Android常用的工具类

jopen 12年前

一、检查网络是否可用

import android.app.AlertDialog;  import android.content.Context;  import android.content.DialogInterface;  import android.net.ConnectivityManager;  import android.net.NetworkInfo;      public class ConnectionUtil {  /**  * 检查网络是否可用  * @param context 应用程序的上下文对象  * @return  */  public static boolean isNetworkAvailable(Context context) {  ConnectivityManager connectivity = (ConnectivityManager) context  .getSystemService(Context.CONNECTIVITY_SERVICE); //获取系统网络连接管理器  if (connectivity == null) { //如果网络管理器为null  return false; //返回false表明网络无法连接  } else {  NetworkInfo[] info = connectivity.getAllNetworkInfo(); //获取所有的网络连接对象  if (info != null) { //网络信息不为null时  for (int i = 0; i < info.length; i++) { //遍历网路连接对象  if (info[i].isConnected()) { //当有一个网络连接对象连接上网络时  return true; //返回true表明网络连接正常  }  }  }  }  return false;  }    public static void httpTest(final Context ctx,String title,String msg) {  if (!isNetworkAvailable(ctx)) {  AlertDialog.Builder builders = new AlertDialog.Builder(ctx);  builders.setTitle(title);  builders.setMessage(msg);  builders.setPositiveButton(android.R.string.ok,  new DialogInterface.OnClickListener() {  public void onClick(DialogInterface dialog, int which) {  //alert.dismiss();  }  });  AlertDialog alert = builders.create();  alert.show();  }  }    }

二、读取流文件

StreamTool.java    import java.io.ByteArrayOutputStream;  import java.io.File;  import java.io.FileOutputStream;  import java.io.IOException;  import java.io.InputStream;  import java.io.PushbackInputStream;      public class StreamTool {      public static void save(File file, byte[] data) throws Exception {  FileOutputStream outStream = new FileOutputStream(file);  outStream.write(data);  outStream.close();  }     public static String readLine(PushbackInputStream in) throws IOException {  char buf[] = new char[128];  int room = buf.length;  int offset = 0;  int c;  loop: while (true) {  switch (c = in.read()) {  case -1:  case '\n':  break loop;  case '\r':  int c2 = in.read();  if ((c2 != '\n') && (c2 != -1)) in.unread(c2);  break loop;  default:  if (--room < 0) {  char[] lineBuffer = buf;  buf = new char[offset + 128];     room = buf.length - offset - 1;     System.arraycopy(lineBuffer, 0, buf, 0, offset);      }  buf[offset++] = (char) c;  break;  }  }  if ((c == -1) && (offset == 0)) return null;  return String.copyValueOf(buf, 0, offset);  }     /**  * 读取流  * @param inStream  * @return 字节数组  * @throws Exception  */  public static byte[] readStream(InputStream inStream) throws Exception{  ByteArrayOutputStream outSteam = new ByteArrayOutputStream();  byte[] buffer = new byte[1024];  int len = -1;  while( (len=inStream.read(buffer)) != -1){  outSteam.write(buffer, 0, len);  }  outSteam.close();  inStream.close();  return outSteam.toByteArray();  }  }

