DownloadTask下載任務(wù)
public class DownloadTask extends AsyncTask<String,Integer,Integer> {
public static final int TYPE_SUCCESS=0;//成功
public static final int TYPE_FAILED=1;//失敗
public static final int TYPE_PAUSED=2;//暫停
public static final int TYPE_CANCELED=3;//取消
private DownloadListener listener;//下載監(jiān)聽器
private boolean isCanceled=false;//是否取消
private boolean isPaused=false;//是否暫停
private int lastprogress;//下載進度
public DownloadTask(DownloadListener listener){//構(gòu)造方法傳入一個監(jiān)聽器
this.listener=listener;
}
@Override
protected Integer doInBackground(String... strings) {//后臺計算，所有耗時操作
InputStream is = null;
RandomAccessFile saveFile = null;
FileOutputStream output;
File file = null;
try {
long downloadLength = 0;
String dolwnloadUrl = strings[0];
String filename = dolwnloadUrl.substring(dolwnloadUrl.lastIndexOf("/"));//切出下載文件名
String directroy = "/mnt/sdcard/Download";//規(guī)定下載路徑
file = new File(directroy + filename);
URL url = new URL(dolwnloadUrl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();//
connection.setRequestMethod("GET");
connection.setReadTimeout(5000);
connection.setConnectTimeout(5000);
connection.setDoInput(true);
connection.setDoOutput(true);
long contentlength = getContentLength(dolwnloadUrl);//獲取下載內(nèi)容長度
if (contentlength == 0) {
return TYPE_FAILED;
} else if (contentlength == downloadLength) {
return TYPE_SUCCESS;
}
if (file.exists()){
downloadLength=file.length();//讀取下載長度
}
saveFile = new RandomAccessFile(file, "rw");//開啟流
connection.setRequestProperty("RANGE", "bytes=" + downloadLength + "-");
is = connection.getInputStream();
saveFile.seek(downloadLength);
byte[] b = new byte[1024];
int count = 0;
int len = -1;
while ((len = is.read(b)) != -1) {
if (isCanceled) {
return TYPE_CANCELED;
} else if (isPaused) {
return TYPE_PAUSED;
} else {
saveFile.write(b, 0, len);
count += len;
int prpgress = (int) (((count + downloadLength) / (float) contentlength) * 100);//計算進度條
publishProgress(prpgress);//更新進度條
}
}
return TYPE_SUCCESS;
} catch(Exception e){
e.printStackTrace();
}finally{
try {
if (is != null) {
is.close();
}
if (saveFile != null) {
saveFile.close();
}
if (isCanceled && file != null) {
file.delete();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return TYPE_FAILED;
}
@Override
protected void onPostExecute(Integer integer) {執(zhí)行完成后調(diào)用收尾工作
switch (integer){
case TYPE_SUCCESS:
listener.onSuccess();
break;
case TYPE_FAILED:
listener.onFailed();
break;
case TYPE_PAUSED:
listener.onPause();
break;
case TYPE_CANCELED:
listener.onCanceled();
break;
default:break;
}
}
@Override
protected void onProgressUpdate(Integer... values) {
int progress=values[0];
if (progress>lastprogress){
listener.onProgress(progress);
lastprogress=progress;
}
}
public void pauseDowndload(){
isPaused=true;
}
public void canceDowndload(){
isCanceled=true;
}
private long getContentLength(String dolwnloadUrl) {
try {
URL url=new URL(dolwnloadUrl);
HttpURLConnection connection= (HttpURLConnection) url.openConnection();
long contentlength=connection.getContentLength();
return contentlength;
} catch (Exception e) {
e.printStackTrace();
}
return 0;
}
}
DownloadService
public class DownloadService extends Service {
private DownloadTask downloadTask;//下載任務(wù)
private String downloadUrl;//下載地址
private DownloadBinder mdownloadBinder=new DownloadBinder();
private DownloadListener listener=new DownloadListener() {
@Override
public void onProgress(int progress) {
getNotiFicationManager().notify(1,getNotification("Download...",progress));
}
@Override
public void onSuccess() {
downloadTask=null;
stopForeground(true);
getNotiFicationManager().notify(1,getNotification("Download Sucess",-1));
Toast.makeText(DownloadService.this,"Download Success",Toast.LENGTH_LONG).show();
}
@Override
public void onFailed() {
downloadTask=null;
stopForeground(true);
getNotiFicationManager().notify(1,getNotification("Download Failed",-1));
Toast.makeText(DownloadService.this,"Download Failed",Toast.LENGTH_LONG).show();
}
@Override
