android 多线程并发下载文件

package com.wansha;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;

import com.wansha.download.util.DownloadUtil;

public class Download extends Activity {
private ProgressBar bar1;
private Button downFile;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
this.bar1 = (ProgressBar)this.findViewById(R.id.bar1);
this.downFile = (Button)this.findViewById(R.id.downfile);
this.downFile.setOnClickListener(new downFileListener());

}
class downFileListener implements OnClickListener{
public void onClick(View arg0) {
bar1.setVisibility(View.VISIBLE);
DownloadUtil downloadutil = new DownloadUtil();
downloadutil.Save2SDCard("http://192.168.0.137:8080/navigater/admin/SSHDemo.zip", "peng/", "sharp.zip");

}
}
Handler handler = new Handler(){
public void handleMessage(Message msg) {
Log.d("mydebug", "hehh!" + msg.arg1);
bar1.setProgress(msg.arg1);
if(msg.arg1==100){
bar1.setVisibility(View.GONE);
}
};
};
}

package com.wansha.download.util;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import android.util.Log;

public class DownloadFile {
private File file;
private String url;
private String fileName;
private int startPos;
private int endPos;
private long totalSize;
private int threadNumTotal =1;
private int currentThread =1;
private static int BUFFER_SIZE = 1024*80;

public int getBUFFER_SIZE() {
return BUFFER_SIZE;
}
public int getThreadNumTotal() {
return threadNumTotal;
}
public void setThreadNumTotal(int threadNumTotal) {
this.threadNumTotal = threadNumTotal;
}
public int getCurrentThread() {
return currentThread;
}
public void setCurrentThread(int currentThread) {
this.currentThread = currentThread;
}
public File getFile() {
return file;
}
public void setFile(File file) {
this.file = file;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getFileName() {
return fileName;
}
public void setFileName(String fileName) {
this.fileName = fileName;
}
public int getStartPos() {
return startPos;
}
public void setStartPos(int startPos) {
this.startPos = startPos;
}
public int getEndPos() {
return endPos;
}
public void setEndPos(int endPos) {
this.endPos = endPos;
}
public long getTotalSize() {
return totalSize;
}
public void setTotalSize(long totalSize) {
this.totalSize = totalSize;
}

public long getURLTotalSize() {
try{
URL url = new URL(this.url);
HttpURLConnection httpConn = (HttpURLConnection)url.openConnection();
httpConn.setRequestMethod("GET");                         //以GET方式连接
if(httpConn.getResponseCode() == HttpURLConnection.HTTP_OK){
return httpConn.getContentLength();
}
}catch(Exception ex){
ex.printStackTrace();
return 0;
}
return 0;
}

public InputStream getInputStreamByThreadNum(){
InputStream is = null;
try{
if(this.url != null && !"".equals(this.url)){
long urlTotalSize = getURLTotalSize();
Log.d("mydebug", "threadNumTotal         " + this.threadNumTotal);
long spanSize = (long)Math.ceil((float)urlTotalSize/this.threadNumTotal);
Log.d("mydebug", "spanSize         " + spanSize);
this.setStartPos((int)((this.currentThread-1)*spanSize));
int ends = (int)(this.currentThread*spanSize-1);
if(ends > urlTotalSize){
this.setEndPos((int)urlTotalSize-1);
}else{
this.setEndPos(ends);
}

URL url = new URL(this.url);
HttpURLConnection httpConn = (HttpURLConnection)url.openConnection();
httpConn.setRequestMethod("GET");                         //以GET方式连接
httpConn.setRequestProperty("Connection", "Keep-Alive");  //保持一直连接
httpConn.setConnectTimeout(60 * 1000 * 5);                //连接超时5分钟
httpConn.setAllowUserInteraction(true);
httpConn.setRequestProperty("Range", "bytes=" + getStartPos() + "-" + getEndPos());
Log.d("mydebug", "         " + getStartPos() + "            " + getEndPos());
is = new BufferedInputStream(httpConn.getInputStream(),DownloadFile.BUFFER_SIZE);
}
}catch(Exception ex){
ex.printStackTrace();
}
return is;
}