三、文件断点上传

MainActivity.java    import java.io.File;  import java.io.OutputStream;  import java.io.PushbackInputStream;  import java.io.RandomAccessFile;  import java.net.Socket;  import cn.itcast.service.UploadLogService;  import cn.itcast.utils.StreamTool;  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 MainActivity extends Activity {      private EditText filenameText;      private TextView resultView;      private ProgressBar uploadbar;      private UploadLogService service;      private Handler handler = new Handler(){  @Override  public void handleMessage(Message msg) {  uploadbar.setProgress(msg.getData().getInt("length"));  float num = (float)uploadbar.getProgress() / (float)uploadbar.getMax();  int result = (int)(num * 100);  resultView.setText(result + "%");  if(uploadbar.getProgress() == uploadbar.getMax()){  Toast.makeText(MainActivity.this, R.string.success, 1).show();  }  }      };            @Override      public void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          setContentView(R.layout.main);                    service =  new UploadLogService(this);          filenameText = (EditText)findViewById(R.id.filename);          resultView = (TextView)findViewById(R.id.result);          uploadbar = (ProgressBar)findViewById(R.id.uploadbar);          Button button = (Button)findViewById(R.id.button);          button.setOnClickListener(new View.OnClickListener() {  public void onClick(View v) {  String filename = filenameText.getText().toString();  if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){  File file = new File(Environment.getExternalStorageDirectory(), filename);  if(file.exists()){  uploadbar.setMax((int)file.length());  uploadFile(file);  }else{  Toast.makeText(MainActivity.this, R.string.notexsit, 1).show();  }  }else{  Toast.makeText(MainActivity.this, R.string.sdcarderror, 1).show();  }  }  });      }      private void uploadFile(final File file) {  new Thread(new Runnable() {  public void run() {  try {  String sourceid = service.getBindId(file);  Socket socket = new Socket("192.168.1.100", 7878);//根据IP地址和端口不同更改             OutputStream outStream = socket.getOutputStream();              String head = "Content-Length="+ file.length() + ";filename="+ file.getName()               + ";sourceid="+(sourceid!=null ? sourceid : "")+"\r\n";             outStream.write(head.getBytes());                          PushbackInputStream inStream = new PushbackInputStream(socket.getInputStream());  String response = StreamTool.readLine(inStream);             String[] items = response.split(";");  String responseSourceid = items[0].substring(items[0].indexOf("=")+1);  String position = items[1].substring(items[1].indexOf("=")+1);  if(sourceid==null){//如果是第一次上传文件,在数据库中不存在该文件所绑定的资源id,入库  service.save(responseSourceid, file);  }  RandomAccessFile fileOutStream = new RandomAccessFile(file, "r");  fileOutStream.seek(Integer.valueOf(position));  byte[] buffer = new byte[1024];  int len = -1;  int length = Integer.valueOf(position);  while( (len = fileOutStream.read(buffer)) != -1){  outStream.write(buffer, 0, len);  length += len;//累加已经上传的数据长度  Message msg = new Message();  msg.getData().putInt("length", length);  handler.sendMessage(msg);  }  if(length == file.length()) service.delete(file);  fileOutStream.close();  outStream.close();             inStream.close();             socket.close();         } catch (Exception e) {                              Toast.makeText(MainActivity.this, R.string.error, 1).show();         }  }  }).start();  }  }    DBOpenHelper.java//数据库    import android.content.Context;  import android.database.sqlite.SQLiteDatabase;  import android.database.sqlite.SQLiteOpenHelper;      public class DBOpenHelper extends SQLiteOpenHelper {      public DBOpenHelper(Context context) {  super(context, "itcast.db", null, 1);  }    @Override  public void onCreate(SQLiteDatabase db) {  db.execSQL("CREATE TABLE IF NOT EXISTS uploadlog (_id integer primary key autoincrement, path varchar(20), sourceid varchar(20))");  }    @Override  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {  // TODO Auto-generated method stub  }    }         UploadLogService.java      import java.io.File;  import android.content.Context;  import android.database.Cursor;  import android.database.sqlite.SQLiteDatabase;      public class UploadLogService {  private DBOpenHelper dbOpenHelper;    public UploadLogService(Context context){  dbOpenHelper = new DBOpenHelper(context);  }    public String getBindId(File file){  SQLiteDatabase db = dbOpenHelper.getReadableDatabase();  Cursor cursor = db.rawQuery("select sourceid from uploadlog where path=?", new String[]{file.getAbsolutePath()});  if(cursor.moveToFirst()){  return cursor.getString(0);  }  return null;  }    public void save(String sourceid, File file){  SQLiteDatabase db = dbOpenHelper.getWritableDatabase();  db.execSQL("insert into uploadlog(path,sourceid) values(?,?)",   new Object[]{file.getAbsolutePath(), sourceid});  }    public void delete(File file){  SQLiteDatabase db = dbOpenHelper.getWritableDatabase();  db.execSQL("delete from uploadlog where path=?", new Object[]{file.getAbsolutePath()});  }   }    四、多线程断点下载    MainActivity.java    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 MainActivity extends Activity {      private EditText pathText;      private TextView resultView;      private Button