Servlet
Java代码 复制代码 收藏代码
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URLDecoder;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.bsteel.cloud.storage.servlet.base.BaseServlet;
import com.bsteel.cloud.storage.utils.FileUtil;
/**
* 文件下载(支持断点续传【迅雷快车旋风FirefoxChrome】)
* @author jdkleo
*
*/
public class FileIoServlet extends BaseServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
this.doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
download(request,response);
}
/**
* 文件下载
* @param request
* @param response
* @throws UnsupportedEncodingException
*/
private void download(HttpServletRequest request,HttpServletResponse response) throws UnsupportedEncodingException {
File downloadFile = getFile(request);
long pos = FileUtil.headerSetting(downloadFile, request, response);
// log.info("跳过"+pos);
ServletOutputStream os = null;
BufferedOutputStream out = null;
RandomAccessFile raf = null;
byte b[] = new byte[1024];//暂存容器
try {
os = response.getOutputStream();
out = new BufferedOutputStream(os);
raf = new RandomAccessFile(downloadFile, "r");
raf.seek(pos);
try {
int n = 0;
while ((n = raf.read(b, 0, 1024)) != -1) {
out.write(b, 0, n);
}
out.flush();
} catch(IOException ie) {
}
} catch (Exception e) {
log.error(e.getMessage(), e);
} finally {
if (out != null) {
try {
out.close();
} catch (IOException e) {
log.error(e.getMessage(), e);
}
}
if (raf != null) {
try {
raf.close();
} catch (IOException e) {
log.error(e.getMessage(), e);
}
}
}
}
private File getFile(HttpServletRequest request) throws UnsupportedEncodingException {
String uriStr = request.getParameter("uri");
if (null != uriStr){
uriStr = URLDecoder.decode(uriStr,"UTF-8");
if (uriStr.startsWith("file://")){
uriStr = uriStr.substring(7);
return new File(uriStr);
}else if (uriStr.startsWith("hbase://")){
try {
return new File(new URI(uriStr));
} catch (URISyntaxException e) {
log.error(e.getMessage(),e);
}
}
}
throw new RuntimeException("it's not a real uri");
}
}
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URLDecoder;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.bsteel.cloud.storage.servlet.base.BaseServlet;
import com.bsteel.cloud.storage.utils.FileUtil;
/**
* 文件下载(支持断点续传【迅雷快车旋风FirefoxChrome】)
* @author jdkleo
*
*/
public class FileIoServlet extends BaseServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
this.doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
download(request,response);
}
/**
* 文件下载
* @param request
* @param response
* @throws UnsupportedEncodingException
*/
private void download(HttpServletRequest request,HttpServletResponse response) throws UnsupportedEncodingException {
File downloadFile = getFile(request);
long pos = FileUtil.headerSetting(downloadFile, request, response);
// log.info("跳过"+pos);
ServletOutputStream os = null;
BufferedOutputStream out = null;
RandomAccessFile raf = null;
byte b[] = new byte[1024];//暂存容器
try {
os = response.getOutputStream();
out = new BufferedOutputStream(os);
raf = new RandomAccessFile(downloadFile, "r");
raf.seek(pos);
try {
int n = 0;
while ((n = raf.read(b, 0, 1024)) != -1) {
out.write(b, 0, n);
}
out.flush();
} catch(IOException ie) {
}
} catch (Exception e) {
log.error(e.getMessage(), e);
} finally {
if (out != null) {
try {
out.close();
} catch (IOException e) {
log.error(e.getMessage(), e);
}
}
if (raf != null) {
try {
raf.close();
} catch (IOException e) {
log.error(e.getMessage(), e);
}
}
}
}
private File getFile(HttpServletRequest request) throws UnsupportedEncodingException {
String uriStr = request.getParameter("uri");
if (null != uriStr){
uriStr = URLDecoder.decode(uriStr,"UTF-8");
if (uriStr.startsWith("file://")){
uriStr = uriStr.substring(7);
return new File(uriStr);
}else if (uriStr.startsWith("hbase://")){
try {
return new File(new URI(uriStr));
} catch (URISyntaxException e) {
log.error(e.getMessage(),e);
}
}
}
throw new RuntimeException("it's not a real uri");
}
}
Range支持
Java代码 复制代码 收藏代码
import java.io.File;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 文件处理工具
* @author jdkleo
*
*/
public class FileUtil {
/**
* 断点续传支持
* @param file
* @param request
* @param response
* @return 跳过多少字节
*/
public static long headerSetting(File file,HttpServletRequest request, HttpServletResponse response) {
long len = file.length();//文件长度
if ( null == request.getHeader("Range") ){
setResponse(new RangeSettings(len),file.getName(),response);
return 0;
}
String range = request.getHeader("Range").replaceAll("bytes=", "");
RangeSettings settings = getSettings(len,range);
setResponse(settings,file.getName(),response);
return settings.getStart();
}
private static void setResponse(RangeSettings settings,String fileName, HttpServletResponse response) {
response.addHeader("Content-Disposition", "attachment; filename="" + IoUtil.toUtf8String(fileName) + """);
response.setContentType( IoUtil.setContentType(fileName));// set the MIME type.