public InputStream getInputStreamByPos(){
try{
if(this.url != null && !"".equals(this.url)){
if(this.startPos != 0 || this.endPos != 0){
URL url = new URL(this.url);
HttpURLConnection httpConn = (HttpURLConnection)url.openConnection();
httpConn.setRequestMethod("GET");                         //以GET方式连接
httpConn.setRequestProperty("Connection", "Keep-Alive");  //保持一直连接
httpConn.setConnectTimeout(60 * 1000 * 5);                //连接超时5分钟
httpConn.setAllowUserInteraction(true);
httpConn.setRequestProperty("Range", "bytes=" + getStartPos() + "-" + getEndPos());
Log.d("mydebug", "readding....6           " + httpConn.getResponseCode());
//					if(httpConn.getResponseCode() == HttpURLConnection.HTTP_OK){
Log.d("mydebug", "readding....8           " + this.startPos + "````````````````````````" + this.endPos);
Log.d("mydebug", "hello world");
//			                httpConn.setRequestProperty("Range", "bytes=" + getStartPos() + "-" + getEndPos());
Log.d("mydebug", "start ------>" + this.startPos + "  endPos" + this.endPos);
Log.d("mydebug", "readding....7");
return new BufferedInputStream(httpConn.getInputStream(),DownloadFile.BUFFER_SIZE);

//					}
}
}
}catch(Exception ex){
ex.printStackTrace();
return null;
}
return null;
}
public static void main(String[] args) throws Exception {
DownloadFile downloadFile = new DownloadFile();
downloadFile.setUrl("http://www.baidu.com/index.html");
downloadFile.getInputStreamByPos();
}
}

package com.wansha.download.util;

import java.io.File;
import java.io.InputStream;
import java.io.RandomAccessFile;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.util.Log;

public class DownloadUtil {
private static int threadNum = 10;
private int sign = 0;
public static int getThreadNum() {
return threadNum;
}

public static void setThreadNum(int threadNum) {
DownloadUtil.threadNum = threadNum;
}

public DownloadUtil(){

}

private final static String SDPATH = Environment.getExternalStorageDirectory().getPath() + "/";

public boolean isExistFile(String filePath){
File file = new File(filePath);
return file.exists();
}

public void createDir(String dirPath){
if(dirPath != null || !"".equals(dirPath)){
File file = new File(dirPath);
if(!file.isDirectory()){
file.mkdirs();
}
}
}

public int Save2SDCard(String urlAddress, String saveDir, String fileName){
createDir(DownloadUtil.SDPATH + saveDir);
try{
File file = new File(DownloadUtil.SDPATH + saveDir, fileName);
Log.d("mydebug", "fileName....1" + DownloadUtil.SDPATH + saveDir + fileName);
if(file.exists())file.delete();
ExecutorService service = Executors.newFixedThreadPool(10);
CountDownLatch countDownLatch = new CountDownLatch(DownloadUtil.threadNum);
Log.d("mydebug", "readding....1");
for(int i=1; i<=DownloadUtil.threadNum; i++){
Log.d("mydebug", "readding....2");
DownloadFile downloadFile = new DownloadFile();
downloadFile.setUrl(urlAddress);
downloadFile.setThreadNumTotal(DownloadUtil.threadNum);
downloadFile.setCurrentThread(i);
RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rwd");

//			boolean flag = this.handler.post(new SaveFileThread(countDownLatch, this.handler));
service.execute(new SaveFileThread(randomAccessFile, downloadFile, countDownLatch));
}
countDownLatch.await();
service.shutdown();
Log.d("mydebug", "download is finish!");
return 0;
}catch(Exception ex){
ex.printStackTrace();
return -1;
}
}

class MyRunnable implements Runnable{
private Handler handler;
public MyRunnable(){

}
public MyRunnable(Handler handler){
this.handler = handler;
}
public void run() {
sign += 10;
Message message = this.handler.obtainMessage();
message.arg1 = sign;
try{
Thread.sleep(2000);
}catch(Exception ex){
ex.printStackTrace();
}
this.handler.sendMessage(message);
};

};

class SaveFileThread implements Runnable{
private RandomAccessFile randomFile;
private DownloadFile downloadFile;
private CountDownLatch countDownLatch;
public SaveFileThread() {
}

public SaveFileThread(RandomAccessFile randomFile, DownloadFile downloadFile, CountDownLatch countDownLatch) {
this.randomFile = randomFile;
this.downloadFile = downloadFile;
this.countDownLatch = countDownLatch;
}

public void run() {
try{
InputStream is = this.downloadFile.getInputStreamByThreadNum();
this.randomFile.seek(this.downloadFile.getStartPos());

byte[] by = new byte[1024*80];
int length = 0;

while(-1 != (length = is.read(by))){
this.randomFile.write(by, 0, length);
}

is.close();
this.randomFile.close();
this.countDownLatch.countDown();

}catch(Exception ex){
ex.printStackTrace();
}
}
}
}