Copy Code code as follows:
public class Mainactivity extends activity {
declaring controls
Path and number of threads
Private EditText Et_url, Et_num;
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;
Number of public static int threadcount;//
Access to Path
public String Path;
public static Boolean flag = TRUE;
Record the value of a 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 (msg) {
Super.handlemessage (msg);
Switch (msg.what) {
Case TextValue:
System.out.println ("-----------------------"
+ Mainactivity.pb_count + "//////"
+ mainactivity.size);
Change TextView
Pb_num = (Mainactivity.pb_count *)/mainactivity.size;
Tv_pb.settext ("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 action
public void DownLoad (View v) {
To change the value of a variable:
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, "cannot be empty", Toast.length_long). Show ();
Return
}
Toast.maketext (This, "URL:" + path + "--" + Threadnum_et,
Toast.length_long). Show ();
Convert to Number
Threadnum = integer.valueof (Threadnum_et);
New Thread (New Runnable () {
@Override
public void Run () {
try {
Create a URL object
URL url = new URL (path);
Create a HttpURLConnection object
HttpURLConnection httpurlconnection = (httpurlconnection) URL
. OpenConnection ();
Set how send requests are sent
Httpurlconnection.setrequestmethod ("get");
Set whether the request is timed out
Httpurlconnection.setconnecttimeout (5000);
Set up
HttpURLConnection
. Setrequestproperty ("User-agent",
"Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; trident/6.0) ");
Whether to respond successfully
if (httpurlconnection.getresponsecode () = = 200) {
Get the size of a file
Size = Httpurlconnection.getcontentlength ();
SYSTEM.OUT.PRINTLN ("Size of file" + sizes);
Set the maximum of a progress bar
Pb_thread.setmax (size);
Create File//Save to SD card
First, determine if you have SDcard
if (Environment.getexternalstoragestate (). Equals (
environment.media_mounted)) {
Get sdcard File directory object
File sdfile = Environment
. getExternalStorageDirectory ();
Create a File object
File File = new file (sdfile, "Youdao.exe");
Randomaccessfile accessfile = new Randomaccessfile (
File, "RWD");
To set the size of a file
Accessfile.setlength (size);
The size of each thread download
BlockSize = Size/threadnum;
Open three threads to manipulate this file
for (int i = 1; I <= threadnum; i++) {
1 2 3
To calculate where each thread starts
int startsize = (i-1) * blockSize;
End Position
int endsize = (i) * blockSize;
When the thread is the last thread
if (i = = threadnum) {
Determines whether the file size is greater than the computed end position
if (Size > Endsize) {
The end position equals the size of the file
endsize = size;
}
}
Create a random read for each thread
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 ();
}
Pause operation
public void Downpause (View v) {
Toast.maketext (this, pause, Toast.length_long). Show ();
This.flag = false;
}
}
Copy Code code as follows:
public class Downloadthread implements Runnable {
Packaging for downloading files
Public Randomaccessfile Accessfile;
The starting position of the thread download file
public int startsize;
public int endsize;
Path to file downloads
public String Path;
public int threadId; Identification of threads
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 () {
Execute the Run method
try {
Create file to SD card
First, determine if you have SDcard
if (Environment.getexternalstoragestate (). Equals (
environment.media_mounted)) {
Get 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 a file
FileInputStream fis = new FileInputStream (threadfile);
Use tool class to read
byte data[] = Streamtools.istodata (FIS);
Into strings
String threadlen = new string (data);
if (Threadlen!= null) && (! "". Equals (Threadlen))) {
Startsize = integer.valueof (Threadlen);
Troubleshoot 416bug errors
if (Startsize > Endsize) {
Startsize = endSize-1;
}
}
}
Create a file
Create a URL object
URL url = new URL (path);
Creating HttpURLConnection Objects
HttpURLConnection httpurlconnection = (httpurlconnection) URL
. OpenConnection ();
Set the header of the request
Httpurlconnection.setrequestmethod ("get");
Set whether the request is timed out
Httpurlconnection.setconnecttimeout (5000);
Set up
HttpURLConnection
. Setrequestproperty ("User-agent",
"Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; trident/6.0) ");
The key settings
Httpurlconnection.setrequestproperty ("Range", "bytes=")
+ startsize + "-" + endsize);
Output Current thread
System.out.println ("Current thread" + threadId + "Download start position:" + startsize
+ "Download End location:" + endsize);
Response successful
Set the starting position of random read files
Accessfile.seek (startsize);
Get the corresponding Stream object
InputStream is = Httpurlconnection.getinputstream ();
Creating an output Stream object
byte buffer[] = new byte[1024];
int len = 0;
int threadtotal = 0;//Save record after each thread download
while (len = is.read (buffer))!=-1) {
Accessfile.write (buffer, 0, Len);
Threadtotal + = len;//Record the length//xml file you write
Change the progress bar:
Setprogressbar (len);
The length of the file download through the document record
FileOutputStream fos = new FileOutputStream (threadfile);
Fos.write ((Threadtotal + ""). GetBytes ());
Fos.flush ();
Fos.close ();
Send Handler message
MainActivity.handler.sendEmptyMessage (Mainactivity.textvalue);
if (! Mainactivity.flag) {
Return
}
}
Accessfile.close ();
Is.close ();
System.out.println (threadId + "thread execution complete");
Threading actions
Synchronized (Mainactivity.class) {
mainactivity.threadcount++;
if (Mainactivity.threadcount >= mainactivity.threadnum) {
for (int i = 1; I <= mainactivity.threadnum; i++) {
Get the files on the SDcard
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);
}
}
Copy Code code as follows:
public class Streamtools {
public static byte[] Istodata (InputStream is) throws ioexception{
BYTE output stream
Bytearrayoutputstream Bops = new Bytearrayoutputstream ();
Read cache of data
byte buffer[] = new byte[1024];
Read the length of the record
int len = 0;
Looping read
while (len = is.read (buffer))!=-1) {
Bops.write (buffer, 0, Len);
}
Converts the read content into a byte array
byte data[] = Bops.tobytearray ();
Bops.flush ();
Bops.close ();
Is.close ();
return data;
}
}
Complete source