if (!settings.isRange())
{
response.addHeader("Content-Length", String.valueOf(settings.getTotalLength()));
}
else
{
long start = settings.getStart();
long end = settings.getEnd();
long contentLength = settings.getContentLength();
response.setStatus(javax.servlet.http.HttpServletResponse.SC_PARTIAL_CONTENT);
response.addHeader("Content-Length", String.valueOf(contentLength));
String contentRange = new StringBuffer("bytes ").append(start).append("-").append(end).append("/").append(settings.getTotalLength()).toString();
response.setHeader("Content-Range", contentRange);
}
}
private static RangeSettings getSettings(long len, String range) {
long contentLength = 0;
long start = 0;
long end = 0;
if (range.startsWith("-"))// -500，最后500个
{
contentLength = Long.parseLong(range.substring(1));//要下载的量
end = len-1;
start = len - contentLength;
}
else if (range.endsWith("-"))//从哪个开始
{
start = Long.parseLong(range.replace("-", ""));
end = len -1;
contentLength = len - start;
}
else//从a到b
{
String[] se = range.split("-");
start = Long.parseLong(se[0]);
end = Long.parseLong(se[1]);
contentLength = end-start+1;
}
return new RangeSettings(start,end,contentLength,len);
}
}
import java.io.File;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 文件处理工具
* @author jdkleo
*
*/
public class FileUtil {
/**
* 断点续传支持
* @param file
* @param request
* @param response
* @return 跳过多少字节
*/
public static long headerSetting(File file,HttpServletRequest request, HttpServletResponse response) {
long len = file.length();//文件长度
if ( null == request.getHeader("Range") ){
setResponse(new RangeSettings(len),file.getName(),response);
return 0;
}
String range = request.getHeader("Range").replaceAll("bytes=", "");
RangeSettings settings = getSettings(len,range);
setResponse(settings,file.getName(),response);
return settings.getStart();
}
private static void setResponse(RangeSettings settings,String fileName, HttpServletResponse response) {
response.addHeader("Content-Disposition", "attachment; filename="" + IoUtil.toUtf8String(fileName) + """);
response.setContentType( IoUtil.setContentType(fileName));// set the MIME type.
if (!settings.isRange())
{
response.addHeader("Content-Length", String.valueOf(settings.getTotalLength()));
}
else
{
long start = settings.getStart();
long end = settings.getEnd();
long contentLength = settings.getContentLength();
response.setStatus(javax.servlet.http.HttpServletResponse.SC_PARTIAL_CONTENT);
response.addHeader("Content-Length", String.valueOf(contentLength));
String contentRange = new StringBuffer("bytes ").append(start).append("-").append(end).append("/").append(settings.getTotalLength()).toString();
response.setHeader("Content-Range", contentRange);
}
}
private static RangeSettings getSettings(long len, String range) {
long contentLength = 0;
long start = 0;
long end = 0;
if (range.startsWith("-"))// -500，最后500个
{
contentLength = Long.parseLong(range.substring(1));//要下载的量
end = len-1;
start = len - contentLength;
}
else if (range.endsWith("-"))//从哪个开始
{
start = Long.parseLong(range.replace("-", ""));
end = len -1;
contentLength = len - start;
}
else//从a到b
{
String[] se = range.split("-");
start = Long.parseLong(se[0]);
end = Long.parseLong(se[1]);
contentLength = end-start+1;
}
return new RangeSettings(start,end,contentLength,len);
}
}
Range封装
Java代码 复制代码 收藏代码
public class RangeSettings{
private long start;
private long end;
private long contentLength;
private long totalLength;
private boolean range;
public RangeSettings(){
super();
}
public RangeSettings(long start, long end, long contentLength,long totalLength) {
this.start = start;
this.end = end;
this.contentLength = contentLength;
this.totalLength = totalLength;
this.range = true;
}
public RangeSettings(long totalLength) {
this.totalLength = totalLength;
}
public long getStart() {
return start;
}
public void setStart(long start) {
this.start = start;
}
public long getEnd() {
return end;
}
public void setEnd(long end) {
this.end = end;
