现在文件的上传，特别是大文件上传，都需要进度条，让客户知道上传进度。
本文简单记录下如何弄进度条，以及一些上传信息，比如文件的大小，上传速度，预计剩余时间等一些相关信息。代码是匆忙下简单写的，一些验证没做，或代码存在一些隐患，不严谨的地方。本文代码只供参考。
进度条的样式多种多样，有些网站弄得非常绚烂漂亮。本文UI端不太懂，只会一些简单的基本的css而已，所以进度条弄得不好看。本文侧重的给读者提供一个参考，一个实现思路而已。
注：由于jQuery版本用的是2.1.1,所以如果跑本例子源码，请用IE9以上或火狐、谷歌浏览器测试。
UploadFileServlet.Java
import java.io.IOException;
import java.util.Date;
import java.util.Map;
import javax.servlet.servletexception;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.fei.util.FileUploadUtil;
public class UploadFileServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest request,HttpServletResponse response)
throws servletexception,IOException {
this.doPost(request,response);
}
public void doPost(HttpServletRequest request,IOException {
try {
long start = System.currentTimeMillis();
System.out.println("开始上传文件........." );
Map<String,String> params = FileUploadUtil.upload(request);
System.out.println("文件上传完成........." );
System.out.println("文件上次用时:"+(System.currentTimeMillis()-start)+"毫秒");
} catch (Exception e) {
e.printstacktrace();
}
}
}
FileUploadUtil.java
import java.io.File;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.ProgressListener;
import org.apache.commons.fileupload.disk.diskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
public class FileUploadUtil {
/**
- 文件上传保存路径
*/
private static final String SAVE_FILEPATH = "/fileupload/";
/** - 文件上传临时保存路径
*/
private static final String SAVE_FILE_TMPPATH = "/fileupload/tmp/";
/** - 上传文件的最大值M
/
private static final int MAX_FILE_SIZE = 1001024*1024;
/** - 文件数据在内存中超过多少M后，就写入临时文件
/
private static final int THRESHOLD_SIZE = 21024*1024;
private static final String ENCODING = "UTF-8";
/**
- 处理文件上传的表单
- 下载文件，并返回文件名称及普通表单域中其它属性值
- 获取文件名
*/
public static Map<String,String> upload(HttpServletRequest request)throws Exception{
Map<String,String> params = new HashMap<String,String>();
String savePath = request.getSession().getServletContext()
.getRealPath(SAVE_FILEPATH)+ File.sep<a href="https://www.jb51.cc/tag/ara/" target="_blank" class="keywords">ara</a>tor;
String savePathTemp = request.getSession().getServletContext()
.getRealPath(SAVE_FILE_TMPPATH)+ File.sep<a href="https://www.jb51.cc/tag/ara/" target="_blank" class="keywords">ara</a>tor;
File saveFileTempDir = new File(savePathTemp);
<a href="https://www.jb51.cc/tag/dis/" target="_blank" class="keywords">dis</a>kFileItemFactory factory = new <a href="https://www.jb51.cc/tag/dis/" target="_blank" class="keywords">dis</a>kFileItemFactory();
//当内存中<a href="https://www.jb51.cc/tag/wenjian/" target="_blank" class="keywords">文件</a>数据达到THRESHOLD_SIZE后，就写入临时<a href="https://www.jb51.cc/tag/wenjian/" target="_blank" class="keywords">文件</a>中，避免<a href="https://www.jb51.cc/tag/shangchuan/" target="_blank" class="keywords">上传</a>大<a href="https://www.jb51.cc/tag/wenjian/" target="_blank" class="keywords">文件</a>时，消化太多内存
factory.setSizeThreshold(THRESHOLD_SIZE);
factory.setRepository(saveFileTempDir);
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setHeaderEncoding(ENCODING);
upload.setSizeMax(MAX_FILE_SIZE);
FileUploadInfo fileUploadInfo = new FileUploadInfo();
upload.setProgressListener(new FileUploadListener(fileUploadInfo));
request.getSession().setAttribute("uploadInfo",fileUploadInfo);
List items = upload.parseRequest(request);
I<a href="https://www.jb51.cc/tag/tera/" target="_blank" class="keywords">tera</a>tor iter = items.i<a href="https://www.jb51.cc/tag/tera/" target="_blank" class="keywords">tera</a>tor();
int fileNum = 1;
while(iter.hasNext()){
FileItem item = (FileItem) iter.next();
if (item.isFormField()) {//普通表单域
p<a href="https://www.jb51.cc/tag/ara/" target="_blank" class="keywords">ara</a>ms.put(item.getFieldName(),item.getString());
} else {
