JAVA断点续传(B/S)（1）
JAVA断点续传(B/S)（1）
作者：不明 来源：CSDN 发表时间：2007-11-26 点击数：
说明：
SiteFileFetch.java 负责整个文件的抓取，控制内部线程(FileSplitterFetch类)。
FileSplitterFetch.java 负责部分文件的抓取。
FileAccess.java 负责文件的存储。
SiteInfoBean.java 要抓取的文件的信息，如文件保存的目录，名字，抓取文件的URL等。
Utility.java 工具类，放一些简单的方法。
TestMethod.java 测试类
/*
**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();
}
}
**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();
}
}
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