通过HTTP协议落实断点续传下载。

import java.io.File;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class FileDownloader {
    private static final String TAG = “FileDownloader”;
    private Context context;
    private FileService fileService;    
    
    /* 已下载文件长度 */
    private int downloadSize = 0;
    
    /* 原始文件长度 */
    private int fileSize = 0;
    
    /* 线程数 */
    private DownloadThread[] threads;
    
    /* 本地保存文件 */
    private File saveFile;
    
    /* 缓存各线程下载的长短*/
    private Map<Integer, Integer> data = new ConcurrentHashMap<Integer, Integer>();
    
    /* 每条线程下载的长度 */
    private int block;
    
    /* 下载路径  */
    private String downloadUrl;
    
    /**
     * 获取线程数
     */
    public int getThreadSize() {
        return threads.length;
    }
    
    /**
     * 获取文件大小
     * @return
     */
    public int getFileSize() {
        return fileSize;
    }
    
    /**
     * 累计已下载大小
     * @param size
     */
    protected synchronized void append(int size) {
        downloadSize += size;
    }
    
    /**
     * 更新指定线程最终下载的岗位
     * @param threadId 线程id
     * @param pos 最终下载的职位
     */
    protected synchronized void update(int threadId, int pos) {
        this.data.put(threadId, pos);
        this.fileService.update(this.downloadUrl, this.data);
    }
    
    /**
     * 构建文件下载器
     * @param downloadUrl 下载路径
     * @param fileSaveDir 文件保留目录
     * @param threadNum 下载线程数
     */
    public FileDownloader(Context context, String downloadUrl, File fileSaveDir, int threadNum) {
        try {
            this.context = context;
            this.downloadUrl = downloadUrl;
            fileService = new FileService(this.context);
            URL url = new URL(this.downloadUrl);
            if(!fileSaveDir.exists()) fileSaveDir.mkdirs();
            this.threads = new DownloadThread[threadNum];                    
            
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setConnectTimeout(5*1000);
            conn.setRequestMethod(“GET”);
            conn.setRequestProperty(“Accept”, “image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*”);
            conn.setRequestProperty(“Accept-Language”, “zh-CN”);
            conn.setRequestProperty(“Referer”, downloadUrl); 
            conn.setRequestProperty(“Charset”, “UTF-8”);
            conn.setRequestProperty(“User-Agent”, “Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)”);
            conn.setRequestProperty(“Connection”, “Keep-Alive”);
            conn.connect();
            printResponseHeader(conn);
            
            if (conn.getResponseCode()==200) {
                this.fileSize = conn.getContentLength();//按照响应获取文件大小
                if (this.fileSize <= 0) throw new RuntimeException(“Unkown file size “);
                        
                String filename = getFileName(conn);//获取文件名称
                this.saveFile = new File(fileSaveDir, filename);//构建保存文件
                Map<Integer, Integer> logdata = fileService(Service).getData(downloadUrl);//获取下载记录
                
                if(logdata.size()>0){//即便存在下载记录
                    for(Map.Entry<Integer, Integer> entry : logdata.entrySet())
                        data.put(entry.getKey(), entry.getValue());//把各条线程已经下载的多长放入data中
                }
                
                if(this.data.size()==this.threads.length){//下面总结有所线程已经下载的数目长度
                    for (int i = 0; i < this.threads.length; i++) {
                        this.downloadSize += this.data.get(i+1);
                    }
                    
                    print(“已经下载的尺寸”+ this.downloadSize);
                }
                
                //总计每条线程下载的数据长度
                this.block = (this.fileSize % this.threads.length)==0? this.fileSize / this.threads.length : this.fileSize / this.threads.length + 1;
            }else{
                throw new RuntimeException(“server no response “);
            }
        } catch (Exception e) {
            print(e.toString());
            throw new RuntimeException(“don’t connection this url”);
        }
    }
    
    /**
     * 获取文件名
     * @param conn
     * @return
     */
    private String getFileName(HttpURLConnection conn) {
        String filename = this.downloadUrl.substring(this.downloadUrl.lastIndexOf(‘/’) + 1);
        
        if(filename==null || “”.equals(filename.trim())){//即使拿到不到文件名称
            for (int i = 0;; i++) {
                String mine = conn.getHeaderField(i);
                
                if (mine == null) break;
                
                if(“content-disposition”.equals(conn.getHeaderFieldKey(i).toLowerCase())){
                    Matcher m = Pattern.compile(“.*filename=(.*)”).matcher(mine.toLowerCase());
                    if(m.find()) return m.group(1);
                }
            }
            