downloadButton;      private Button stopbutton;      private ProgressBar progressBar;      //hanlder的作用是用于往创建Hander对象所在的线程所绑定的消息队列发送消息      private Handler handler = new UIHander();            private final class UIHander extends Handler{  public void handleMessage(Message msg) {  switch (msg.what) {  case 1:  int size = msg.getData().getInt("size");  progressBar.setProgress(size);  float num = (float)progressBar.getProgress() / (float)progressBar.getMax();  int result = (int)(num * 100);  resultView.setText(result+ "%");  if(progressBar.getProgress() == progressBar.getMax()){  Toast.makeText(getApplicationContext(), R.string.success, 1).show();  }  break;      case -1:  Toast.makeText(getApplicationContext(), R.string.error, 1).show();  break;  }  }      }            @Override      public void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          setContentView(R.layout.main);                    pathText = (EditText) this.findViewById(R.id.path);          resultView = (TextView) this.findViewById(R.id.resultView);          downloadButton = (Button) this.findViewById(R.id.downloadbutton);          stopbutton = (Button) this.findViewById(R.id.stopbutton);          progressBar = (ProgressBar) this.findViewById(R.id.progressBar);          ButtonClickListener listener = new ButtonClickListener();          downloadButton.setOnClickListener(listener);          stopbutton.setOnClickListener(listener);      }            private final class ButtonClickListener implements View.OnClickListener{  public void onClick(View v) {  switch (v.getId()) {  case R.id.downloadbutton:  String path = pathText.getText().toString();  if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){  File saveDir = Environment.getExternalStorageDirectory();  download(path, saveDir);  }else{  Toast.makeText(getApplicationContext(), R.string.sdcarderror, 1).show();  }  downloadButton.setEnabled(false);  stopbutton.setEnabled(true);  break;      case R.id.stopbutton:  exit();  downloadButton.setEnabled(true);  stopbutton.setEnabled(false);  break;  }  }  /*  由于用户的输入事件(点击button, 触摸屏幕....)是由主线程负责处理的,如果主线程处于工作状态,  此时用户产生的输入事件如果没能在5秒内得到处理,系统就会报“应用无响应”错误。  所以在主线程里不能执行一件比较耗时的工作,否则会因主线程阻塞而无法处理用户的输入事件,  导致“应用无响应”错误的出现。耗时的工作应该在子线程里执行。  */  private DownloadTask task;  /**  * 退出下载  */  public void exit(){  if(task!=null) task.exit();  }  private void download(String path, File saveDir) {//运行在主线程  task = new DownloadTask(path, saveDir);  new Thread(task).start();  }      /*  * UI控件画面的重绘(更新)是由主线程负责处理的,如果在子线程中更新UI控件的值,更新后的值不会重绘到屏幕上  * 一定要在主线程里更新UI控件的值,这样才能在屏幕上显示出来,不能在子线程中更新UI控件的值  */  private final class DownloadTask implements Runnable{  private String path;  private File saveDir;  private FileDownloader loader;  public DownloadTask(String path, File saveDir) {  this.path = path;  this.saveDir = saveDir;  }  /**  * 退出下载  */  public void exit(){  if(loader!=null) loader.exit();  }    public void run() {  try {  loader = new FileDownloader(getApplicationContext(), path, saveDir, 3);  progressBar.setMax(loader.getFileSize());//设置进度条的最大刻度  loader.download(new DownloadProgressListener() {  public void onDownloadSize(int size) {  Message msg = new Message();  msg.what = 1;  msg.getData().putInt("size", size);  handler.sendMessage(msg);  }  });  } catch (Exception e) {  e.printStackTrace();  handler.sendMessage(handler.obtainMessage(-1));  }  }  }      }              }    DBOpenHelper.java    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    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, int threadId, int pos){  SQLiteDatabase db = openHelper.getWritableDatabase();  db.execSQL("update filedownlog set downlength=? where downpath=? and threadid=?",  new Object[]{pos, path, threadId});  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();  }    }    DownloadProgressListener.java    public interface DownloadProgressListener {  public void onDownloadSize(int size);  }    DownloadThread.java    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 (!downloader.getExit() && (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;  }  }    FileDownloader.java  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   *   try {  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  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;  /* 停止下载 */  private boolean exit;  /* 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;  }  /**  * 退出下载  */  public void exit(){  this.exit = true;  }  public boolean getExit(){  return this.exit;  }  /**  * 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, threadId, pos);  }  /**  * 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()) 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();//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总长度  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){//如果原先未曾下载或者原先的下载线程数与现在的线程数不一致  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  }  this.downloadSize = 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;  }  }  fileService.delete(this.downloadUrl);//如果存在下载记录,删除它们,然后重新添加  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  }  if(downloadSize == this.fileSize) fileService.delete(this.downloadUrl);//下载完成删除记录  } catch (Exception e) {  print(e.toString());  throw new Exception("file download error");  }  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());  }  }      private static void print(String msg){  Log.i(TAG, msg);  }  }