}
public long getContentLength() {
return contentLength;
}
public void setContentLength(long contentLength) {
this.contentLength = contentLength;
}
public long getTotalLength() {
return totalLength;
}
public void setTotalLength(long totalLength) {
this.totalLength = totalLength;
}
public boolean isRange() {
return range;
}
}
public class RangeSettings{
private long start;
private long end;
private long contentLength;
private long totalLength;
private boolean range;
public RangeSettings(){
super();
}
public RangeSettings(long start, long end, long contentLength,long totalLength) {
this.start = start;
this.end = end;
this.contentLength = contentLength;
this.totalLength = totalLength;
this.range = true;
}
public RangeSettings(long totalLength) {
this.totalLength = totalLength;
}
public long getStart() {
return start;
}
public void setStart(long start) {
this.start = start;
}
public long getEnd() {
return end;
}
public void setEnd(long end) {
this.end = end;
}
public long getContentLength() {
return contentLength;
}
public void setContentLength(long contentLength) {
this.contentLength = contentLength;
}
public long getTotalLength() {
return totalLength;
}
public void setTotalLength(long totalLength) {
this.totalLength = totalLength;
}
public boolean isRange() {
return range;
}
}
IO流相关处理工具类
Java代码 复制代码 收藏代码
import java.io.InputStream;
public class IoUtil {
public static String setContentType(String returnFileName){
String contentType = "application/octet-stream";
if (returnFileName.lastIndexOf(".") < 0)
return contentType;
returnFileName = returnFileName.toLowerCase();
returnFileName = returnFileName.substring(returnFileName.lastIndexOf(".")+1);
if (returnFileName.equals("html") || returnFileName.equals("htm") || returnFileName.equals("shtml")){
contentType = "text/html";
} else if (returnFileName.equals("css")){
contentType = "text/css";
} else if (returnFileName.equals("xml")){
contentType = "text/xml";
} else if (returnFileName.equals("gif")){
contentType = "image/gif";
} else if (returnFileName.equals("jpeg") || returnFileName.equals("jpg")){
contentType = "image/jpeg";
} else if (returnFileName.equals("js")){
contentType = "application/x-javascript";
} else if (returnFileName.equals("atom")){
contentType = "application/atom+xml";
} else if (returnFileName.equals("rss")){
contentType = "application/rss+xml";
} else if (returnFileName.equals("mml")){
contentType = "text/mathml";
} else if (returnFileName.equals("txt")){
contentType = "text/plain";
} else if (returnFileName.equals("jad")){
contentType = "text/vnd.sun.j2me.app-descriptor";
} else if (returnFileName.equals("wml")){
contentType = "text/vnd.wap.wml";
} else if (returnFileName.equals("htc")){
contentType = "text/x-component";
} else if (returnFileName.equals("png")){
contentType = "image/png";
} else if (returnFileName.equals("tif") || returnFileName.equals("tiff")){
contentType = "image/tiff";
} else if (returnFileName.equals("wbmp")){
contentType = "image/vnd.wap.wbmp";
} else if (returnFileName.equals("ico")){
contentType = "image/x-icon";
} else if (returnFileName.equals("jng")){
contentType = "image/x-jng";
} else if (returnFileName.equals("bmp")){
contentType = "image/x-ms-bmp";
} else if (returnFileName.equals("svg")){
contentType = "image/svg+xml";
} else if (returnFileName.equals("jar") || returnFileName.equals("var") || returnFileName.equals("ear")){
contentType = "application/java-archive";
} else if (returnFileName.equals("doc")){
contentType = "application/msword";
} else if (returnFileName.equals("pdf")){
contentType = "application/pdf";
} else if (returnFileName.equals("rtf")){
contentType = "application/rtf";
} else if (returnFileName.equals("xls")){
contentType = "application/vnd.ms-excel";
} else if (returnFileName.equals("ppt")){
contentType = "application/vnd.ms-powerpoint";
} else if (returnFileName.equals("7z")){
contentType = "application/x-7z-compressed";
} else if (returnFileName.equals("rar")){
