Struts2框架的下载

动作类代码:

public String down() throws Exception{
        
        //获取application
        ServletContext sc = ServletActionContext.getServletContext();
        //获取服务器上的文件存放的绝对路径
        String realPath = sc.getRealPath("/upload/1.jpg");
        //获取输入流
        inputStream = new FileInputStream(realPath);
        //获取文件名
        fileName = FilenameUtils.getName(realPath);
        //给文件名编码
        fileName = URLEncoder.encode(fileName, "utf-8");
        //获取文件大小
        filelength = inputStream.available();
        return SUCCESS;
    }

"struts.xml"配置文件:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>
    <constant name="struts.devMode" value="true"></constant>
    <constant name="struts.multipart.maxSize" value="1024000"></constant>
    
    <package name="upload" extends="struts-default" namespace="/down">
    
        <action name="down" class="com.rl.action.DownAction" method="down">
            <result name="success" type="stream">
                <param name="inputName">inputStream</param>
                <param name="contentDisposition">attachment;filename=${fileName}</param>
                <param name="contentType">application/octet-stream</param>
                <param name="contentLength">${filelength}</param>
            </result>
        </action>
    </package>
</struts>

服务器中需要有相应的文件:

访问结果: