[android开发]小说下载软件

前言

今天闲来无事就将上个月写的一款小的app介绍一下吧，这款app是用来下载小说，小说来源是无限小说网，原理自然是直接扒掉了人家的html页面，然后从html源码里面寻找出来小说的下载地址，里面用到了三个开源库，一个是设置状态栏变色的（有bug，不太通用），另一个是下拉刷新的开源库，第三个解析xml的库jsoup（源代码在文末）

app效果图

源码介绍

下面简单介绍一下源码：

自定义进度条：
自定义进度条可以参考我前面的代码

http://blog.csdn.net/supervictim/article/details/53907393

我在这个基础上增加了自定义属性，用来设置旋转的进度条图片和文字，使用过程中变成了如下形式：

 <cn.karent.downloadtxt.UI.ProgressViewInResultandroid:id="@+id/result_progress"android:layout_centerInParent="true"android:layout_width="70dp"android:layout_height="70dp"wan:bitmap="@drawable/pic_dlg_loading"wan:text="载"/>

自定义属性需要在values文件夹中创建一个叫做attrs.xml的文件：

<resources><declare-styleable name="ProgressBitmap"><!--显示的是哪个背景图的id--><attr name="bitmap" format="reference"/><!--要绘制在中心的字符串--><attr name="text" format="string"/></declare-styleable></resources>

这样就可以在上面的使用了，下面搬上最终的进度条代码：

public class ProgressViewInResult extends View {private Bitmap mBitmap;private Matrix mMatrix;private int mCurrent = 0;private Progress mProgress;private boolean mContinue = true;private Paint mTextPaint;private String mText;public ProgressViewInResult(Context context) {super(context);init();}public ProgressViewInResult(Context context, AttributeSet attrs) {super(context, attrs);mTextPaint = new Paint();mTextPaint.setTextSize(ScreenUtil.dp2px(18));mTextPaint.setColor(Color.rgb(0xa6, 0xa6, 0xa6));//获取自定义属性TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.ProgressBitmap);if( typedArray != null) {int res = typedArray.getResourceId(R.styleable.ProgressBitmap_bitmap, R.drawable.abs__spinner_48_inner_holo);mBitmap = BitmapFactory.decodeResource(context.getResources(), res);mText = typedArray.getString(R.styleable.ProgressBitmap_text);} else {mBitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.abs__spinner_48_inner_holo);}init();}private void init() {mMatrix = new Matrix();mProgress = new Progress();//执行操作mProgress.execute();}public Bitmap getmBitmap() {return mBitmap;}public void setmBitmap(Bitmap mBitmap) {this.mBitmap = mBitmap;}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);mMatrix.setRotate( (mCurrent ++) * 6, mBitmap.getWidth() / 2, mBitmap.getHeight() / 2);//旋转之后将图片缩小mMatrix.postScale(0.7f, 0.7f);canvas.drawBitmap(mBitmap, mMatrix, null);//绘制文字if( mText == null)return;Paint.FontMetrics fontMetrics = mTextPaint.getFontMetrics();float strWidth = mTextPaint.measureText(mText);float y = mBitmap.getHeight() * 0.7f / 2;y += (Math.abs(fontMetrics.ascent) - fontMetrics.descent) / 2;float x = ( mBitmap.getWidth() * 0.7f - strWidth ) / 2;canvas.drawText(mText, x, y, mTextPaint);}public void setContinue(boolean c) {mContinue = c;}class Progress extends AsyncTask<Void, Void, Void> {@Overrideprotected void onProgressUpdate(Void... values) {super.onProgressUpdate(values);invalidate();}@Overrideprotected Void doInBackground(Void... params) {while( mContinue ) {try {Thread.sleep(50);} catch (Exception e) {e.printStackTrace();}publishProgress();}return null;}}
}

