AndroidはHTTPプロトコルでブレークポイントの再ダウンロードを実現


 FileDownloader.java                                                                                                                 package cn.itcast.net.download;

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;
import cn.itcast.service.FileService;

import android.content.Context;
import android.util.Log;
/**
 *      
 * FileDownloader loader = new FileDownloader(context, "http://browse.babasport.com/ejb3/ActivePort.exe",
				new File("D:\\androidsoft\\test"), 2);
		loader.getFileSize();//       
		try {
			loader.download(new DownloadProgressListener(){
				public void onDownloadSize(int size) {
					print("    :"+ size);
				}			
			});
		} catch (Exception e) {
			e.printStackTrace();
		}
 */
public class FileDownloader {
	private static final String TAG = "FileDownloader";
	private Context context;
	private FileService fileService;	
	/*         */
	private int downloadSize = 0;
	/*        */
	private int fileSize = 0;
	/*     */
	private DownloadThread[] threads;
	/*        */
	private File saveFile;
	/*           */
	private Map<Integer, Integer> data = new ConcurrentHashMap<Integer, Integer>();
	/*           */
	private int block;
	/*       */
	private String downloadUrl;
	/**
	 *      
	 */
	public int getThreadSize() {
		return threads.length;
	}
	/**
	 *       
	 * @return
	 */
	public int getFileSize() {
		return fileSize;
	}
	/**
	 *        
	 * @param size
	 */
	protected synchronized void append(int size) {
		downloadSize += size;
	}
	/**
	 *              
	 * @param threadId   id
	 * @param pos        
	 */
	protected synchronized void update(int threadId, int pos) {
		this.data.put(threadId, pos);
		this.fileService.update(this.downloadUrl, this.data);
	}
	/**
	 *        
	 * @param downloadUrl     
	 * @param fileSaveDir       
	 * @param threadNum      
	 */
	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();//          
				if (this.fileSize <= 0) throw new RuntimeException("Unkown file size ");
						
				String filename = getFileName(conn);//      
				this.saveFile = new File(fileSaveDir, filename);//      
				Map<Integer, Integer> logdata = fileService.getData(downloadUrl);//      
				if(logdata.size()>0){//        
					for(Map.Entry<Integer, Integer> entry : logdata.entrySet())
						data.put(entry.getKey(), entry.getValue());//                data 
				}
				if(this.data.size()==this.threads.length){//                 
					for (int i = 0; i < this.threads.length; i++) {
						this.downloadSize += this.data.get(i+1);
					}
					print("       "+ this.downloadSize);
				}
				//             
				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");
		}
	}
	/**
	 *      
	 */
	private String getFileName(HttpURLConnection conn) {
		String filename = this.downloadUrl.substring(this.downloadUrl.lastIndexOf('/') + 1);
		if(filename==null || "".equals(filename.trim())){//          
			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";//        
		}
		return filename;
	}
	
	/**
	 *        
	 * @param listener          ,              ,     null
	 * @return        
	 * @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);//                 0
				}
			}
			for (int i = 0; i < this.threads.length; i++) {//        
				int downLength = this.data.get(i+1);
				if(downLength < this.block && this.downloadSize<this.fileSize){//            ,      	
					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;//     
			while (notFinish) {//               
				Thread.sleep(900);
				notFinish = false;//          
				for (int i = 0; i < this.threads.length; i++){
					if (this.threads[i] != null && !this.threads[i].isFinish()) {//           
						notFinish = true;//           
						if(this.threads[i].getDownLength() == -1){//      ,     
							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);//               
			}
			fileService.delete(this.downloadUrl);
		} catch (Exception e) {
			print(e.toString());
			throw new Exception("file download fail");
		}
		return this.downloadSize;
	}
	/**
	 *   Http     
	 * @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;
	}
	/**
	 *   Http   
	 * @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());
		}
	}

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

DownloadThread.java
package cn.itcast.net.download;

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

import android.util.Log;

public class DownloadThread extends Thread {
	private static final String TAG = "DownloadThread";
	private File saveFile;
	private URL downUrl;
	private int block;
	/*         */
	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){//     
			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;//    
				int endPos = block * threadId -1;//    
				http.setRequestProperty("Range", "bytes=" + startPos + "-"+ endPos);//           
				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);
	}
	/**
	 *       
	 * @return
	 */
	public boolean isFinish() {
		return finish;
	}
	/**
	 *          
	 * @return       -1,      
	 */
	public long getDownLength() {
		return downLength;
	}
}

DownloadProgressListener.java
package cn.itcast.net.download;

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

DBOpenHelper.java
package cn.itcast.service;

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

public class DBOpenHelper extends SQLiteOpenHelper {
	private static final String DBNAME = "itcast.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)");
	}

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

}

FileService.java
package cn.itcast.service;

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

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
/**
 *   bean
 *
 */
public class FileService {
	private DBOpenHelper openHelper;

	public FileService(Context context) {
		openHelper = new DBOpenHelper(context);
	}
	/**
	 *                
	 * @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;
	}
	/**
	 *                
	 * @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();
	}
	/**
	 *                  
	 * @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();
	}
	/**
	 *         ,         
	 * @param path
	 */
	public void delete(String path){
		SQLiteDatabase db = openHelper.getWritableDatabase();
		db.execSQL("delete from filedownlog where downpath=?", new Object[]{path});
		db.close();
	}
	
}

DownloadActivity.java
package cn.itcast.download;

import java.io.File;

import cn.itcast.net.download.DownloadProgressListener;
import cn.itcast.net.download.FileDownloader;

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;

public class DownloadActivity extends Activity {
    private EditText downloadpathText;
    private TextView resultView;
    private ProgressBar progressBar;
    // Handler                    ,             
    //                   
    private Handler handler = new Handler(){

		@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(DownloadActivity.this, R.string.success, 1).show();
				}
				break;

			case -1:
				Toast.makeText(DownloadActivity.this, R.string.error, 1).show();
				break;
			}
		}
    };
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        downloadpathText = (EditText) this.findViewById(R.id.downloadpath);
        progressBar = (ProgressBar) this.findViewById(R.id.downloadbar);
        resultView = (TextView) this.findViewById(R.id.result);
        Button button = (Button) this.findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {			
			@Override
			public void onClick(View v) {
				String path = downloadpathText.getText().toString();
				if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
					download(path, Environment.getExternalStorageDirectory());
				}else{
					Toast.makeText(DownloadActivity.this, R.string.sdcarderror, 1).show();
				}
				
			}
		});
    }
    //   (UI  )
    //      ,             
    //              UI    ,     UI          ,                
    private void download(final String path, final File savedir) {
    	new Thread(new Runnable() {			
			@Override
			public void run() {
				FileDownloader loader = new FileDownloader(DownloadActivity.this, path, savedir, 3);
		    	progressBar.setMax(loader.getFileSize());//                
				try {
					loader.download(new DownloadProgressListener() {
						@Override
						public void onDownloadSize(int size) {//               
							Message msg = new Message();
							msg.what = 1;
							msg.getData().putInt("size", size);
							handler.sendMessage(msg);//    
						}
					});
				} catch (Exception e) {
					handler.obtainMessage(-1).sendToTarget();
				}
			}
		}).start();
	}
}

プロジェクトソースのダウンロード