contentType = "application/x-rar-compressed";
} else if (returnFileName.equals("swf")){
contentType = "application/x-shockwave-flash";
} else if (returnFileName.equals("rpm")){
contentType = "application/x-redhat-package-manager";
} else if (returnFileName.equals("der") || returnFileName.equals("pem") || returnFileName.equals("crt")){
contentType = "application/x-x509-ca-cert";
} else if (returnFileName.equals("xhtml")){
contentType = "application/xhtml+xml";
} else if (returnFileName.equals("zip")){
contentType = "application/zip";
} else if (returnFileName.equals("mid") || returnFileName.equals("midi") || returnFileName.equals("kar")){
contentType = "audio/midi";
} else if (returnFileName.equals("mp3")){
contentType = "audio/mpeg";
} else if (returnFileName.equals("ogg")){
contentType = "audio/ogg";
} else if (returnFileName.equals("m4a")){
contentType = "audio/x-m4a";
} else if (returnFileName.equals("ra")){
contentType = "audio/x-realaudio";
} else if (returnFileName.equals("3gpp") || returnFileName.equals("3gp")){
contentType = "video/3gpp";
} else if (returnFileName.equals("mp4") ){
contentType = "video/mp4";
} else if (returnFileName.equals("mpeg") || returnFileName.equals("mpg") ){
contentType = "video/mpeg";
} else if (returnFileName.equals("mov")){
contentType = "video/quicktime";
} else if (returnFileName.equals("flv")){
contentType = "video/x-flv";
} else if (returnFileName.equals("m4v")){
contentType = "video/x-m4v";
} else if (returnFileName.equals("mng")){
contentType = "video/x-mng";
} else if (returnFileName.equals("asx") || returnFileName.equals("asf")){
contentType = "video/x-ms-asf";
} else if (returnFileName.equals("wmv")){
contentType = "video/x-ms-wmv";
} else if (returnFileName.equals("avi")){
contentType = "video/x-msvideo";
}
return contentType;
}
// UTF8转码
public static String toUtf8String(String s) {
StringBuffer sb = new StringBuffer();
int len = s.toCharArray().length;
for (int i = 0; i < len; i++) {
char c = s.charAt(i);
if (c >= 0 && c <= 255) {
sb.append(c);
} else {
byte[] b;
try {
b = Character.toString(c).getBytes("utf-8");
} catch (Exception ex) {
System.out.println(ex);
b = new byte[0];
}
for (int j = 0; j < b.length; j++) {
int k = b[j];
if (k < 0)
k += 256;
sb.append("%" + Integer.toHexString(k).toUpperCase());
}
}
}
String s_utf8 = sb.toString();
sb.delete(0, sb.length());
sb.setLength(0);
sb = null;
return s_utf8;
}
public static InputStream skipFully(InputStream in,long howMany)throws Exception{
long remainning = howMany;
long len = 0;
while(remainning>0){
len = in.skip(len);
remainning -= len;
}
return in;
}
}
import java.io.InputStream;
public class IoUtil {
public static String setContentType(String returnFileName){
String contentType = "application/octet-stream";
if (returnFileName.lastIndexOf(".") < 0)
return contentType;
returnFileName = returnFileName.toLowerCase();
returnFileName = returnFileName.substring(returnFileName.lastIndexOf(".")+1);
if (returnFileName.equals("html") || returnFileName.equals("htm") || returnFileName.equals("shtml")){
contentType = "text/html";
} else if (returnFileName.equals("css")){
contentType = "text/css";
} else if (returnFileName.equals("xml")){
contentType = "text/xml";
} else if (returnFileName.equals("gif")){
contentType = "image/gif";
} else if (returnFileName.equals("jpeg") || returnFileName.equals("jpg")){
contentType = "image/jpeg";
} else if (returnFileName.equals("js")){
contentType = "application/x-javascript";
} else if (returnFileName.equals("atom")){
contentType = "application/atom+xml";
} else if (returnFileName.equals("rss")){
contentType = "application/rss+xml";
} else if (returnFileName.equals("mml")){
contentType = "text/mathml";
} else if (returnFileName.equals("txt")){
contentType = "text/plain";
} else if (returnFileName.equals("jad")){
contentType = "text/vnd.sun.j2me.app-descriptor";
} else if (returnFileName.equals("wml")){
contentType = "text/vnd.wap.wml";
