Struts2实现文件上传功能实例解析

2019-11-26 13:17:57

字体：大中小

来源：转载

供稿：网友

一、搭建struts2环境

在myeclipse下，右击项目->MyEclipse->Project Facets->install Apache Struts2。

如要自己搭建，需下载struts2包，写struts.xml配置文件。

web.xml文件配置如下：

<filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>*.action</url-pattern> </filter-mapping>

二、文件上传

1.前台页面：

上传页面：

<body> <form action="upload.action" method="post" enctype="multipart/form-data">  <input type="file" name="upload"/>  <input type="submit" value="提交"/>  <br>  ${result} </form> </body>

input name属性与后台命名一致。

上传失败页面：

<body> <h2>上传失败</h2> <s:fielderror></s:fielderror> </body>

需：

<%@ taglib uri="/struts-tags" prefix="s"%>

2.后台Action

主要属性upload，uploadContentType，uploadFileName。

package com.yf.action;import java.io.File;import org.apache.commons.io.FileUtils;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;public class UploadAction extends ActionSupport{ private File upload; private String uploadContentType; private String uploadFileName; private String result; public File getUoload() {  return upload; } public void setUpload(File upload) {  this.upload = upload; } public String getUploadContentType() {  return uploadContentType; } public void setUploadContentType(String uploadContentType) {  this.uploadContentType = uploadContentType; } public String getUploadFileName() {  return uploadFileName; } public void setUploadFileName(String uploadFileName) {  this.uploadFileName = uploadFileName; } public String getResult() {  return result; } public void setResult(String result) {  this.result = result; } @Override public String execute() throws Exception {  String path = ServletActionContext.getServletContext().getRealPath("/images");  File file = new File(path);  if(!file.exists()){   file.mkdir();  }  System.out.println(upload);  FileUtils.copyFile(upload, new File(file,uploadFileName));  result = "上传成功";  return SUCCESS; }}

3.struts.xml文件配置

配置action及配置拦截器限制上传文件的类型及大小。

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd"><struts> <constant name="struts.enable.DynamicMethodInvocation" value="false"/> <constant name="struts.devMode" value="true"/> <constant name="struts.multipart.saveDir" value="/tmp"/> <constant name="struts.custom.i18n.resources" value="app"></constant> <package name="default" namespace="/" extends="struts-default">  <action name="upload" class="com.yf.action.UploadAction">  <result>/index.jsp</result>  <result name="input">/error.jsp</result>  <!-- 配置拦截器限制上传文件的类型及大小 -->  <interceptor-ref name="fileUpload">   <param name="allowedTypes">image/bmp,image/x-png,image/gif,image/jpeg</param>   <param name="maximumSize">2M</param>  </interceptor-ref>  <interceptor-ref name="defaultStack"></interceptor-ref>  </action> </package></struts>

4.新建properties文件

文件上传失败信息显示到前台，处理显示出错信息。

这里写图片描述

文件内容如下：

struts.messages.error.file.too/large=/u4E0A/u4F20/u6587/u4EF6/u592A/u5927/u4E86/uFF01struts.messages.error.content.type.not.allowed=/u4E0A/u4F20/u6587/u4EF6/u7C7B/u578B/u4E0D/u7B26/uFF01

即添加：

Name：struts.messages.error.file.too/large

value : 上传文件太大了！

Name : struts.messages.error.content.type.not.allowed

value: 上传文件类型不符！

运行结果如下：

选择jpg图片，大小不超过2M，运行后

这里写图片描述