标签：trim lan 临时 方法 tip 大于 htm over 运行
导入pom依赖：
<!--文件上传-->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.3.3</version>
</dependency>
<!--servlet-api导入高版本的-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
</dependency>FileServlet.java：
package com.it.servlet;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.List;
import java.util.UUID;
public class FileServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
// 判断上传的文件是普通表单还是带文件的表单
if (!ServletFileUpload.isMultipartContent(req)) {
return; //终止方法运行，如果是一个普通文件直接返回；
}
// 创建文件上传的保存路径，最好在WEB-INF下，用户无法直接访问
String uploadPath = this.getServletContext().getRealPath("/WEB-INF/upload");
File uploadFile = new File(uploadPath);
if (!uploadFile.exists()) {
uploadFile.mkdir(); //如国文件不存在就创建一个。
}
//消息提示
String msg = "";
// 缓存临时文件，如果文件大小超过了限至，就转到缓存中，过一段时间后删除，或者提醒用户永久删除
String tempPath = this.getServletContext().getRealPath("/WEB-INF/upload");
File temp = new File(tempPath);
if (!temp.exists()) {
temp.mkdir(); //如国文件不存在就创建一个。
}
// 使用commons-fileupload上传组件实现上传
// 1.创建DiskFileItemFactory对象，处理文件上传l路径或者大小的限至
DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();
/*
// 通过这个工厂的设置一个缓冲区，当文件上传大于这个缓冲区的时候就将它放到临时文件中
diskFileItemFactory.setSizeThreshold(1024*1024); //缓存区大小
diskFileItemFactory.setRepository(temp); //临时文件的保存目录
*/
// 2.获取ServletFileUpload
ServletFileUpload servletFileUpload = new ServletFileUpload(diskFileItemFactory);
//解决上传文件名的中文乱码
servletFileUpload.setHeaderEncoding("UTF-8");
// 3.处理上传文件
List<FileItem> fileItems = null;
try {
fileItems = servletFileUpload.parseRequest(req);
} catch (FileUploadException e) {
e.printStackTrace();
}
//fileItem每一个表单对象
for (FileItem fileItem : fileItems) {
//如果fileitem中封装的是普通输入项的数据
if (fileItem.isFormField()) {
String name = fileItem.getFieldName(); //getFieldName()表单对象的name
//解决普通输入项的数据的中文乱码问题
String value = fileItem.getString("UTF-8");
//value = new String(value.getBytes("iso8859-1"),"UTF-8");
System.out.println(name + "=" + value);
}else {
//======================处理文件==========================//
String uploadFileName = fileItem.getName();
System.out.println(uploadFileName);
if(uploadFileName==null || uploadFileName.trim().equals("")){
continue;
}
//处理获取到的上传文件的文件名的路径部分，只保留文件名部分
uploadFileName = uploadFileName.substring(uploadFileName.lastIndexOf("\\")+1);
//处理获取到的上传文件的后缀名例如.jpg
uploadFileName = uploadFileName.substring(uploadFileName.lastIndexOf(".")+1);
//生成为一个一个识别的通用码
String uuidPath = UUID.randomUUID().toString();
//======================存放地址==========================//
//文件存在的真实路径
String realPath = uploadPath + "/" + uuidPath;
//给每个文件创建一个文件夹
File realFile = new File(realPath);
if (!realFile.exists()){
realFile.mkdir();
}
//======================文件输出==========================//
InputStream inputStream = fileItem.getInputStream();
FileOutputStream fileOutputStream = new FileOutputStream(realPath + "/" + uploadFileName);
byte[] bytes = new byte[1024 * 1024];
int len = 0;
while ((len=inputStream.read(bytes))>0){
fileOutputStream.write(bytes,0,len);
}
fileOutputStream.close();
inputStream.close();
msg = "文件上传成功";
fileItem.delete();
}
msg="文件上传失败";
}
req.setAttribute("msg",msg);
req.getRequestDispatcher("/info.jsp").forward(req, resp);
}
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}web.xml注册servlet
<?xml version="1.0" encoding="UTF-8"?>
<web-app 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_3_0.xsd"
version="3.0"
metadata-complete="true">
<servlet>
<servlet-name>FileServlet</servlet-name>
<servlet-class>com.it.servlet.FileServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>FileServlet</servlet-name>
<url-pattern>/upload.do</url-pattern>
</servlet-mapping>
</web-app>index.jsp:
<%@ page contentType="text/html; charset=UTF-8" language="java" %>
<html>
<body>
<%--get上传文件大小有限制，post没有大小限制.文件上传加一个enctype--%>
<form action="${PageContext.request.contextPath}/upload" enctype="multipart/form-data" method="post">
<input type="text"name="text">
<input type="file" name="file1">
<input type="file" name="file1">
<input type="submit">
</form>
</body>
</html>info.jsp:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
${msg}
</body>
</html>标签：trim lan 临时 方法 tip 大于 htm over 运行
原文地址：https://www.cnblogs.com/DavisSamuel/p/12465290.html
