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Java三大框架之struts的上传文件

2016-07-23 19:28 363 查看
在没有struts之前,想要用Java上传文件还得写很多复杂的代码,利用servlet3.0的新特性,或者在servlet3.0之前比如借助其他的插件,比如commons-fileupload组件,或者其他的。并且代码写得十分复杂。利用struts框架进行上传文件核心代码只需要几行。但是框架用起来感觉有点复杂的就是搭建这个环境了。

首先应该包含核心jar包。这些文件可以从网上下载。我用到的核心jar包如下:



第二步:struts是基于拦截器实现的。因此需要在web.xml里面配置一个拦截器,把控制权交给struts来处理。

<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>/*</url-pattern>
</filter-mapping>第三步:在struts.xml文件中写action的配置
<?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>
<package name="fileAction" extends="struts-default" namespace="/">
<action name="MyfileUpload" class="com.levi.action.FileUpload">
<result name="success">/fileUpload_Success.jsp</result>
<result name="error">/error.jsp</result>
<result name="input">/fileUpload.jsp</result>
</action>
</package>

</struts>第四步前端上传页面代码为:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib prefix="s" uri="/struts-tags" %>
<!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>Insert title here</title>
</head>
<body>
<form action="MyfileUpload" method="post" enctype="multipart/form-data">
<input type="file" name="fileUpload"/><br>
<button type="submit">上传</button>
</form>
<br>
错误信息如下:<s:fielderror></s:fielderror>
</body>
</html>前端上传成功页面如下:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib prefix="s" uri="/struts-tags" %>
<!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>Insert title here</title>
</head>
<body>
文件上传成功<br>
文件名:<s:property value="#session.fileUploadFileName"/><br>
文件类型为:<s:property value="#session.fileUploadContentType"/><br>

</body>
</html>最后编写处理Action的类
package com.levi.action;

import java.io.File;
import java.util.Map;

import org.apache.commons.io.FileUtils;

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

public class FileUpload extends ActionSupport
{

/**
*
*/
private static final long serialVersionUID = 1L;

private File fileUpload;
private String fileUploadFileName;
public File getFileUpload()
{
return fileUpload;
}
public void setFileUpload(File fileUpload)
{
this.fileUpload = fileUpload;
}
public String getFileUploadFileName()
{
return fileUploadFileName;
}
public void setFileUploadFileName(String fileUploadFileName)
{
this.fileUploadFileName = fileUploadFileName;
}
public String getFileUploadContentType()
{
return fileUploadContentType;
}
public void setFileUploadContentType(String fileUploadContentType)
{
this.fileUploadContentType = fileUploadContentType;
}
private String fileUploadContentType;
@Override
public String execute() throws Exception
{
ActionContext actionContext=ActionContext.getContext();
Map<String, Object> session=actionContext.getSession();
session.put("fileUploadFileName", fileUploadFileName);
session.put("fileUploadContentType", fileUploadContentType);
System.out.println("文件名为:"+fileUploadFileName);
System.out.println("文件的类型为:"+fileUploadContentType);
String filePath="d:/upload/"+fileUploadFileName;
File saveFile=new File(filePath);
FileUtils.copyFile(fileUpload, saveFile);
return SUCCESS;
}
}


然后就可以实现上传了。这个绝对简单很多的,只是前面配置有点麻烦。这个只实现了一个单文件的上传,后面可以增加一些配置,比如设定最大文件大小,上传类型等等,下一篇再详细实现
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标签:  Java struts 文件上传