} else if (returnFileName.equals("htc")){
contentType = "text/x-component";
} else if (returnFileName.equals("png")){
contentType = "image/png";
} else if (returnFileName.equals("tif") || returnFileName.equals("tiff")){
contentType = "image/tiff";
} else if (returnFileName.equals("wbmp")){
contentType = "image/vnd.wap.wbmp";
} else if (returnFileName.equals("ico")){
contentType = "image/x-icon";
} else if (returnFileName.equals("jng")){
contentType = "image/x-jng";
} else if (returnFileName.equals("bmp")){
contentType = "image/x-ms-bmp";
} else if (returnFileName.equals("svg")){
contentType = "image/svg+xml";
} else if (returnFileName.equals("jar") || returnFileName.equals("var") || returnFileName.equals("ear")){
contentType = "application/java-archive";
} else if (returnFileName.equals("doc")){
contentType = "application/msword";
} else if (returnFileName.equals("pdf")){
contentType = "application/pdf";
} else if (returnFileName.equals("rtf")){
contentType = "application/rtf";
} else if (returnFileName.equals("xls")){
contentType = "application/vnd.ms-excel";
} else if (returnFileName.equals("ppt")){
contentType = "application/vnd.ms-powerpoint";
} else if (returnFileName.equals("7z")){
contentType = "application/x-7z-compressed";
} else if (returnFileName.equals("rar")){
contentType = "application/x-rar-compressed";
} else if (returnFileName.equals("swf")){
contentType = "application/x-shockwave-flash";
} else if (returnFileName.equals("rpm")){
contentType = "application/x-redhat-package-manager";
} else if (returnFileName.equals("der") || returnFileName.equals("pem") || returnFileName.equals("crt")){
contentType = "application/x-x509-ca-cert";
} else if (returnFileName.equals("xhtml")){
contentType = "application/xhtml+xml";
} else if (returnFileName.equals("zip")){
contentType = "application/zip";
} else if (returnFileName.equals("mid") || returnFileName.equals("midi") || returnFileName.equals("kar")){
contentType = "audio/midi";
} else if (returnFileName.equals("mp3")){
contentType = "audio/mpeg";
} else if (returnFileName.equals("ogg")){
contentType = "audio/ogg";
} else if (returnFileName.equals("m4a")){
contentType = "audio/x-m4a";
} else if (returnFileName.equals("ra")){
contentType = "audio/x-realaudio";
} else if (returnFileName.equals("3gpp") || returnFileName.equals("3gp")){
contentType = "video/3gpp";
} else if (returnFileName.equals("mp4") ){
contentType = "video/mp4";
} else if (returnFileName.equals("mpeg") || returnFileName.equals("mpg") ){
contentType = "video/mpeg";
} else if (returnFileName.equals("mov")){
contentType = "video/quicktime";
} else if (returnFileName.equals("flv")){
contentType = "video/x-flv";
} else if (returnFileName.equals("m4v")){
contentType = "video/x-m4v";
} else if (returnFileName.equals("mng")){
contentType = "video/x-mng";
} else if (returnFileName.equals("asx") || returnFileName.equals("asf")){
contentType = "video/x-ms-asf";
} else if (returnFileName.equals("wmv")){
contentType = "video/x-ms-wmv";
} else if (returnFileName.equals("avi")){
contentType = "video/x-msvideo";
}
return contentType;
}
// UTF8转码
public static String toUtf8String(String s) {
StringBuffer sb = new StringBuffer();
int len = s.toCharArray().length;
for (int i = 0; i < len; i++) {
char c = s.charAt(i);
if (c >= 0 && c <= 255) {
sb.append(c);
} else {
byte[] b;
try {
b = Character.toString(c).getBytes("utf-8");
} catch (Exception ex) {
System.out.println(ex);
b = new byte[0];
}
for (int j = 0; j < b.length; j++) {
int k = b[j];
if (k < 0)
k += 256;
sb.append("%" + Integer.toHexString(k).toUpperCase());
}
}
}
String s_utf8 = sb.toString();
sb.delete(0, sb.length());
sb.setLength(0);
sb = null;
return s_utf8;
}
public static InputStream skipFully(InputStream in,long howMany)throws Exception{
long remainning = howMany;
long len = 0;
while(remainning>0){
len = in.skip(len);
remainning -= len;
}
return in;
}
}
