Multithreaded download instances in android
- 2020-05-17 06:23:59
- OfStack
public class MainActivity extends Activity {
// The statement controls
// Path and number of threads
private EditText et_url, et_num;
// The progress bar
public static ProgressBar pb_thread;
// Actions that show progress
private TextView tv_pb;
// Number of threads
public static int threadNum = 3;
// Each thread is responsible for the size of the download
public int blockSize;
public static int threadCount;// The number of
// Access to the path
public String path;
public static boolean flag = true;
// Record the value of the progress bar
public static int pb_count = 0;
public static Handler handler;
public static final int TEXTVALUE = 1;
public static int pb_num = 0;
public static int size = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_url = (EditText) findViewById(R.id.et_path);
et_num = (EditText) findViewById(R.id.et_threadNum);
pb_thread = (ProgressBar) findViewById(R.id.pb_down);
tv_pb = (TextView) findViewById(R.id.tv_pb);
handler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case TEXTVALUE:
System.out.println("-----------------------"
+ MainActivity.pb_count + "//////"
+ MainActivity.size);
// change TEXTView
pb_num = (MainActivity.pb_count * 100) / MainActivity.size;
tv_pb.setText(" The current progress is +" + pb_num + "%");
break;
default:
break;
}
}
};
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
// getMenuInflater().inflate(R.menu.down, menu);
return true;
}
// Download operation
public void downLoad(View v) {
// Change the variable value:
MainActivity.flag = true;
MainActivity.pb_count = 0;
path = et_url.getText().toString();
String threadNum_et = et_num.getText().toString();
if (TextUtils.isEmpty(path) || TextUtils.isEmpty(threadNum_et)) {
Toast.makeText(this, " Can't be empty ", Toast.LENGTH_LONG).show();
return;
}
Toast.makeText(this, "url:" + path + "--" + threadNum_et,
Toast.LENGTH_LONG).show();
// Convert to Numbers
threadNum = Integer.valueOf(threadNum_et);
new Thread(new Runnable() {
@Override
public void run() {
try {
// To create a URL object
URL url = new URL(path);
// To create a HttpURLConnection object
HttpURLConnection httpURLConnection = (HttpURLConnection) url
.openConnection();
// Set up the The way a request is sent
httpURLConnection.setRequestMethod("GET");
// Sets whether the request is timed out
httpURLConnection.setConnectTimeout(5000);
// Set up the
httpURLConnection
.setRequestProperty("User-Agent",
" Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Trident/6.0)");
// Whether the response is successful or not
if (httpURLConnection.getResponseCode() == 200) {
// Gets the size of the file
size = httpURLConnection.getContentLength();
System.out.println(" File size " + size);
// Set the maximum value of the progress bar
pb_thread.setMax(size);
// Create a file // Save to SD Card.
// First determine if you own it sdcard
if (Environment.getExternalStorageState().equals(
Environment.MEDIA_MOUNTED)) {
// To obtain sdCard File directory object
File sdFile = Environment
.getExternalStorageDirectory();
// Create file object
File file = new File(sdFile, "youdao.exe");
RandomAccessFile accessFile = new RandomAccessFile(
file, "rwd");
// Set the size of the file
accessFile.setLength(size);
// Size of download per thread
blockSize = size / threadNum;
// open 3 A thread Manipulate this file
for (int i = 1; i <= threadNum; i++) {
// 1 2 3
// Calculate where each thread starts
int startSize = (i - 1) * blockSize;
// End position
int endSize = (i) * blockSize;
// When the thread is last 1 In threads
if (i == threadNum) {
// Determine if the size of the file is greater than the calculated ending position
if (size > endSize) {
// End position Is equal to the File size
endSize = size;
}
}
// Create for each thread 1 A random read
RandomAccessFile threadAccessFile = new RandomAccessFile(
file, "rwd");
new Thread(new DownLoadThread(i,
threadAccessFile, startSize, endSize,
path)).start();
}
}
}
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}).start();
}
// Suspend operations
public void downPause(View v) {
Toast.makeText(this, " suspended ", Toast.LENGTH_LONG).show();
