public class MainActivity extends Activity {
protected static final int DOWN = 0;
protected static final int SEER = 1;
private Context context;
private EditText ed;
private ProgressBar pb;
public static int threadcount=3;
public static int runnling=3;
public int cureatProcess=0;//当前进度
private Handler handler =new Handler(){
public void handleMessage(android.os.Message msg) {
switch (msg.what) {
case DOWN:
Toast.makeText(getApplicationContext(), "下载错误", 0).show();
break;
case SEER:
Toast.makeText(getApplicationContext(), "下载失败", 0).show();
break;
}
};
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ed=(EditText)findViewById(R.id.ed_path);
pb=(ProgressBar)findViewById(R.id.pb);
}
public void paly(View view){
final String path=ed.getText().toString().trim();
if(TextUtils.isEmpty(path)){
Toast.makeText(getApplicationContext(), "请输入地址", 0).show();
return;
}
new Thread(){
public void run(){
//String path="http://down9.869v.com/setup_445.exe";
try {
URL url=new URL(path);
HttpURLConnection con= (HttpURLConnection) url.openConnection();
con.setReadTimeout(6000);
con.setRequestMethod("GET");
int code= con.getResponseCode();
if(code==200){
int length= con.getContentLength();//已经设置了请求的位置//返回的是当前位置对应文件的输入流
pb.setMax(length);//获取进度条最大值
RandomAccessFile raf=new RandomAccessFile((/"sdscard"/+"421.exe", "rwd");//记录当前线程下载的数据长度
raf.close();
//System.out.print("文件长度:"+length);
int bolak =length/threadcount;
for(int threadID=1;threadID<=threadcount;threadID++){
int starIndex=(threadID-1)*bolak;
int endIndex=threadID*bolak-1;
if(threadID==threadcount){
endIndex=length;
}
System.out.println("线程"+threadID+"下载---->"+starIndex+"----->"+endIndex);
new MyThread(path, threadID, starIndex, endIndex).start();
}
}else{
System.out.print("读取长度失败");
Message msg=new Message();
handler.sendMessage(msg);
msg.what=SEER;
}
} catch (Exception e) {
e.printStackTrace();
Message msg=new Message();
handler.sendMessage(msg);
msg.what=DOWN;
}
}
}.start();
}
public class MyThread extends Thread{
public MyThread(String path, int threadID, int starIndex, int endIndex) {
super();
this.path = path;
this.threadID = threadID;
this.starIndex = starIndex;
this.endIndex = endIndex;
}
private String path;
private int threadID;
private int starIndex;
private int endIndex;
public void run(){
try {
//检查是否在记录下载长度的文件 如果存在读取这个文件的数据
File tempFile =new File(context.MODE_PRIVATE+threadID+".txt");
if(tempFile.exists()&&tempFile.length()>0){
FileInputStream fis=new FileInputStream(tempFile);
byte[] tpem=new byte[1024];
int leng =fis.read(tpem);
String dowmlod =new String(tpem,0,leng);
int downlodalenInt= Integer.parseInt(dowmlod);
int alreadyDown =downlodalenInt-starIndex;
cureatProcess+=alreadyDown;//计算上次断点已经下载的值
starIndex=downlodalenInt;//修改下载的真实开始位置
fis.close();
}
URL url=new URL(path);
HttpURLConnection con =(HttpURLConnection) url.openConnection();
con.setRequestMethod("GET");
con.setRequestProperty("Range", "byte="+starIndex+"-"+endIndex);
System.out.println("线程真实下载位置"+threadID+"下载----"+starIndex);
con.setReadTimeout(8000);
int code=con.getResponseCode();
System.out.println("code"+code);
InputStream is= con.getInputStream();
RandomAccessFile raf=new RandomAccessFile((/"sdscard"/+"421.exe", "rwd");
raf.seek(starIndex);
int len=0;
byte[]buffer=new byte[1024];
int total=0;
while((len=is.read(buffer))!=-1){
RandomAccessFile flie =new RandomAccessFile((/"sdscard"/+threadID+".txt ","rwd");
raf.write(buffer,0,len);
total+=len;
System.out.println("线程"+threadID+"total:"+total);
flie.write((total+starIndex+"").getBytes());//记录下载的位置
flie.close();
synchronized (MainActivity.this) {
cureatProcess+=len;//记录当前总进度
pb.setProgress(cureatProcess);
}
}
is.close();
raf.close();
System.out.println("线程ID"+threadID+"下载完毕......");
} catch (Exception e) {
e.printStackTrace();
}finally{
threadFins();
}
}
private synchronized void threadFins() {
runnling--;
if(runnling==0){
for(int i=1 ;i<=3;i++){
File file=new File(/"sdscard"/+i+".txt");
file.delete();
}
System.out.println("文件下载半壁删除所有下载记录");
}
}
}
}