下载功能：创建了一个service（service的执行也是在UI线程里面）在后台下载。
DownloadService.java

public class DownloadService extends Service {private NotificationManager mNotifyManager;private DownloadBinder mBinder = new DownloadBinder();private NotificationCompat.Builder mBuilder;private Integer mLength = 0;private Handler mHandler = new Handler() {@Overridepublic void handleMessage(Message msg) {if( msg.what == 0x123) {int length = (Integer)msg.obj;mBuilder.setProgress(100, length, false);mBuilder.setContentText(length + "%");if( length != 100) {mBuilder.setContentInfo("正在下载...");} else {mBuilder.setContentInfo("下载完成!");}mNotifyManager.notify(0, mBuilder.build());}}};@Overridepublic void onCreate() {
Log.d("service", "onCreate....");mNotifyManager = (NotificationManager) getSystemService(Activity.NOTIFICATION_SERVICE);mBuilder = new NotificationCompat.Builder(this);mBuilder.setProgress(100,0,false).setSmallIcon(R.drawable.paper_flight).setContentInfo("下载中...").setContentTitle("正在下载");super.onCreate();}@Overridepublic int onStartCommand(Intent intent, int flags, int startId) {
Log.d("service", "onStartCommand.....");return super.onStartCommand(intent, flags, startId);}@Nullable@Overridepublic IBinder onBind(Intent intent) {return mBinder;}public class DownloadBinder extends Binder {public void startDownload(final String url,final String name) {if( url == null) {Toast.makeText(DownloadService.this, "sorry,下载地址没有找到！", Toast.LENGTH_SHORT).show();return;}new Thread(new Runnable() {@Overridepublic void run() {//开启事件循环，使线程能够显示UI提示Looper.prepare();//下载小说Http.downloadTxt(url, name, new RefreshListenerImpl());Looper.loop();}}).start();}}public class RefreshListenerImpl implements RefreshListener {@Overridepublic void refresh(int length) {Message msg = new Message();msg.what = 0x123;msg.obj = length;mHandler.sendMessage(msg);}@Overridepublic void finish() {}}}

Http.downloadTxt():

public static void downloadTxt(String url, String name, DownloadService.RefreshListenerImpl refresh) {String path = "/mnt/sdcard/小说下载/";String filePath = path + name + ".zip";try {File directory = new File(path);if( !directory.exists() )directory.mkdirs();File file = new File(filePath);if( !file.exists())file.createNewFile();FileOutputStream fos = new FileOutputStream(filePath);URL u = new URL(url);HttpURLConnection conn =  (HttpURLConnection) u.openConnection();conn.setRequestMethod("GET");conn.setRequestProperty("Charset", "UTF-8");conn.setDoInput(true);//禁止转发conn.setInstanceFollowRedirects(false);conn.connect();//获取转发后的真正地址String location = conn.getHeaderField("Location");//说明下载地址不存在if( location == null) {Toast.makeText(MyApplication.getContext(), "小说不存在！", Toast.LENGTH_SHORT).show();return;}//小米手机获取的中文地址是以ISO-8859-1为编码的，需要将其转换为utf8，否则找不到真正的下载地址
//            location = new String(location.getBytes("ISO-8859-1"), "utf8");
System.out.println("location:" + location);String url1 = StringUtil.encodeUrl(location);url1 += ".zip";
//System.out.println("url1:" + url1);URL u2 = new URL(url1);HttpURLConnection conn1 =(HttpURLConnection) u2.openConnection();InputStream is = conn1.getInputStream();//获取文件长度int fileLength = conn1.getContentLength();byte[] bytes = new byte[1024];int total = 0;int length = -1;int currentProgress = 0;int downloadPrecent = 0;while( (length = is.read(bytes)) != -1) {
//System.out.println("bytes:" + bytes);total += length;//更新进度//卡顿解决方案，当进度积累到一定量才更新，不要频繁调用更新currentProgress = total * 100 / fileLength;if( currentProgress - downloadPrecent >= 2) {refresh.refresh(currentProgress);downloadPrecent = currentProgress;}fos.write(bytes, 0, length);}is.close();fos.close();
System.out.println("下载完成...");} catch (Exception e) {e.printStackTrace();}}

在真正下载小说的时候我获取到了下载地址，点击之后会发现无限小说网的后台重定向了：

如上图，在获取到了访问地址之后返回的状态码是302，而真正的地址就藏在返回头的Location字段里面，所以下载的代码才需要获取Location字段进而进行真正的下载

          String location = conn.getHeaderField("Location");//说明下载地址不存在if( location == null) {Toast.makeText(MyApplication.getContext(), "小说不存在！", Toast.LENGTH_SHORT).show();return;}//小米手机获取的中文地址是以ISO-8859-1为编码的，需要将其转换为utf8，否则找不到真正的下载地址
//            location = new String(location.getBytes("ISO-8859-1"), "utf8");
System.out.println("location:" + location);String url1 = StringUtil.encodeUrl(location);url1 += ".zip";
//System.out.println("url1:" + url1);URL u2 = new URL(url1);HttpURLConnection conn1 =(HttpURLConnection) u2.openConnection();InputStream is = conn1.getInputStream();

获取Location字段还有一个问题，那就是Location字段里面确实是小说的地址，但是却含有中文，小米、vivo手机必须要将其再用ISO-8859-1才能使用，否则就会找不到地址，其他的华为、模拟器等就直接是utf8就行

最后

上面代码可用，但是不要用于商业用途，出了问题概不负责
源代码：点我下载