            filename = UUID.randomUUID()+ “.tmp”;//默认取一个文书名
        }
        
        return filename;
    }
    
    /**
     *  开首下载文件
     * @param listener 监听下载数量的转移,假如不需要通晓实时下载的多少,可以设置为null
     * @return 已下载文件大小
     * @throws Exception
     */
    public int download(DownloadProgressListener listener) throws Exception{
        try {
            RandomAccessFile randOut = new RandomAccessFile(this.saveFile, “rw”);
            if(this.fileSize>0) randOut.setLength(this.fileSize);
            randOut.close();
            URL url = new URL(this.downloadUrl);
            
            if(this.data.size() != this.threads.length){
                this.data.clear();
                
                for (int i = 0; i < this.threads.length; i++) {
                    this.data.put(i+1, 0);//起头化每条线程已经下载的数码长度为0
                }
            }
            
            for (int i = 0; i < this.threads.length; i++) {//开启线程举行下载
                int downLength = this.data.get(i+1);
                
                if(downLength < this.block && this.downloadSize<this.fileSize){//判断线程是否业已成功下载,否则继续下载    
                    this.threads[i] = new DownloadThread(this, url, this.saveFile, this.block, this.data.get(i+1), i+1);
                    this.threads[i].setPriority(7);
                    this.threads[i].start();
                }else{
                    this.threads[i] = null;
                }
            }
            
            this.fileService.save(this.downloadUrl, this.data);
            boolean notFinish = true;//下载未到位
            
            while (notFinish) {// 循环判断所有线程是否成功下载
                Thread.sleep(900);
                notFinish = false;//假定全体线程下载完成
                
                for (int i = 0; i < this.threads.length; i++){
                    if (this.threads[i] != null && !this.threads[i].isFinish()) {//假使发现线程未形成下载
                        notFinish = true;//设置标志为下载没有做到
                        
                        if(this.threads[i].getDownLength() == -1){//如果下载败北,再另行下载
                            this.threads[i] = new DownloadThread(this, url, this.saveFile, this.block, this.data.get(i+1), i+1);
                            this.threads[i].setPriority(7);
                            this.threads[i].start();
                        }
                    }
                }    
                
                if(listener!=null) listener.onDownloadSize(this.downloadSize);//公告最近儿早上就下载完成的多寡长度
            }
            
            fileService.delete(this.downloadUrl);
        } catch (Exception e) {
            print(e.toString());
            throw new Exception(“file download fail”);
        }
        return this.downloadSize;
    }
    
    /**
     * 获取Http响应头字段
     * @param http
     * @return
     */
    public static Map<String, String> getHttpResponseHeader(HttpURLConnection http) {
        Map<String, String> header = new LinkedHashMap<String, String>();
        
        for (int i = 0;; i++) {
            String mine = http.getHeaderField(i);
            if (mine == null) break;
            header.put(http.getHeaderFieldKey(i), mine);
        }
        
        return header;
    }
    
    /**
     * 打印Http头字段
     * @param http
     */
    public static void printResponseHeader(HttpURLConnection http){
        Map<String, String> header = getHttpResponseHeader(http);
        
        for(Map.Entry<String, String> entry : header.entrySet()){
            String key = entry.getKey()!=null ? entry.getKey()+ “:” : “”;
            print(key+ entry.getValue());
        }
    }

以身作则源码:点击下载 

import java.util.HashMap;
import java.util.Map;

sqlite 9 

sqlite 10)

sqlite 11)

我们编辑的是Andorid的HTTP协议多线程断点下载应用程序。直接采用单线程下载HTTP文件对大家来说是一件万分简单的事。那么,多线程断点需要如何效益?

sqlite 12)

package com.android.downloader;

 
运作效果如下

android:orientation=”vertical”   

    <application android:icon=”@drawable/icon” android:label=”@string/app_name”>
        <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>

RandomAccessFile threadfile =
new RandomAccessFile(“QQWubiSetup.exe “,”rwd”);

  
 RandomAccessFile file = new
RandomAccessFile(“QQWubiSetup.exe”,”rwd”);

sqlite 13)

 

 

 

import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

 

