首先Spring是一个非常成熟的J2EE框架，其非入侵式的架构为系统的集成和扩展提供了最大的可能。所以Spring MVC下实现进度监听非常容易，甚至不需要改以前的上传业务代码，具体实现分三个步骤：1、接管CommonsMultipartResolver，重写针对文件上传的请求。2、在第一步中写入监听，以获取上传进度。3、修改上传部分的配置文件。具体见代码1、CommonsMultipartResolver代码
package ;
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/**
* 重写CommonsMultipartResolver以监听文件上传进度
* @author Van
* @date 2012-12-12
*/
public class PJCommonsMultipartResolver extends CommonsMultipartResolver {
private HttpServletRequest request;
protected FileUpload newFileUpload(FileItemFactory fileItemFactory) {
ServletFileUpload upload = new ServletFileUpload(fileItemFactory);
(-1);
if (request != null) {
HttpSession session = ();
PJProgressListener uploadProgressListener = new PJProgressListener(session);
(uploadProgressListener);
}
return upload;
}
public MultipartHttpServletRequest resolveMultipart(
HttpServletRequest request) throws MultipartException {
= request;// 获取到request,要用到session
return (request);
}
@SuppressWarnings("unchecked")
@Override
public MultipartParsingResult parseRequest(HttpServletRequest request) throws MultipartException {
HttpSession session = ();
String encoding = "utf-8";
FileUpload fileUpload = prepareFileUpload(encoding);
PJProgressListener uploadProgressListener = new PJProgressListener(session);
(uploadProgressListener);
try {
List
fileItems = ((ServletFileUpload) fileUpload).parseRequest(request);
return parseFileItems(fileItems, encoding);
}
catch ( ex) {
throw new MaxUploadSizeExceededException((), ex);
}
catch (FileUploadException ex) {
throw new MultipartException("Could not parse multipart servlet request", ex);
}
}
}
PJProgressListener 代码：
package ;
import ;
import ;
import ;
public class PJProgressListener implements ProgressListener{
private HttpSession session;
public PJProgressListener() {
}
public PJProgressListener(HttpSession _session) {
session=_session;
ProgressEntity ps = new ProgressEntity();
("upload_ps", ps);
}
public void update(long pBytesRead, long pContentLength, int pItems) {
ProgressEntity ps = (ProgressEntity) ("upload_ps");
(pBytesRead);
(pContentLength);
(pItems);
//更新
("upload_ps", ps);
}
}
上传进度信息记录实体类：
package ;
/**
* 文件上传进度信息
* @author Van
*
*/
public class ProgressEntity {
private long pBytesRead = 0L;
private long pContentLength = 0L;
private int pItems;
public long getpBytesRead() {
return pBytesRead;
}
public void setpBytesRead(long pBytesRead) {
= pBytesRead;
}
public long getpContentLength() {
return pContentLength;
}
public void setpContentLength(long pContentLength) {
= pContentLength;
}
public int getpItems() {
return pItems;
}
public void setpItems(int pItems) {
= pItems;
}
@Override
public String toString() {
return "ProgressEntity [pBytesRead=" + pBytesRead + ", pContentLength="
+ pContentLength + ", pItems=" + pItems + "]";
}
}
配置文件部分修改：
将替换成：
