重温经典struts1之文件上传-编程知识

重温经典struts1之文件上传

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前言

今天来学习下，每个项目都会有的文件上传功能，看看struts是怎么实现的。

步骤

编写三个jsp页面，一个是跳转到文件上传页面，一个是文件上传用，再一个是上传成功页面
　重点1：form的enctype属性，设置成multipart/form-data
默认的是application/x-www-form-urlencoded

< form action=“upload.do” method=“post” enctype=“multipart/form-data”>

重点2：文件选择框使用 < input type=“file” >来定义

< input type=“file” name=“myfile” >

跳转到文件上传页面(index.jsp)代码如下（示例）：

<%@ page language="java" contentType="text/html; charset=utf-8"pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Insert title here</title>
</head>
<body><a href="upload.jsp">test upload tag</a>
</body>
</html>

文件上传页面(upload.jsp)代码如下（示例）：

<%@ page language="java" contentType="text/html; charset=utf-8"pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Insert title here</title>
</head>
<body><h1>测试Struts上传</h1><hr><p><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="提交"><br></form>
</body>
</html>

上传成功页面(upload_success.jsp)代码如下（示例）：

<%@ page language="java" contentType="text/html; charset=utf-8"pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Insert title here</title>
</head>
<body>上传成功！<br>标题=【${uploadForm.title }】<br>文件名称=【${uploadForm.myfile.fileName }】<br></body>
</html>

编写formbean，将jsp页面的两个输入框的属性，定义到formbean中
　重点：文件选择框的类型使用struts为我们提供的FormFile

import org.apache.struts.upload.FormFile;

private FormFile myfile;

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

formbean代码如下（示例）：

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

编写action，将页面传来的文件流写入指定文件夹
文件选择框的类型使用struts为我们提供的FormFile

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 xxx.xxx.form.UploadForm;public class UploadAction extends Action {@Overridepublic ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request,HttpServletResponse response) throws Exception {UploadForm uf = (UploadForm) form;System.err.println("title=" + uf.getTitle());String fileName = uf.getMyfile().getFileName();System.err.println("fileName=" + fileName);try (FileOutputStream fos = new FileOutputStream("C:/test_upload/" + fileName)) {fos.write(uf.getMyfile().getFileData());fos.flush();}return mapping.findForward("success");}
}

struts-config.xml的配置
　重点：controller 属性
设置单次上传文件的size

<struts-config>中间略<controller maxFileSize="10M"></controller> 中间略
</struts-config>

formbean，action的配置

    <form-beans><form-beanname="uploadForm"type="xxx.xxx.form.UploadForm"/></form-beans><action-mappings><actionpath="/login"type="xxx.xxx.action.LoginAction"name="loginForm"scope="request"></action><actionpath="/upload"type="xxx.xxx.action.UploadAction"name="uploadForm"scope="request"><forward name="success" path="/upload_success.jsp"></forward></action></action-mappings>