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ArcSyncHttpDownloadServlet 源代码： [java] view plaincopyprint? 01.package com.defonds.cds.common; 02. 03.import java.io.BufferedOutputStream; 04.import java.io.File; 05.import java.io.IOException; 06.import java.io.OutputStream; 07.import java.io.RandomAccessFile; 08. 09.import javax.servlet.ServletException; 10.import javax.servlet.http.HttpServlet; 11.import javax.servlet.http.HttpServletRequest; 12.import javax.servlet.http.HttpServletResponse; 13. 14.import org.apache.commons.logging.Log; 15.import org.apache.commons.logging.LogFactory; 16. 17.import com.defonds.cds.common.util.CommonUtil; 18. 19.//HTTP 断点续传 demo（客户端测试工具：快车、迅雷） 20.public class ArcSyncHttpDownloadServlet extends HttpServlet { 21. private static final long serialVersionUID = 1L; 22. final static Log log = LogFactory.getLog(ArcSyncHttpDownloadServlet.class); 23. 24. @Override 25. protected void doGet(HttpServletRequest req, HttpServletResponse resp) 26. throws ServletException, IOException { 27. this.doPost(req, resp); 28. } 29. 30. @Override 31. protected void doPost(HttpServletRequest request, HttpServletResponse response) { 32. File downloadFile = new File("D:/defonds/book/pattern/SteveJobsZH.pdf");//要下载的文件 33. long fileLength = downloadFile.length();//记录文件大小 34. long pastLength = 0;//记录已下载文件大小 35. int rangeSwitch = 0;//0：从头开始的全文下载；1：从某字节开始的下载（bytes=27000-）；2：从某字节开始到某字节结束的下载（bytes=27000-39000） 36. long toLength = 0;//记录客户端需要下载的字节段的最后一个字节偏移量（比如bytes=27000-39000，则这个值是为39000） 37. long contentLength = 0;//客户端请求的字节总量 38. String rangeBytes = "";//记录客户端传来的形如“bytes=27000-”或者“bytes=27000-39000”的内容 39. RandomAccessFile raf = null;//负责读取数据 40. OutputStream os = null;//写出数据 41. OutputStream out = null;//缓冲 42. byte b[] = new byte[1024];//暂存容器 43. 44. if (request.getHeader("Range") != null) {// 客户端请求的下载的文件块的开始字节 45. response.setStatus(javax.servlet.http.HttpServletResponse.SC_PARTIAL_CONTENT); 46. log.info("request.getHeader("Range")=" + request.getHeader("Range")); 47. rangeBytes = request.getHeader("Range").replaceAll("bytes=", ""); 48. if (rangeBytes.indexOf('-') == rangeBytes.length() - 1) {//bytes=969998336- 49. rangeSwitch = 1; 50. rangeBytes = rangeBytes.substring(0, rangeBytes.indexOf('-')); 51. pastLength = Long.parseLong(rangeBytes.trim()); 52. contentLength = fileLength - pastLength + 1;//客户端请求的是 969998336 之后的字节 53. } else {//bytes=1275856879-1275877358 54. rangeSwitch = 2; 55. String temp0 = rangeBytes.substring(0,rangeBytes.indexOf('-')); 56. String temp2 = rangeBytes.substring(rangeBytes.indexOf('-') + 1, rangeBytes.length()); 57. pastLength = Long.parseLong(temp0.trim());//bytes=1275856879-1275877358，从第 1275856879 个字节开始下载 58. toLength = Long.parseLong(temp2);//bytes=1275856879-1275877358，到第 1275877358 个字节结束 59. contentLength = toLength - pastLength + 1;//客户端请求的是 1275856879-1275877358 之间的字节 60. } 61. } else {//从开始进行下载 62. contentLength = fileLength;//客户端要求全文下载 63. } 64. 65. /** 66. * 如果设设置了Content-Length，则客户端会自动进行多线程下载。如果不希望支持多线程，则不要设置这个参数。 67. * 响应的格式是: 68. * Content-Length: [文件的总大小] - [客户端请求的下载的文件块的开始字节] 69. * ServletActionContext.getResponse().setHeader("Content-Length", 70. * new Long(file.length() - p).toString()); 71. */ 72. response.reset();//告诉客户端允许断点续传多线程连接下载,响应的格式是:Accept-Ranges: bytes 73. response.setHeader("Accept-Ranges", "bytes");//如果是第一次下,还没有断点续传,状态是默认的 200,无需显式设置;响应的格式是:HTTP/1.1 200 OK 74. if (pastLength != 0) { 75. //不是从最开始下载, 76. //响应的格式是: 77. //Content-Range: bytes [文件块的开始字节]-[文件的总大小 - 1]/[文件的总大小] 78. log.info("----------------------------不是从开始进行下载！服务器即将开始断点续传..."); 79. switch (rangeSwitch) { 80. case 1 : {//针对 bytes=27000- 的请求 81. String contentRange = new StringBuffer("bytes ").append(new Long(pastLength).toString()).append("-").append(new Long(fileLength - 1).toString()).append("/").append(new Long(fileLength).toString()).toString(); 82. response.setHeader("Content-Range", contentRange); 83. break; 84. } 85. case 2 : {//针对 bytes=27000-39000 的请求 86. String contentRange = rangeBytes + "/" + new Long(fileLength).toString(); 87. response.setHeader("Content-Range", contentRange); 88. break; 89. } 90. default : { 91. break; 92. } 93. } 94. } else { 95. //是从开始下载 96. log.info("----------------------------是从开始进行下载！"); 97. } 98. 