Struts中的文件上传

还是代码说话吧。。

首先是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">
	<!-- 解决中文乱码问题 -->
	<filter>
		<filter-name>EncodingFilter</filter-name>
		<filter-class>com.jadyer.util.CharacterEncodingFilter</filter-class>
		<init-param>
			<param-name>encoding</param-name>
			<param-value>UTF-8</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>EncodingFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	
	<servlet>
		<servlet-name>action</servlet-name>
		<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
		<init-param>
			<param-name>config</param-name>
			<param-value>/WEB-INF/struts-config.xml</param-value>
		</init-param>
		<init-param>
			<param-name>debug</param-name>
			<param-value>3</param-value>
		</init-param>
		<init-param>
			<param-name>detail</param-name>
			<param-value>3</param-value>
		</init-param>
		<load-on-startup>0</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>action</servlet-name>
		<url-pattern>*.do</url-pattern>
	</servlet-mapping>
	
	<welcome-file-list>
		<welcome-file>upload.jsp</welcome-file>
	</welcome-file-list>
</web-app>

然后是上传文件的upload.jsp页面

<%@ page language="java" pageEncoding="UTF-8"%>

<form action="upload.do" method="POST" enctype="multipart/form-data">
	标题：<input type="text" name="title" /><br/>
	文件：<input type="file" name="myfile" /><br/>
	<input type="submit" value="上传文件" />
</form>

用于显示文件上传结果的result.jsp页面

<%@ page language="java" pageEncoding="UTF-8"%>

<h2>请到D盘根目录下查看所上传的文件</h2>

<br/>

名称：${uploadForm.title}<br>
文件：${uploadForm.myfile.fileName}

然后是Struts1.x的核心配置文件struts-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN"
"http://struts.apache.org/dtds/struts-config_1_2.dtd">

<struts-config>
	<form-beans>
		<form-bean name="uploadForm" type="com.jadyer.struts.form.UploadForm" />
	</form-beans>

	<action-mappings>
		<action path="/upload"
				type="com.jadyer.struts.action.UploadAction"
				name="uploadForm"
				scope="request">
			<forward name="success" path="/result.jsp" />
		</action>
	</action-mappings>

	<!-- 配置上传参数：设定所上传的文件的最大容量 -->
	<controller maxFileSize="10M" />
</struts-config>

用到的Struts1.x中的ActionForm类

package com.jadyer.struts.form;

import org.apache.struts.action.ActionForm;
import org.apache.struts.upload.FormFile;

/**
 * @see FormFile是由Struts封装的一个接口，它是Struts中专门用来处理文件上传的
 * @see 故Struts上传文件时ActionForm中必须使用FormFile类型来接收上传的文件
 * @see 然后在Action中调用FormFile取得上传文件数据，采用流输出，即完成上传
 */
@SuppressWarnings("serial")
public class UploadForm extends ActionForm {
	private String title;
	private FormFile myfile;
	
	public String getTitle() {
		return title;
	}
	public void setTitle(String title) {
		this.title = title;
	}

	public FormFile getMyfile() {
		return myfile;
	}
	public void setMyfile(FormFile myfile) {
		this.myfile = myfile;
	}
}

处理上传操作的Action类

package com.jadyer.struts.action;

import java.io.FileOutputStream;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.upload.FormFile;

import com.jadyer.struts.form.UploadForm;

public class UploadAction extends Action {
	@Override
	public ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		UploadForm uf = (UploadForm)form;
		
		FormFile myFile = uf.getMyfile();

		if (myFile != null) {
			System.out.println("   Title=" + uf.getTitle());
			System.out.println("FileName=" + myFile.getFileName());
			
			FileOutputStream fos = new FileOutputStream("D://" + myFile.getFileName());
			
			//获取文件内容
			//这种写法并不好。因为这是把上传的内容直接读取出来，然后都存到字节数组中
			//而这部分内容是驻足在内存里的，如果文件过大的，后果可想而知
			//这里只是为了演示Struts的上传功能，更专业的方法是使用其它的上传的插件
			byte[] buf=myFile.getFileData();
			
			fos.write(buf);
			
			//所谓flush的含义是把内存中的东西真正的放到物理上，写到磁盘上
			fos.flush();
			
			fos.close();
		}
		return mapping.findForward("success");
	}
}

最后是用于解决中文乱码问题的Servlet过滤器

package com.jadyer.util;


import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/**
 * 过滤器：设定传输参数编码
 */
public class CharacterEncodingFilter implements Filter {
	private FilterConfig config;
	private String encoding = "ISO8859_1";

	/**
	 * 当过滤器对象被销毁的时候，由Web容器调用该方法
	 * @see 该方法主要用来释放过滤器对象所占用的资源
	 */
	public void destroy() {
		config = null;
	}
	
	/**
	 * 由Web容器在刚生成过滤器对象的时候进行调用，主要用来完成对过滤器的初始化工作
	 * @see 该方法接收一个FilterConfig类型的参数，通过该参数以获得有关当前过滤器的信息
	 * @see 例如：调用FilterConfig的getFilterName()方法可以获得过滤器的名字
	 * @see 例如：调用getServletContext()方法可以获得当前的ServletContext对象
	 * @see 这里主要是用来读取web.xml中设定的<param-name>encoding</param-name>的值
	 */
	public void init(FilterConfig config) throws ServletException {
		this.config = config;
		String s = config.getInitParameter("encoding");
		if (null != s){
			encoding = s;
		}
	}

	/**
	 * doFilter()方法是Filter接口中最核心的方法，完成过滤器的过滤功能
	 */
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
			throws IOException, ServletException {
		request.setCharacterEncoding(encoding); //设定表单参数编码方式
		chain.doFilter(request, response);
	}

}