Spring整合Struts2实现多文件上传及下载

Sping与Struts环境的搭建在前文已经讲述过了，再次就不再做过多介绍了，详情请参考前文《Spring整合Struts2中拦截链与注解的使用
》。接下来进入正题，Struts2的多文件上传步骤。本文仍然沿用Spring框架对Struts2框架进行管理，首先来看web.xml文件：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
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_2_5.xsd"> <display-name></display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>

<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:config/applicationContext-*.xml</param-value>
</context-param>

<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
<init-param>
<param-name>config</param-name>
<param-value>struts-default.xml,struts-plugin.xml,config/struts.xml</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>

为了方便维护，我将一般常用变量放入struts.xml文件，通过include标签将struts-upload.xml文件引入到struts.xml文件中，其配置内容分别如下：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">

<!-- struts.xml文件 -->
<struts>
<include file="config/struts-upload.xml"></include>

<constant name="struts.action.extension" value=","></constant>
<!-- 上传文件是所允许的文件最大值 -->
<constant name="struts.multipart.maxSize" value="40000000"></constant>
<!-- 设置文件上传时的临时文件夹时F盘下的temp文件夹 -->
<constant name="struts.multipart.saveDir" value="F:\\temp"></constant>

</struts>

<!-- struts-upload.xml文件 -->
<struts>
<package name="upload" namespace="/file" extends="struts-default">
<action name="upload" class="uploadAction">
<result name="success">/success.jsp</result>
<result name="error">/error.jsp</result>
<result name="input">/filetoolargeerror.jsp</result>
<param name="maximumSize">1000000</param>
<param name="allowedTypes">text/plain,application/msword,application/vnd.openxmlformats-officedocument.wordprocessingml.document</param>
</action>

<action name="download" class="downloadAction">
<result name="success" type="stream">
<param name="inputName">fileInput</param>
<param name="contentDisposition">attachment;filename="${fileName}"</param>
</result>
</action>
</package>
</struts>

接下来是applicationContext-bean.xml文件，该文件中通过映射将struts-upload.xml文件中的action名称与真实的javabean进行映射：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd" >

<!-- Spring管理Struts2的Action -->
<bean name="uploadAction" class="com.yang.action.UploadAction" scope="prototype"></bean>

<bean name="downloadAction" class="com.yang.action.DownloadAction" scope="prototype"></bean>

</beans>

具体处理文件上传和下载的Action，分别为UploadAction和DownloadAction：

package com.yang.action;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

public class UploadAction extends ActionSupport {

private List<File> uploads;

private List<String> uploadFileName;

private List<String> uploadContentType;

private long maximumSize;

private String allowedTypes;

public List<File> getUpload() {
return uploads;
}

public void setUpload(List<File> uploads) {
this.uploads = uploads;
}

public List<String> getUploadFileName() {
return uploadFileName;
}

public void setUploadFileName(List<String> uploadFileName) {
this.uploadFileName = uploadFileName;
}

public List<String> getUploadContentType() {
return uploadContentType;
}

public void setUploadContentType(List<String> uploadContentType) {
this.uploadContentType = uploadContentType;
}

public long getMaximumSize() {
return maximumSize;
}

public void setMaximumSize(long maximumSize) {
this.maximumSize = maximumSize;
}

public String getAllowedTypes() {
return allowedTypes;
}

public void setAllowedTypes(String allowedTypes) {
this.allowedTypes = allowedTypes;
}

public String execute() throws Exception {
//取得文件上传路径（用于存放上传的文件）
File uploadFile = new File(ServletActionContext.getServletContext().getRealPath("upload"));
//判断上述路径是否存在，如果不存在则创建该路径
if (!uploadFile.exists()) {
uploadFile.mkdir();
}

if(uploads != null){
String[] allowedTypesStr = allowedTypes.split(",");
//将允许的文件类型列表放入List中
List allowedTypesList = new ArrayList();
for(int i = 0;i < allowedTypesStr.length; i++){
allowedTypesList.add(allowedTypesStr[i]);
}

//判断上传文件的类型是否是允许的类型之一
for(int i = 0; i < uploads.size();i++){
if(!allowedTypesList.contains(uploadContentType.get(i))){
System.out.println("上传文件中包含非法文件类型");
ServletActionContext.getServletContext().setAttribute("errorMsg", "上传文件中包含非法文件类型");
return "error";
}
}

//判断文件的大小
for(int i = 0 ;i < uploads.size();i++){

System.out.println(uploads.get(i).length());
// 判断文件长度
if (maximumSize < uploads.get(i).length()) {
ServletActionContext.getServletContext().setAttribute("errorMsg", uploadFileName.get(i)+ "文件过大");
return "error";
}
}

for(int i = 0; i < uploads.size();i++){
// 第一种文件上传的读写方式
FileInputStream input = new FileInputStream(uploads.get(i));
FileOutputStream out = new FileOutputStream(uploadFile + "\\" + uploadFileName.get(i));

try{
byte[] b = new byte[1024];
int m = 0;
while ((m = input.read(b)) > 0) {
out.write(b, 0, m);
}
}catch(Exception e){
e.printStackTrace();
ServletActionContext.getServletContext().setAttribute("errorMsg", uploadFileName.get(i) + "上传过程中发生未知错误，请联系管理员。上传失败！");
return "error";
}finally{
input.close();
out.close();
//删除临时文件
uploads.get(i).delete();
}
}
return "success";
}else{
ServletActionContext.getServletContext().setAttribute("errorMsg", "请选择上传文件");
return "error";
}
}
}

package com.yang.action;

import java.io.InputStream;

import org.apache.struts2.ServletActionContext;

public class DownloadAction {

private InputStream fileInput;

private String fileName;

public InputStream getFileInput() {
return fileInput;
//		return ServletActionContext.getServletContext().getResourceAsStream("upload\\" + fileName);
}

public void setFileInput(InputStream fileInput) {
this.fileInput = fileInput;
}

public String getFileName() {
return fileName;
}

public void setFileName(String fileName) {
this.fileName = fileName;
}

public String execute() throws Exception {
fileInput = ServletActionContext.getServletContext().getResourceAsStream("upload\\" + fileName);
return "success";
}
}

最后是前台界面upload.jsp和download.jsp，其页面代码如下：

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html 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=UTF-8">
<title>upload</title>
</head>
<body>
<form action="file/upload" method="post" enctype="multipart/form-data">
<input type="file" name="upload">
<input type="file" name="upload">
<input type="file" name="upload">
<input type="submit" name="btnUpload" value="上传">
</form>
</body>
</html>

<title>download</title>
</head>
<body>
<a href="file/download?fileName=123.txt">123.txt</a>
</body>
</html>

以上内容为实现多文件上传以及问价下载的实例。在接下来的文章中将会介绍Spring与Hibernate集成的使用。