String fileName = item.getName().replace("/","\\");
int i = fileName.lastIndexOf("\\");
fileName = fileName.substring(i+1);
//避免重复
fileName = Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" class="keywords">stem</a>.currentTimeMillis() + fileName;
File uploadedFile = new File(savePath + fileName);
item.write(uploadedFile);
p<a href="https://www.jb51.cc/tag/ara/" target="_blank" class="keywords">ara</a>ms.put("fileName0"+fileNum,fileName);
fileNum ++;
}
}
return p<a href="https://www.jb51.cc/tag/ara/" target="_blank" class="keywords">ara</a>ms; }
}
class FileUploadListener implements ProgressListener{
FileUploadInfo fileUploadInfo = null;
public FileUploadListener(FileUploadInfo fileUploadInfo) {
this.fileUploadInfo = fileUploadInfo;
}
@Override
public void update(long uploadSize,long totalSize,int itemNum) {
this.fileUploadInfo.setTotalSize(totalSize);
this.fileUploadInfo.setUploadSize(uploadSize);
}
}
FileUploadInfo.java
public class FileUploadInfo {
private final int K = 1024;
private final int M = K * 1024;
/**
- 总大小
*/
private long totalSize;
/** - 开始上传时间
*/
private long startTime = System.currentTimeMillis();
/** - 已上传多少
*/
private long uploadSize;
/**
- 上传速度(K/S)
/
public double getUploadSpeed_K(){
long currentTime = System.currentTimeMillis();
long usedTime = currentTime - startTime;
if(usedTime == 0.0){
return 0.0;
}
return getUploadSize_K()/usedTime1000d;
}
/** - 获取已上传百分比
- @return
/
public double getUploadPercent(){
return (getUploadSize()1.00/getTotalSize())*100d;
}
/** - 剩余时间(s)
- @return
*/
public double getRemainTime(){
double speedKB = getUploadSpeed_K();
if(speedKB<= 0.00){
return -1d;
}
return (getTotalSize_K() - getUploadSize_K())/speedKB;
}
/** - 已上传时间
- @return
*/
public double getUseTime(){
return (System.currentTimeMillis() - startTime)/1000d;
}
public long getTotalSize() {
return totalSize;
}
public double getTotalSize_K(){
return getTotalSize()*1.0/K;
}
public double getTotalSize_M(){
return getTotalSize()*1.0/M;
}
public long getUploadSize() {
return uploadSize;
}
public double getUploadSize_K(){
return getUploadSize()/K;
}
public double getUploadSize_M(){
return getUploadSize()/M;
}
public void setTotalSize(long totalSize) {
this.totalSize = totalSize;
}
public void setUploadSize(long uploadSize) {
this.uploadSize = uploadSize;
}
private String double2String(double d){
return String.format("%.2f",d);
}
public String toString(){
return "{"+
"'totalSize':'"+double2String(getTotalSize_M())+"M',"+
"'uploadSize':'"+double2String(getUploadSize_M())+"M',"+
"'uploadSpeed':'"+double2String(getUploadSpeed_K())+"KB/s',"+
"'uploadPrecent':'"+double2String(getUploadPercent())+"',"+
"'remainTime':'"+(getRemainTime()<0?"未知":double2String(getRemainTime()))+"s"+"',"+
"'useTime':'"+double2String(getUseTime())+"s' "+
"}";
}
}
UploadFileProgressServlet.java
import java.io.IOException;
import javax.servlet.servletexception;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.fei.util.FileUploadInfo;
public class UploadFileProgressServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest request,response);
}
public void doPost(HttpServletRequest request,IOException {
String responseContent = "";
Object obj = request.getSession().getAttribute("uploadInfo");
if(obj == null){
responseContent = "{'data':'NoData'}";
}else{
FileUploadInfo uploadInfo = (FileUploadInfo)obj;
responseContent = uploadInfo.toString();
if(uploadInfo.getUploadPercent()== 100.0){
request.getSession().setAttribute("uploadInfo",null);
}
}
Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" class="keywords">stem</a>.out.println("<a href="https://www.jb51.cc/tag/wenjian/" target="_blank" class="keywords">文件</a>上次情况："+responseContent);
response.getWriter().print(responseContent); }
}