纯jsp servlet 实现 upload file功能 博客分类: Java
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2024-03-13 14:16:27
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本篇主要是简单的实现jsp servlet 的上传文件的功能,基于servlet 2.5。
jar依赖:
commons-fileupload/commons-io/servlet-api(commons-fileupload 自动依赖common-io)
pom.xml文件的内容如下:
form 表单的内容:
要点: method必须是post方法,get是不支持文件上传的。
enctype 属性值为:multipart/form-data。
action 的名字可以取了humanable的值就好了。
input的type要设为file,以支持文件类型。
代码如下:
为了能把上传的文件保存起来,我们配置一个保存的路径c:\temp\data, 这个路径必须是真是存在,如果不存在就手动去创建该目录(in web.xml)如下:
整个web.xml如下:
后台的servlet代码如下:
参考链接:http://www.tutorialspoint.com/servlets/servlets-file-uploading.htm
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jar依赖:
commons-fileupload/commons-io/servlet-api(commons-fileupload 自动依赖common-io)
pom.xml文件的内容如下:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.luchenghao.demo</groupId> <artifactId>gridconfig</artifactId> <version>0.0.1-SNAPSHOT</version> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <org.springframework.version>4.1.5.RELEASE</org.springframework.version> </properties> <dependencies> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> </dependency> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3</version> </dependency> </dependencies> </project>
form 表单的内容:
要点: method必须是post方法,get是不支持文件上传的。
enctype 属性值为:multipart/form-data。
action 的名字可以取了humanable的值就好了。
input的type要设为file,以支持文件类型。
代码如下:
<!DOCTYPE title 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>File Uploading Form</title> </head> <h3>File Upload:</h3> Select a file to upload: <br/> <form action="UploadServlet" method="post" enctype="multipart/form-data"> <input type="file" name="file" size="50" /> <br /> <input type="Submit" value="Upload"/> </form> </html>
为了能把上传的文件保存起来,我们配置一个保存的路径c:\temp\data, 这个路径必须是真是存在,如果不存在就手动去创建该目录(in web.xml)如下:
<context-param> <description>Location to store uploaded file</description> <param-name>file-upload</param-name> <param-value> c:\temp\data\ </param-value> </context-param>
整个web.xml如下:
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://java.sun.com/xml/ns/javaee" version="2.5"> <context-param> <description>Location to store uploaded file</description> <param-name>file-upload</param-name> <param-value> c:\temp\data\ </param-value> </context-param> <servlet> <servlet-name>upload</servlet-name> <servlet-class>com.statestreetgx.fcm.core.controller.UploadController</servlet-class> </servlet> <servlet-mapping> <servlet-name>upload</servlet-name> <url-pattern>/UploadServlet</url-pattern> </servlet-mapping> </web-app>
后台的servlet代码如下:
package com.statestreetgx.fcm.core.controller; import java.io.File; 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.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; /** * * @author a574539 */ public class UploadController extends HttpServlet { /** * serialVersionUID */ private static final long serialVersionUID = -3218211616591116540L; private boolean isMultipart; private String filePath; private int maxFileSize = 50 * 1024; private int maxMemSize = 4 * 1024; private File file; public void init() { // Get the file location where it would be stored. filePath = getServletContext().getInitParameter("file-upload"); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, java.io.IOException { // Check that we have a file upload request isMultipart = ServletFileUpload.isMultipartContent(request); response.setContentType("text/html"); java.io.PrintWriter out = response.getWriter(); if (!isMultipart) { out.println("<html>"); out.println("<head>"); out.println("<title>Servlet upload</title>"); out.println("</head>"); out.println("<body>"); out.println("<p>No file uploaded</p>"); out.println("</body>"); out.println("</html>"); return; } DiskFileItemFactory factory = new DiskFileItemFactory(); // maximum size that will be stored in memory factory.setSizeThreshold(maxMemSize); // Location to save data that is larger than maxMemSize. factory.setRepository(new File("c:\\temp")); // Create a new file upload handler ServletFileUpload upload = new ServletFileUpload(factory); // maximum file size to be uploaded. upload.setSizeMax(maxFileSize); try { // Parse the request to get file items. List fileItems = upload.parseRequest(request); // Process the uploaded file items Iterator i = fileItems.iterator(); out.println("<html>"); out.println("<head>"); out.println("<title>Servlet upload</title>"); out.println("</head>"); out.println("<body>"); while (i.hasNext()) { FileItem fi = (FileItem) i.next(); if (!fi.isFormField()) { // Get the uploaded file parameters String fieldName = fi.getFieldName(); String fileName = fi.getName(); String contentType = fi.getContentType(); boolean isInMemory = fi.isInMemory(); long sizeInBytes = fi.getSize(); // Write the file if (fileName.lastIndexOf("\\") >= 0) { file = new File(filePath + fileName.substring(fileName.lastIndexOf("\\"))); } else { file = new File(filePath + fileName.substring(fileName.lastIndexOf("\\") + 1)); } fi.write(file); out.println("Uploaded Filename: " + fileName + "<br>"); } } out.println("</body>"); out.println("</html>"); } catch (Exception ex) { System.out.println(ex); } } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, java.io.IOException { throw new ServletException("GET method used with " + getClass().getName() + ": POST method required."); } // @RequestMapping(value = "upload") // @ResponseBody // public void upload() { // System.out.println("hello"); // } }
参考链接:http://www.tutorialspoint.com/servlets/servlets-file-uploading.htm
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