web_xml:
<?xml version="1.0" encoding="UTF-8" ?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
<servlet-name>up</servlet-name>
<servlet-class>servlet.UPLoadServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>up</servlet-name>
<url-pattern>/upload</url-pattern>
</servlet-mapping>
</web-app>
UPLoadServlet.java:
package servlet;
import java.io.File;
import java.io.IOException;
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.*;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
public class UPLoadServlet extends HttpServlet{
private static final long serialVersionUID = -5370788294495423714L;
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
this.doPost(req, resp);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//System.out.println(request.getParameter("test"));
request.setCharacterEncoding("utf-8");// 设置字符编码为UTF-8, 统一编码，处理出现乱码问题
//response.setContentType("text/html;charset=utf-8");
//response.setCharacterEncoding("utf-8");
boolean isMultipart = ServletFileUpload.isMultipartContent(request);//检查是否是一个文件上传请求
if(isMultipart){
System.out.println("isMultipart");
//实例化一个硬盘文件工厂,用来配置上传组件ServletFileUpload
DiskFileItemFactory factory = new DiskFileItemFactory();
//设置上传文件时用于临时存放文件的内存大小,这里是2K.多于的部分将临时存在硬盘
factory.setSizeThreshold(1024*2);
//设置存放临时文件的目录,web根目录下的ImagesUploadTemp目录
File filetemp = new File("c://file");
if(!filetemp.exists()){
filetemp.mkdir();
}
factory.setRepository(filetemp);//临时文件
//以上两项可通过DiskFileItemFactory构参来创建
//DiskFileItemFactory factory = new DiskFileItemFactory(yourMaxMemorySize, yourTempDirectory);
//用上面的工厂实例化上传组件，
ServletFileUpload upload = new ServletFileUpload(factory);
//upload.setFileItemFactory(factory);
//如果ServletFileUpload实例中不设置上面的Factory则报java.lang.NullPointerException: No FileItemFactory has been set.
//设置最大上传大小 10M
upload.setSizeMax(1024*1024*10);
String name = "";
try {
List items = upload.parseRequest(request); // 得到所有FileItem
Iterator iter = items.iterator();
// 循环处理所有文件
while (iter.hasNext()) {
FileItem item = (FileItem) iter.next();
if (!item.isFormField()) {// 判断是否是表单元素(<input type="text" />单选，多选等)
name = item.getName();// 得到文件的名称
if(name==null || "".equals(name.trim())){
//未选择上传文件
continue;
}
long size = item.getSize();//文件长度
File file = new File("c://file//"+name);
if(file.exists()){
file.delete(); //删除掉已存在同名文件
}
item.write(file); //将文件写入
/**************************************/
//添加将 "c://file//"+name 添加到数据库
}else{
//<input name="test" size="40" type="text">
//String value = item.getString();//表单元素的值,用在非文件上传域中
//String fieldName = item.getFieldName();////表单元素的名称，用在非文件上传域中 **test**
System.out.println(item.getFieldName()+" "+new String(item.getString().getBytes(),"utf-8"));//处理中文问题
}
}
} catch (FileUploadException e) {
//处理文件尺寸过大异常
e.printStackTrace();
} catch (Exception e) {
// 处理文件写入时的异常
System.out.println("Write Error: "+name);
e.printStackTrace();
}
request.getRequestDispatcher("/index.jsp").forward(request, response);
}
}
}
upLoad.html:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<body>
<form method="post" enctype="multipart/form-data" action="/upLoadFile/upload">
<input name="file" type="file" size="15">
<input type="submit" name="SUBMIT" >
</body>
</html>
JAR文件：
servlet-api.jar
standard.jar
jst1.jar
commons-io-1.3.1.jar
commons-fileupload-1.2.1.jar