this.flag = false;
}
}
public class DownLoadThread implements Runnable {
// Download the package of the file
public RandomAccessFile accessFile;
// Where the thread started to download the file
public int startSize;
public int endSize;
// File download path The path
public String path;
public int threadId; // Thread identity
public DownLoadThread(int threadId, RandomAccessFile accessFile,
int startSize, int endSize, String path) {
this.threadId = threadId;
this.accessFile = accessFile;
this.startSize = startSize;
this.endSize = endSize;
this.path = path;
}
@Override
public void run() {
// perform run methods
try {
// Create a file to SD Card up
// First determine if you own it sdcard
if (Environment.getExternalStorageState().equals(
Environment.MEDIA_MOUNTED)) {
// To obtain sdCard File directory object
File sdFile = Environment.getExternalStorageDirectory();
File threadFile = new File(sdFile, threadId + ".txt");
if (threadFile.exists()) {
// Read the contents of the file
// Create an input stream object for the file
FileInputStream fis = new FileInputStream(threadFile);
// Read by the utility class
byte data[] = StreamTools.isToData(fis);
// Convert to a string
String threadLen = new String(data);
if ((threadLen != null) && (!"".equals(threadLen))) {
startSize = Integer.valueOf(threadLen);
// To solve 416bug The error
if (startSize > endSize) {
startSize = endSize - 1;
}
}
}
// Create a file
// create URL object
URL url = new URL(path);
// create HttpURLConnection object
HttpURLConnection httpURLConnection = (HttpURLConnection) url
.openConnection();
// Sets the header of the request
httpURLConnection.setRequestMethod("GET");
// Sets whether the request is timed out
httpURLConnection.setConnectTimeout(5000);
// Set up the
httpURLConnection
.setRequestProperty("User-Agent",
" Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Trident/6.0)");
// Key Settings
httpURLConnection.setRequestProperty("Range", "bytes="
+ startSize + "-" + endSize);
// Output current thread
System.out.println(" The current thread " + threadId + " Download start location :" + startSize
+ " End of download location :" + endSize);
// In response to success
// Set to read files randomly The starting position
accessFile.seek(startSize);
// Gets the corresponding flow object
InputStream is = httpURLConnection.getInputStream();
// Create an output stream object
byte buffer[] = new byte[1024];
int len = 0;
int threadTotal = 0;// Each thread saves the record after downloading /
while ((len = is.read(buffer)) != -1) {
accessFile.write(buffer, 0, len);
threadTotal += len;// Record the length of what you write //xml file
// Change the progress bar:
setProgressBar(len);
// Record the length of the file download by file
FileOutputStream fos = new FileOutputStream(threadFile);
fos.write((threadTotal + "").getBytes());
fos.flush();
fos.close();
// send handler The message
MainActivity.handler.sendEmptyMessage(MainActivity.TEXTVALUE);
if(!MainActivity.flag){
return;
}
}
accessFile.close();
is.close();
System.out.println(threadId + " Thread execution complete ");
// Thread operation
synchronized (MainActivity.class) {
MainActivity.threadCount++;
if (MainActivity.threadCount >= MainActivity.threadNum) {
for (int i = 1; i <= MainActivity.threadNum; i++) {
// To obtain sdCard The file on the
File deleteFile = new File(sdFile, i + ".txt");
if (deleteFile.exists()) {
// File deletion
deleteFile.delete();
}
}
}
}
}
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public synchronized void setProgressBar(int len){
MainActivity.pb_count+=len;
MainActivity.pb_thread.setProgress(MainActivity.pb_count);
}
}
public class StreamTools {
public static byte[] isToData(InputStream is) throws IOException{
// Byte output stream
ByteArrayOutputStream bops = new ByteArrayOutputStream();
// The cache where the data is read
byte buffer[] = new byte[1024];
// Read a record of length
int len = 0;
// Loop reads
while ((len = is.read(buffer)) != -1) {
bops.write(buffer, 0, len);
}
// Convert the read to byte An array of
byte data[] = bops.toByteArray();
bops.flush();
bops.close();
is.close();
return data;
}
}
Complete source code