一个多线程、支持断点续传的java源码.java

一个多线程、支持断点续传的java源码

/**SiteFileFetch.java*/
package NetFox;
import java.io.*;
import java.net.*;
public class SiteFileFetch extends Thread {
	SiteInfoBean siteInfoBean = null; //文件信息Bean
	long[] nStartPos; //开始位置
	long[] nEndPos; //结束位置
	FileSplitterFetch[] fileSplitterFetch; //子线程对象
	long nFileLength; //文件长度
	boolean bFirst = true; //是否第一次取文件
	boolean bStop = false; //停止标志
	File tmpFile; //文件下载的临时信息
	DataOutputStream output; //输出到文件的输出流

   public SiteFileFetch(SiteInfoBean bean) throws IOException{
	siteInfoBean = bean;
	//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
	tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
	if(tmpFile.exists ()){
		bFirst = false;
		read_nPos();
	}else{
		nStartPos = new long[bean.getNSplitter()];
		nEndPos = new long[bean.getNSplitter()];
	}
   }

	public void run(){
		//获得文件长度
		//分割文件
		//实例FileSplitterFetch
		//启动FileSplitterFetch线程
		//等待子线程返回
		try{
			if(bFirst){
				nFileLength = getFileSize();
				if(nFileLength == -1){
				System.err.println("File Length is not known!");
			}else if(nFileLength == -2){
				System.err.println("File is not access!");
			}else{
				for(int i=0;i<nStartPos.length;i++){
					nStartPos[i] = (long)(i*(nFileLength/nStartPos.length));
				}

				for(int i=0;i<nEndPos.length-1;i++){
					nEndPos[i] = nStartPos[i+1];
				}
				nEndPos[nEndPos.length-1] = nFileLength;
			}
		}

		//启动子线程
		fileSplitterFetch = new FileSplitterFetch[nStartPos.length];
		for(int i=0;i<nStartPos.length;i++){
			fileSplitterFetch[i] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nStartPos[i],nEndPos[i],i);
			Utility.log("Thread " + i + " , nStartPos = " + nStartPos[i] + ", nEndPos = " + nEndPos[i]);
			fileSplitterFetch[i].start();
		}

		// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(),
		//siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1);
		// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ",nEndPos = " + nFileLength);
		// fileSplitterFetch[nPos.length-1].start();
		//等待子线程结束
		//int count = 0;
		//是否结束while循环
		
		boolean breakWhile = false;
		while(!bStop){
			write_nPos();
			Utility.sleep(500);
			breakWhile = true;
			for(int i=0;i<nStartPos.length;i++){
				if(!fileSplitterFetch[i].bDownOver){
					breakWhile = false;
					break;
				}
			}
			if(breakWhile)
				break;
			//count++;
			//if(count>4)
			// siteStop();
		}
		System.err.println("文件下载结束！");
	}catch(Exception e){e.printStackTrace ();}

}

	//获得文件长度
	public long getFileSize(){
		int nFileLength = -1;
		try{
			URL url = new URL(siteInfoBean.getSSiteURL());
			HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();
			httpConnection.setRequestProperty("User-Agent","NetFox");
			int responseCode=httpConnection.getResponseCode();
			if(responseCode>=400){
				processErrorCode(responseCode);
				return -2; //-2 represent access is error
			}
			
			String sHeader;
			for(int i=1;;i++){
				//DataInputStream in = new DataInputStream(httpConnection.getInputStream ());
				//Utility.log(in.readLine());
				sHeader=httpConnection.getHeaderFieldKey(i);
				if(sHeader!=null){
					if(sHeader.equals("Content-Length")){
						nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader));
						break;
					}

				}else{
					break;
				}
			}
		}catch(IOException e){
			e.printStackTrace ();
		}catch(Exception e){
			e.printStackTrace ();
		}
		Utility.log(nFileLength);
		return nFileLength;
	}

//保存下载信息（文件指针位置）
private void write_nPos(){
try{
output = new DataOutputStream(new FileOutputStream(tmpFile));
output.writeInt(nStartPos.length);
for(int i=0;i<nStartPos.length;i++){
// output.writeLong(nPos[i]);
output.writeLong(fileSplitterFetch[i].nStartPos);
output.writeLong(fileSplitterFetch[i].nEndPos);
}
output.close();
}catch(IOException e){e.printStackTrace ();}
catch(Exception e){e.printStackTrace ();}
}

