问题已经困扰我两天了！那前辈能解决一下小弟感激不尽！
jsp代码 ：
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<FORM METHOD="POST" ACTION="FileUploadServlet" ENCTYPE="multipart/form-data">
<INPUT TYPE="FILE" NAME="FILE1" SIZE="50"><BR>
<INPUT TYPE="SUBMIT" VALUE="Upload">
</FORM>
</body>
</html>
Servlet代码：
package wl;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
public class FileUploadServlet extends HttpServlet {
public FileUploadServlet() {
super();
}
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("111");
final long MAX_SIZE = 3 * 1024 * 1024;// 设置上传文件最大为 3M
// 允许上传的文件格式的列表
final String[] allowedExt = new String[] { "jpg", "jpeg", "gif", "txt",
"doc", "docx", "mp3", "wma", "m4a" };
response.setContentType("text/html");
// 设置字符编码为UTF-8, 这样支持汉字显示
response.setCharacterEncoding("UTF-8");
// 实例化一个硬盘文件工厂,用来配置上传组件ServletFileUpload
DiskFileItemFactory dfif = new DiskFileItemFactory();
dfif.setSizeThreshold(4096);// 设置上传文件时用于临时存放文件的内存大小,这里是4K.多于的部分将临时存在硬盘
dfif.setRepository(new File(request.getRealPath("/")
+ "ImagesUploadTemp"));// 设置存放临时文件的目录,web根目录下的ImagesUploadTemp目录
// 用以上工厂实例化上传组件
ServletFileUpload sfu = new ServletFileUpload(dfif);
// 设置最大上传尺寸
sfu.setSizeMax(MAX_SIZE);
PrintWriter out = response.getWriter();
// 从request得到 所有 上传域的列表
List fileList = null;
try {
fileList = sfu.parseRequest(request);//单步执行每次都会在这里出错
} catch (FileUploadException e) {// 处理文件尺寸过大异常
if (e instanceof SizeLimitExceededException) {
out.println("文件尺寸超过规定大小:" + MAX_SIZE + "字节<p />");
out.println("<a href=\"upload.html\" target=\"_top\">返回</a>");
return;
}
e.printStackTrace();
}
// 没有文件上传
if (fileList == null || fileList.size() == 0) {
out.println("请选择上传文件<p />");
out.println("<a href=\"upload.html\" target=\"_top\">返回</a>");
return;
}
// 得到所有上传的文件
Iterator fileItr = fileList.iterator();
// 循环处理所有文件
while (fileItr.hasNext()) {
FileItem fileItem = null;
String path = null;
long size = 0;
// 得到当前文件
fileItem = (FileItem) fileItr.next();
// 忽略简单form字段而不是上传域的文件域(<input type="text" />等)
if (fileItem == null || fileItem.isFormField()) {
continue;
}
// 得到文件的完整路径
path = fileItem.getName();
// 得到文件的大小
size = fileItem.getSize();
if ("".equals(path) || size == 0) {
out.println("请选择上传文件<p />");
out.println("<a href=\"upload.html\" target=\"_top\">返回</a>");
return;
}
// 得到去除路径的文件名
String t_name = path.substring(path.lastIndexOf("\\") + 1);
// 得到文件的扩展名(无扩展名时将得到全名)
String t_ext = t_name.substring(t_name.lastIndexOf(".") + 1);
// 拒绝接受规定文件格式之外的文件类型
int allowFlag = 0;
int allowedExtCount = allowedExt.length;
for (; allowFlag < allowedExtCount; allowFlag++) {
if (allowedExt[allowFlag].equals(t_ext))
break;
}
if (allowFlag == allowedExtCount) {
out.println("请上传以下类型的文件<p />");
for (allowFlag = 0; allowFlag < allowedExtCount; allowFlag++)
out.println("*." + allowedExt[allowFlag]
+ " ");
out
.println("<p /><a href=\"upload.html\" target=\"_top\">返回</a>");
return;
}
long now = System.currentTimeMillis();
// 根据系统时间生成上传后保存的文件名
String prefix = String.valueOf(now);
// 保存的最终文件完整路径,保存在web根目录下的ImagesUploaded目录下
String u_name = request.getRealPath("/") + "ImagesUploaded/"
+ prefix + "." + t_ext;
try {
// 保存文件
fileItem.write(new File(u_name));
out.println("文件上传成功. 已保存为: " + prefix + "." + t_ext
+ " 文件大小: " + size + "字节<p />");
out.println("<a href=\"upload.html\" target=\"_top\">继续上传</a>");
} catch (Exception e) {
e.printStackTrace();
}
}
}
public void init() throws ServletException {
// Put your code here
}
}
错误页面：
