struts2文件上传与下载

叁歲伎倆 2022-05-25 10:50 221阅读 0赞

# 一、场景 #

完成个人注册图片的上传，并在注册成功后，可以下载自己注册时上传的图片

# 二、实现 #

上传action

import com.opensymphony.xwork2.ActionSupport;
    import org.apache.struts2.ServletActionContext;
    
    import java.io.*;
    import java.util.UUID;
    
    public class FileAction extends ActionSupport {
    
        private User user;
        private File myUpload;//文件
        private String myUploadFileName;//文件名
        private String myUploadContentType;//文档类型
        private String savePath;//存储路径
    
        public User getUser() {
            return user;
        }
    
        public void setUser(User user) {
            this.user = user;
        }
    
        public File getMyUpload() {
            return myUpload;
        }
    
        public void setMyUpload(File myUpload) {
            this.myUpload = myUpload;
        }
    
    
        public String getMyUploadFileName() {
            return myUploadFileName;
        }
    
        public void setMyUploadFileName(String myUploadFileName) {
            this.myUploadFileName = myUploadFileName;
        }
    
        public String getMyUploadContentType() {
            return myUploadContentType;
        }
    
        public void setMyUploadContentType(String myUploadContentType) {
            this.myUploadContentType = myUploadContentType;
        }
    
        //返回文件上传的保存位置
        public String getSavePath() {
            String str = ServletActionContext.getServletContext().getRealPath(savePath);
            return str;
        }
    
        public void setSavePath(String savePath) {
            this.savePath = savePath;
        }
    
        public String upload() throws IOException {
            String newName = UUID.randomUUID().toString();//新的方法名
            String sufix = myUploadFileName.substring(myUploadFileName.lastIndexOf("."));//获取后缀名
            newName+=sufix;//新文件名
            //以服务器的文件保存地址和原文件名建立上传文件输出流
            FileOutputStream fileOutputStream = new FileOutputStream(getSavePath()+"\\"+newName);
            System.out.println(getSavePath());
            myUploadFileName = newName;
            FileInputStream fileInputStream = new FileInputStream(getMyUpload());
            System.out.println(fileOutputStream);
            byte[] bytes = new byte[1024];
            int len = 0;
            while ((len = fileInputStream.read(bytes))>0){
                fileOutputStream.write(bytes,0,len);
            }
            fileOutputStream.close();
            return SUCCESS;
        }
    }

下载action

import com.opensymphony.xwork2.ActionSupport;
    import org.apache.struts2.ServletActionContext;
    
    import java.io.FileNotFoundException;
    import java.io.InputStream;
    
    public class FileDowm extends ActionSupport {
    
        private String name;
        private String contentType;
    
        public String getContentType() {
            return ServletActionContext.getServletContext().getMimeType(name);
        }
    
        public void setContentType(String contentType) {
            this.contentType = contentType;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public InputStream getFile1() throws FileNotFoundException {
            return ServletActionContext.getServletContext().getResourceAsStream("/"+name);
        }
    
        @Override
        public String execute() throws Exception {
            System.out.println(name);
            return SUCCESS;
        }
    }

struts2.xml

<?xml version="1.0" encoding="UTF-8"?>
    
    <!DOCTYPE struts PUBLIC
            "-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
            "http://struts.apache.org/dtds/struts-2.5.dtd">
    
    <struts>
        <package name="user7" extends="struts-default">
            <action name="uplode" class="seven.FileAction" method="upload">
                <param name="savePath">/</param>
                <result name="success">/7/filedownload.jsp</result>
            </action>
            <action name="down" class="seven.FileDowm" method="execute">
                <result name="success" type="stream">
                    <param name="contentType">application/octet-stream;charset=ISO8859-1</param>
                    <param name="contentDisposition">attachment;filename="${name}"</param>
                    <param name="inputName">file1</param>
                    <param name="bufferSize">4096</param>
                </result>
            </action>
        </package>
    </struts>

上传页面：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <%@taglib prefix="s" uri="/struts-tags" %>
    <html>
    <head>
        <title>文件上传</title>
    </head>
    <body>
    <form action="uplode.action" method="post" enctype="multipart/form-data">
        <h2>上传</h2>
        用户名:<input type="text" name="user.name"/>
        密码:<input type="password" name="user.pass"/>
        上传：<<input type="file" name="myUpload">
        <input type="submit" value="提交" />
    </form>
    </body>
    </html>

下载页面：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <%@taglib prefix="s" uri="/struts-tags" %>
    <html>
    <head>
        <title>上传成功</title>
    </head>
    <body>
        <s:property value="myUploadFileName" />
        上传成功：<a href="down.action?name=<s:property value="myUploadFileName"/>">下载</a><br>
        <img src="<s:property value="'/'+myUploadFileName" />">
    </body>
    </html>

# 三、问题与解决 #

**①struts2.xml文件引入失败**

**解决：在设置model处添加（删除后统一添加所有xml）**

**②getRealPath报红线，方法找不到**

ServletActionContext.*getServletContext*().getRealPath(savePath)

**解决**：**去tomcat下找到servlet-api jar包引入到项目中；**

**③动态下载上传的内容xml配置**

<result name="success" type="stream">  
    <param name="contentType">application/octet-stream;charset=ISO8859-1</param>  
    <param name="contentDisposition">attachment;filename="$\{name\}"</param>  
    <param name="inputName">file1</param>  
    <param name="bufferSize">4096</param>  
</result>

**解决：使用ognl表达式动态化，需要action提供get方法！**

**如：file1**

public InputStream getFile1() throws FileNotFoundException \{   
    return ServletActionContext.*getServletContext*().getResourceAsStream("/"\+name);  
\}

**④超链接传参参数不正确**

**解决：name=xx  不加引号！，简单的问题困扰好久**

**⑤idea在上传文件时建立文件夹发现tomacat/webapp下并没有自己部署的项目**

**解决:这是因为idea项目并没有部署到wenapp下，而是有自己的虚拟目录**

** **