Struts2实现文件上传功能实例解析

Z时代
2024-01-10
分类：IT

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>