android中下载文件类

package cn.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;

/**
 * 文件下载器 FileDownloader loader = new FileDownloader(context,
 * "http://browse.babasport.com/ejb3/ActivePort.exe", new
 * File("D:\\androidsoft\\test"), 2); loader.getFileSize();//得到文件总大小 try {
 * loader.download(new DownloadProgressListener(){ public void
 * onDownloadSize(int size) { print("已经下载:"+ size); } }); } catch (Exception e)
 * { e.printStackTrace(); }
 */
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度 */
    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;
    }

    /**
     * 更新指定线程最后下载的位置
     * 
     * @param threadId
     *            线程id
     * @param pos
     *            最后下载的位置
     */
    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
     *            文件保存目录
     * @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())// 判断文件夹是否存在
            {
                fileSaveDir.mkdirs();
            }
            this.threads = new DownloadThread[threadNum];// 创建线程数组
            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();// 根据响应获取文件大小
                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.getData(downloadUrl);// 获取下载记录
                if (logdata.size() > 0)
                {// 如果存在下载记录
                    for (Map.Entry<Integer, Integer> entry : logdata.entrySet())
                        data.put(entry.getKey(), entry.getValue());// 把各条线程已经下载的数据长度放入data中
                }
                if (this.data.size() == this.threads.length)
                {// 下面计算所有线程已经下载的数据长度
                    for (int i = 0; i < this.threads.length; i++)
                    {
                        this.downloadSize += this.data.get(i + 1);
                    }
                    print("已经下载的长度" + this.downloadSize);
                }
                // 计算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
     */
    private String getFileName(HttpURLConnection conn)
    {
        String filename = this.downloadUrl.substring(this.downloadUrl.lastIndexOf('/') + 1);
        if (filename == null || "".equals(filename.trim()))
        {// 如果获取不到文件名称
            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";// 默认取一个文件名
        }
        return filename;
    }

    /**
     * 开始下载文件
     * 
     * @param listener
     *            监听下载数量的变化,如果不需要了解实时下载的数量,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);// 初始化每条线程已经下载的数据长度为0
                }
            }
            for (int i = 0; i < this.threads.length; i++)
            {// 开启线程进行下载
                int downLength = this.data.get(i + 1);
                if (downLength < this.block && this.downloadSize < this.fileSize)
                {// 判断线程是否已经完成下载,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;// 下载未完成
            while (notFinish)
            {// 循环判断所有线程是否完成下载
                Thread.sleep(900);
                notFinish = false;// 假定全部线程下载完成
                for (int i = 0; i < this.threads.length; i++)
                {
                    if (this.threads[i] != null && !this.threads[i].isFinish())
                    {// 如果发现线程未完成下载
                        notFinish = true;// 设置标志为下载没有完成
                        if (this.threads[i].getDownLength() == -1)
                        {// 如果下载失败,再重新下载
                            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);// 通知目前已经下载完成的数据长度
            }
            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;
    }

    /**
     * 打印日志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());
        }
    }

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

 

package cn.service;

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

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

	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件长度
	 * @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文件长度
	 * @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,删除对应的下载记录
	 * @param path
	 */
	public void delete(String path){
		SQLiteDatabase db = openHelper.getWritableDatabase();
		db.execSQL("delete from filedownlog where downpath=?", new Object[]{path});
		db.close();
	}
	
}

  

package cn.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;
    /* 下载开始位置  */
    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;//开始位置
                int endPos = block * threadId -1;//结束位置
                http.setRequestProperty("Range", "bytes=" + startPos + "-"+ endPos);//设置获取实体数据的范围
                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);
    }
    /**
     * 下载是否完成
     * @return
     */
    public boolean isFinish() {
        return finish;
    }
    /**
     * 已经下载的内容大小
     * @return 如果返回值为-1,代表下载失败
     */
    public long getDownLength() {
        return downLength;
    }
}

 

posted on 2012-07-25 22:59  larryle  阅读(671)  评论(0)    收藏  举报