99. try { 100. response.addHeader("Content-Disposition", "attachment; filename="" + downloadFile.getName() + """); 101. response.setContentType( CommonUtil.setContentType(downloadFile.getName()));// set the MIME type. 102. response.addHeader("Content-Length", String.valueOf(contentLength)); 103. os = response.getOutputStream(); 104. out = new BufferedOutputStream(os); 105. raf = new RandomAccessFile(downloadFile, "r"); 106. try { 107. switch (rangeSwitch) { 108. case 0 : {//普通下载，或者从头开始的下载 109. //同1 110. } 111. case 1 : {//针对 bytes=27000- 的请求 112. raf.seek(pastLength);//形如 bytes=969998336- 的客户端请求，跳过 969998336 个字节 113. int n = 0; 114. while ((n = raf.read(b, 0, 1024)) != -1) { 115. out.write(b, 0, n); 116. } 117. break; 118. } 119. case 2 : {//针对 bytes=27000-39000 的请求 120. raf.seek(pastLength - 1);//形如 bytes=1275856879-1275877358 的客户端请求，找到第 1275856879 个字节 121. int n = 0; 122. long readLength = 0;//记录已读字节数 123. while (readLength <= contentLength - 1024) {//大部分字节在这里读取 124. n = raf.read(b, 0, 1024); 125. readLength += 1024; 126. out.write(b, 0, n); 127. } 128. if (readLength <= contentLength) {//余下的不足 1024 个字节在这里读取 129. n = raf.read(b, 0, (int)(contentLength - readLength)); 130. out.write(b, 0, n); 131. } 132.// 133.// raf.seek(pastLength);//形如 bytes=1275856879-1275877358 的客户端请求，找到第 1275856879 个字节 134.// while (raf.getFilePointer() < toLength) { 135.// out.write(raf.read()); 136.// } 137. break; 138. } 139. default : { 140. break; 141. } 142. } 143. out.flush(); 144. } catch(IOException ie) { 145. /** 146. * 在写数据的时候， 147. * 对于 ClientAbortException 之类的异常， 148. * 是因为客户端取消了下载，而服务器端继续向浏览器写入数据时， 149. * 抛出这个异常，这个是正常的。 150. * 尤其是对于迅雷这种吸血的客户端软件， 151. * 明明已经有一个线程在读取 bytes=1275856879-1275877358， 152. * 如果短时间内没有读取完毕，迅雷会再启第二个、第三个。。。线程来读取相同的字节段， 153. * 直到有一个线程读取完毕，迅雷会 KILL 掉其他正在下载同一字节段的线程， 154. * 强行中止字节读出，造成服务器抛 ClientAbortException。 155. * 所以，我们忽略这种异常 156. */ 157. //ignore 158. } 159. } catch (Exception e) { 160. log.error(e.getMessage(), e); 161. } finally { 162. if (out != null) { 163. try { 164. out.close(); 165. } catch (IOException e) { 166. log.error(e.getMessage(), e); 167. } 168. } 169. if (raf != null) { 170. try { 171. raf.close(); 172. } catch (IOException e) { 173. log.error(e.getMessage(), e); 174. } 175. } 176. } 177. } 178.} ArcSyncHttpDownloadServlet 的 web.xml 配置清单： [html] view plaincopyprint? 01. <!-- HTTP 断点续传 demo:127.0.0.1/cds/http --> 02.<servlet> 03. <servlet-name>httpServlet</servlet-name> 04. <servlet-class>com.defonds.cds.common.ArcSyncHttpDownloadServlet</servlet-class> 05.</servlet> 06.<servlet-mapping> 07. <servlet-name>httpServlet</servlet-name> 08. <url-pattern>/http</url-pattern> 09.</servlet-mapping> ArcSyncHttpDownloadServlet 调用到的工具类 com.defonds.cds.common.util.CommonUtil 源代码： [java] view plaincopyprint? 01.package com.defonds.cds.common.util; 02. 03.public class CommonUtil { 04. 05. public static String setContentType(String returnFileName){ 06. String contentType = "application/octet-stream"; 07. if (returnFileName.lastIndexOf(".") < 0) 08. return contentType; 09. returnFileName = returnFileName.toLowerCase(); 10. returnFileName = returnFileName.substring(returnFileName.lastIndexOf(".")+1); 11. 