Javaweb文件上传
Posted DavisSamuel
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文件上传
【 https://github.com/Davis-Samuel/File-Upload/blob/master/JavaWeb%E5%8A%9F%E8%83%BD%E6%89%A9%E5%B1%95.md 】
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>
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