<?xml version=”1.0″ encoding=”utf-8″?>

sqlite 14)

sqlite 15)

sqlite 16)

 sqlite 17

    <!– 下载路径 –>
    <TextView
        android:layout_width=”fill_parent”
        android:layout_height=”wrap_content”
        android:text=”@string/path”/>
    <EditText 
        android:id=”@+id/path” 
        android:text=”http://www.winrar.com.cn/download/wrar380sc.exe” 
        android:layout_width=”fill_parent” 
        android:layout_height=”wrap_content”>
    </EditText>
    <!– 下载按钮 –>
    <Button
        android:layout_width=”wrap_content”
        android:layout_height=”wrap_content”
        android:text=”@string/downloadbutton”
        android:id=”@+id/button”/>
    <!– 进度条 –>
    <ProgressBar
        android:layout_width=”fill_parent”
        android:layout_height=”20dip”
        style=”?android:attr/progressBarStyleHorizontal”
        android:id=”@+id/downloadbar” />
    <TextView
        android:layout_width=”fill_parent”
        android:layout_height=”wrap_content”
        android:gravity=”center”
        android:id=”@+id/resultView” />
    </LinearLayout>


 MainActivity中代码:

}  

        下载开首地方:线程id*每条线程下载的数据长度
= ?

public class DownloadThread extends Thread {
    private static final String TAG = “DownloadThread”;
    private File saveFile;
    private URL downUrl;
    private int block;
    
    /* 下载起首地方  */
    private int threadId = -1;    
    private int downLength;
    private boolean finish = false;
    private FileDownloader downloader;
    
    public DownloadThread(FileDownloader downloader, URL downUrl, File saveFile, int block, int downLength, int threadId) {
        this.downUrl = downUrl;
        this.saveFile = saveFile;
        this.block = block;
        this.downloader = downloader;
        this.threadId = threadId;
        this.downLength = downLength;
    }
    
    @Override
    public void run() {
        if(downLength < block){//未下载完成
            try {
                HttpURLConnection http = (HttpURLConnection) downUrl.openConnection();
                http.setConnectTimeout(5 * 1000);
                http.setRequestMethod(“GET”);
                http.setRequestProperty(“Accept”, “image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*”);
                http.setRequestProperty(“Accept-Language”, “zh-CN”);
                http.setRequestProperty(“Referer”, downUrl.toString()); 
                http.setRequestProperty(“Charset”, “UTF-8”);
                int startPos = block * (threadId – 1) + downLength;//起始位置
                int endPos = block * threadId -1;//截止地点
                http.setRequestProperty(“Range”, “bytes=” + startPos + “-“+ endPos);//设置获取实体数据的限制
                http.setRequestProperty(“User-Agent”, “Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)”);
                http.setRequestProperty(“Connection”, “Keep-Alive”);
                
                InputStream inStream = http.getInputStream();
                byte[] buffer = new byte[1024];
                int offset = 0;
                print(“Thread ” + this.threadId + ” start download from position “+ startPos);
                RandomAccessFile threadfile = new RandomAccessFile(this.saveFile, “rwd”);
                threadfile.seek(startPos);
                
                while ((offset = inStream.read(buffer, 0, 1024)) != -1) {
                    threadfile.write(buffer, 0, offset);
                    downLength += offset;
                    downloader.update(this.threadId, downLength);
                    downloader.append(offset);
                }
                
                threadfile.close();
                inStream.close();
                print(“Thread ” + this.threadId + ” download finish”);
                this.finish = true;
            } catch (Exception e) {
                this.downLength = -1;
                print(“Thread “+ this.threadId+ “:”+ e);
            }
        }
    }
    
    private static void print(String msg){
        Log.i(TAG, msg);
    }
    
    /**
     * 下载是否成功
     * @return
     */
    public boolean isFinish() {
        return finish;
    }
    
    /**
     * 已经下载的情节大小
     * @return 倘使重回值为-1,代表下载失利
     */
    public long getDownLength() {
        return downLength;
    }

 

1.多线程下载,

应用多线程的裨益:使用多线程下载会提升文件下载的速度。那么多线程下载文件的长河是: 

import android.util.Log;

import java.io.File;
import java.io.InputStream;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.URL;

package com.android.network;

public class MainActivity extends Activity {
    private EditText downloadpathText;
    private TextView resultView;
    private ProgressBar progressBar;
    
    /**
     * 当Handler被创设会波及到开创它的脚下线程的信息队列,该类用于往音信队列发送音信
     * 音讯队列中的音讯由近期线程内部开展处理
     */
    private Handler handler = new Handler(){

   

**  (4)保存文件,使用RandomAccessFile类指定每条线程从地点文件的哪些地点上马写入数据。**

  sqlite 18

android:layout_height=”fill_parent”>

sqlite 19)

本文转自:http://www.cnblogs.com/hanyonglu/archive/2012/02/20/2358801.html

}  

}  

package com.android.service;

 main.xml文件中代码:

public interface DownloadProgressListener {
    public void onDownloadSize(int size);

 

完毕。^_^ 

 <?xml version=”1.0″ encoding=”utf-8″?>    

网站地图xml地图