12. if (returnFileName.equals("html") || returnFileName.equals("htm") || returnFileName.equals("shtml")){ 13. contentType = "text/html"; 14. } else if (returnFileName.equals("css")){ 15. contentType = "text/css"; 16. } else if (returnFileName.equals("xml")){ 17. contentType = "text/xml"; 18. } else if (returnFileName.equals("gif")){ 19. contentType = "image/gif"; 20. } else if (returnFileName.equals("jpeg") || returnFileName.equals("jpg")){ 21. contentType = "image/jpeg"; 22. } else if (returnFileName.equals("js")){ 23. contentType = "application/x-javascript"; 24. } else if (returnFileName.equals("atom")){ 25. contentType = "application/atom+xml"; 26. } else if (returnFileName.equals("rss")){ 27. contentType = "application/rss+xml"; 28. } else if (returnFileName.equals("mml")){ 29. contentType = "text/mathml"; 30. } else if (returnFileName.equals("txt")){ 31. contentType = "text/plain"; 32. } else if (returnFileName.equals("jad")){ 33. contentType = "text/vnd.sun.j2me.app-descriptor"; 34. } else if (returnFileName.equals("wml")){ 35. contentType = "text/vnd.wap.wml"; 36. } else if (returnFileName.equals("htc")){ 37. contentType = "text/x-component"; 38. } else if (returnFileName.equals("png")){ 39. contentType = "image/png"; 40. } else if (returnFileName.equals("tif") || returnFileName.equals("tiff")){ 41. contentType = "image/tiff"; 42. } else if (returnFileName.equals("wbmp")){ 43. contentType = "image/vnd.wap.wbmp"; 44. } else if (returnFileName.equals("ico")){ 45. contentType = "image/x-icon"; 46. } else if (returnFileName.equals("jng")){ 47. contentType = "image/x-jng"; 48. } else if (returnFileName.equals("bmp")){ 49. contentType = "image/x-ms-bmp"; 50. } else if (returnFileName.equals("svg")){ 51. contentType = "image/svg+xml"; 52. } else if (returnFileName.equals("jar") || returnFileName.equals("var") || returnFileName.equals("ear")){ 53. contentType = "application/java-archive"; 54. } else if (returnFileName.equals("doc")){ 55. contentType = "application/msword"; 56. } else if (returnFileName.equals("pdf")){ 57. contentType = "application/pdf"; 58. } else if (returnFileName.equals("rtf")){ 59. contentType = "application/rtf"; 60. } else if (returnFileName.equals("xls")){ 61. contentType = "application/vnd.ms-excel"; 62. } else if (returnFileName.equals("ppt")){ 63. contentType = "application/vnd.ms-powerpoint"; 64. } else if (returnFileName.equals("7z")){ 65. contentType = "application/x-7z-compressed"; 66. } else if (returnFileName.equals("rar")){ 67. contentType = "application/x-rar-compressed"; 68. } else if (returnFileName.equals("swf")){ 69. contentType = "application/x-shockwave-flash"; 70. } else if (returnFileName.equals("rpm")){ 71. contentType = "application/x-redhat-package-manager"; 72. } else if (returnFileName.equals("der") || returnFileName.equals("pem") || returnFileName.equals("crt")){ 73. contentType = "application/x-x509-ca-cert"; 74. } else if (returnFileName.equals("xhtml")){ 75. contentType = "application/xhtml+xml"; 76. } else if (returnFileName.equals("zip")){ 77. contentType = "application/zip"; 78. } else if (returnFileName.equals("mid") || returnFileName.equals("midi") || returnFileName.equals("kar")){ 79. contentType = "audio/midi"; 80. } else if (returnFileName.equals("mp3")){ 81. contentType = "audio/mpeg"; 82. } else if (returnFileName.equals("ogg")){ 83. contentType = "audio/ogg"; 84. } else if (returnFileName.equals("m4a")){ 85. contentType = "audio/x-m4a"; 86. } else if (returnFileName.equals("ra")){ 87. contentType = "audio/x-realaudio"; 88. } else if (returnFileName.equals("3gpp") || returnFileName.equals("3gp")){ 89. contentType = "video/3gpp"; 90. } else if (returnFileName.equals("mp4") ){ 91. contentType = "video/mp4"; 92. } else if (returnFileName.equals("mpeg") || returnFileName.equals("mpg") ){ 93. contentType = "video/mpeg"; 94. } else if (returnFileName.equals("mov")){ 95. contentType = "video/quicktime"; 96. } else if (returnFileName.equals("flv")){ 97. contentType = "video/x-flv"; 98. } else if (returnFileName.equals("m4v")){ 99. contentType = "video/x-m4v"; 100. } else if (returnFileName.equals("mng")){ 101. contentType = "video/x-mng"; 102. } else if (returnFileName.equals("asx") || returnFileName.equals("asf")){ 103. contentType = "video/x-ms-asf"; 104. } else if (returnFileName.equals("wmv")){ 105. contentType = "video/x-ms-wmv"; 106. } else if (returnFileName.equals("avi")){ 107. contentType = "video/x-msvideo"; 108. } 109. 110. return contentType; 111. } 112. 113. 114.}