public void onPause() {
downloadTask=null;
Toast.makeText(DownloadService.this,"Download Paused",Toast.LENGTH_LONG).show();
}
@Override
public void onCanceled() {
downloadTask=null;
stopForeground(true);
Toast.makeText(DownloadService.this,"Download Cancled",Toast.LENGTH_LONG).show();
}
};
class DownloadBinder extends Binder{
public void startDownload(String url){
if (downloadTask==null){
downloadUrl=url;
downloadTask=new DownloadTask(listener);
downloadTask.execute(downloadUrl);
startForeground(1,getNotification("Dowloading...",0));
Toast.makeText(DownloadService.this,"Downloading...",Toast.LENGTH_LONG).show();
}
}
public void pauseDownload(){
if (downloadTask!=null){
downloadTask.pauseDowndload();
}
}
public void cancelDownload(){
if (downloadTask!=null){
downloadTask.canceDowndload();
}else {
if (downloadUrl!=null){
String filename=downloadUrl.substring(downloadUrl.lastIndexOf("/"));
String diectroy="/mnt/sdcard/Download";
File file=new File(diectroy+filename);
if(file.exists()){
file.delete();
}
getNotiFicationManager().cancel(1);
stopForeground(true);
Toast.makeText(DownloadService.this,"Download Cancled",Toast.LENGTH_LONG).show();
}
}
}
}
private NotificationManager getNotiFicationManager() {
return (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
}
private Notification getNotification(String title,int progress){
Intent intent=new Intent(this,MainActivity.class);
PendingIntent pi=PendingIntent.getActivity(this,0,intent,0);
NotificationCompat.Builder builder=new NotificationCompat.Builder(this);
builder.setSmallIcon(R.mipmap.ic_launcher);
builder.setLargeIcon(BitmapFactory.decodeResource(getResources(),R.mipmap.ic_launcher));
builder.setContentIntent(pi);
builder.setContentTitle(title);
if (progress>0){
builder.setContentText(progress+"%");
builder.setProgress(100,progress,false);
}
return builder.build();
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return mdownloadBinder;
}
}
DownloadListener
public interface DownloadListener {
void onProgress(int progress);//下載進度
void onSuccess();//下載成功
void onFailed();//下載失敗
void onPause();;//下載暫時
void onCanceled();//下載關(guān)閉
}
Activity
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private Button mBtnstartD,mBtnpauseD,mBtncancleD;
private DownloadService.DownloadBinder downloadBinder;
private EditText mEdtdownload;
private ServiceConnection connection=new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
downloadBinder=(DownloadService.DownloadBinder)iBinder;
}
@Override
public void onServiceDisconnected(ComponentName componentName) {
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mBtnstartD=(Button)findViewById(R.id.start_download);
mBtnpauseD=(Button)findViewById(R.id.pause_download);
mBtncancleD=(Button)findViewById(R.id.cancel_download);
mBtnstartD.setOnClickListener(this);
mBtnpauseD.setOnClickListener(this);
mBtncancleD.setOnClickListener(this);
mEdtdownload=(EditText)findViewById(R.id.download);
Intent intent=new Intent(this,DownloadService.class);
startService(intent);
bindService(intent,connection,BIND_AUTO_CREATE);
if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED){
ActivityCompat.requestPermissions(MainActivity.this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},1);
}
}
@Override
public void onClick(View view) {
if (downloadBinder==null){
Toast.makeText(MainActivity.this,"哈哈",Toast.LENGTH_LONG).show();
return;
}
switch (view.getId()){
case R.id.start_download:
String url=mEdtdownload.getText().toString().trim();
downloadBinder.startDownload(url);
break;
case R.id.pause_download:
downloadBinder.pauseDownload();
break;
case R.id.cancel_download:
downloadBinder.cancelDownload();
break;
default:break;
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
switch (requestCode){
case 1:if (grantResults.length>0&&grantResults[0]!=PackageManager.PERMISSION_GRANTED){
Toast.makeText(this,"拒絕將無法使用",Toast.LENGTH_LONG).show();
finish();
}
break;
default:break;
}
}
@Override
protected void onDestroy() {
super.onDestroy();
unbindService(connection);
}
