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 {

	@Override
	public 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-bean
            name="uploadForm"
            type="xxx.xxx.form.UploadForm"/>
    </form-beans>

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