//读取保存的下载信息（文件指针位置）
private void read_nPos(){
try{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile));
int nCount = input.readInt();
nStartPos = new long[nCount];
nEndPos = new long[nCount];
for(int i=0;i<nStartPos.length;i++){
nStartPos[i] = input.readLong();
nEndPos[i] = input.readLong();
}
input.close();
}catch(IOException e){e.printStackTrace ();}
catch(Exception e){e.printStackTrace ();}
}




private void processErrorCode(int nErrorCode){
System.err.println("Error Code : " + nErrorCode);
}

//停止文件下载
public void siteStop(){
bStop = true;
for(int i=0;i<nStartPos.length;i++)
fileSplitterFetch[i].splitterStop();
}
}


/***FileSplitterFetch.java*/


package NetFox;
import java.io.*;
import java.net.*;
public class FileSplitterFetch extends Thread {

String sURL; //File URL
long nStartPos; //File Snippet Start Position
long nEndPos; //File Snippet End Position
int nThreadID; //Thread's ID
boolean bDownOver = false; //Downing is over
boolean bStop = false; //Stop identical
FileAccessI fileAccessI = null; //File Access interface

public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException{
this.sURL = sURL;
this.nStartPos = nStart;
this.nEndPos = nEnd;
nThreadID = id;
fileAccessI = new FileAccessI(sName,nStartPos);
}

public void run(){
while(nStartPos < nEndPos && !bStop){
try{
URL url = new URL(sURL);
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();
httpConnection.setRequestProperty("User-Agent","NetFox");
String sProperty = "bytes="+nStartPos+"-";
httpConnection.setRequestProperty("RANGE",sProperty);
Utility.log(sProperty);
InputStream input = httpConnection.getInputStream();
//logResponseHead(httpConnection);
byte[] b = new byte[1024];
int nRead;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop){
nStartPos += fileAccessI.write(b,0,nRead);
//if(nThreadID == 1)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);
}

Utility.log("Thread " + nThreadID + " is over!");
bDownOver = true;
//nPos = fileAccessI.write (b,0,nRead);
}catch(Exception e){e.printStackTrace ();}
}

}
//打印回应的头信息
public void logResponseHead(HttpURLConnection con){
for(int i=1;;i++){
String header=con.getHeaderFieldKey(i);
if(header!=null)
//responseHeaders.put(header,httpConnection.getHeaderField(header));
Utility.log(header+" : "+con.getHeaderField(header));
else
break;
}
}


public void splitterStop(){
bStop = true;
}

}

/***FileAccess.java*/
package NetFox;
import java.io.*;

public class FileAccessI implements Serializable{
RandomAccessFile oSavedFile;
long nPos;
public FileAccessI() throws IOException{
this("",0);
}

public FileAccessI(String sName,long nPos) throws IOException{
oSavedFile = new RandomAccessFile(sName,"rw");
this.nPos = nPos;
oSavedFile.seek(nPos);
}


public synchronized int write(byte[] b,int nStart,int nLen){
int n = -1;
try{
oSavedFile.write(b,nStart,nLen);
n = nLen;
}catch(IOException e){
e.printStackTrace ();
}

return n;
}

}

/***SiteInfoBean.java*/
package NetFox;
public class SiteInfoBean {

private String sSiteURL; //Site's URL
private String sFilePath; //Saved File's Path
private String sFileName; //Saved File's Name
private int nSplitter; //Count of Splited Downloading File

public SiteInfoBean(){
//default value of nSplitter is 5
this("","","",5);
}

public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter){
sSiteURL= sURL;
sFilePath = sPath;
sFileName = sName;
this.nSplitter = nSpiltter;
}

public String getSSiteURL(){
return sSiteURL;
}

public void setSSiteURL(String value){
sSiteURL = value;
}

public String getSFilePath(){
return sFilePath;
}

public void setSFilePath(String value){
sFilePath = value;
}

public String getSFileName(){
return sFileName;
}

public void setSFileName(String value){
sFileName = value;
}

public int getNSplitter(){
return nSplitter;
}

public void setNSplitter(int nCount){
nSplitter = nCount;
}

}

/***Utility.java*/
package NetFox;
public class Utility {

public Utility(){

}




public static void sleep(int nSecond){

try{
Thread.sleep(nSecond);
}catch(Exception e){
e.printStackTrace ();
}

}

public static void log(String sMsg){
System.err.println(sMsg);
}

public static void log(int sMsg){
System.err.println(sMsg);
}

}


/***TestMethod.java*/
package NetFox;

public class TestMethod {

public TestMethod(){ ///xx/weblogic60b2_win.exe
try{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5);
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5);
SiteFileFetch fileFetch = new SiteFileFetch(bean);
fileFetch.start();
}catch(Exception e){e.printStackTrace ();}
}


public static void main(String[] args){
new TestMethod();
}
}