使用struts2进行文件下载以及下载权限控制的例子

本测试有两个模块，一个是文件上上传，一个是文件下载，文件下载的时候会检查是否足有权限，如果没有，就会转发到登录页面，如果有权限，就会直接启动下载程序，给浏览器一个输出流。

下面直接上我的代码：

登录表单


<body>
    <form id="form1" name="form1" method="post" action="login.action">
        <p>
            <label for="textfield">账号</label> <input type="text" name="username"
                id="textfield" />
        </p>
        <p>
            <label for="textfield2">密码</label> <input type="text" name="password"
                id="textfield2" />
        </p>
        <p>
            <input type="submit" name="button" id="button" value="提交" /> <br />
        </p>
    </form>
</body>

上传表单：

 <body>
<form action="upload.action" method="post" enctype="multipart/form-data" name="form1" id="form1">
  <p>
    <label for="fileField"></label>
    <input type="file" name="fileobj" id="fileField" />
  </p>
  <p>
    <input type="submit" name="button" id="button" value="提交" />
    <br />
  </p>
</form>
<a href="showpic.action">查看上传照片</a>
  </body>

查看文件列表：



    <table cellspacing="5" align="center">
        <tr>
            <s:iterator value="#request.photoList" id="photo" status="stu">
                <td><a
                    href="downpic.action?inputFile=<s:property value="photo"/>"> <img
                        src='images/<s:property value="photo"/>' width="400" height="420">
                </a>
                </td>
        </tr>
        <tr>
            </s:iterator>
        </tr>
    </table>

下面是action部分：

package com.updown.Action;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;

import org.apache.commons.io.FilenameUtils;
import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class UploadAction extends ActionSupport {
private File fileobj;
private String fileobjFileName;
private String fileobjContentType;

    /**
     * @return
     */
    public String execute() throws Exception {
        InputStream is = new FileInputStream(fileobj);
        String photoPath = ServletActionContext.getServletContext()
                .getRealPath("/images");
        File filePhotoPath = new File(photoPath);
        if (!filePhotoPath.isDirectory()) {
            filePhotoPath.mkdir();
        }

        String extension = FilenameUtils.getExtension(this.getFileobjFileName());
        String filename = UUID.randomUUID().toString() + "." + extension;

        File tofile = new File(photoPath, filename);

        OutputStream os = new FileOutputStream(tofile);
        byte[] buffer = new byte[1024];
        int length = 0;
        while ((length = is.read(buffer)) > 0) {
            os.write(buffer, 0, length);
        }
        is.close();
        os.close();

        return SUCCESS;
    }



    public File getFileobj() {
        return fileobj;
    }

    public void setFileobj(File fileobj) {
        this.fileobj = fileobj;
    }

    public String getFileobjFileName() {
        return fileobjFileName;
    }

    public void setFileobjFileName(String fileobjFileName) {
        this.fileobjFileName = fileobjFileName;
    }

    public String getFileobjContentType() {
        return fileobjContentType;
    }

    public void setFileobjContentType(String fileobjContentType) {
        this.fileobjContentType = fileobjContentType;
    }

}
package com.updown.Action;
import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class UserAction extends ActionSupport {
private String username;
private String password;
    /**
     * @return
     */
    public String execute() {
        // TODO Auto-generated method stub
        if (username.equals("admin")&&password.equals("admin")){
        ServletActionContext.getRequest().getSession().putValue("user", "admin");
        return SUCCESS;
        }
        return INPUT;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }

}
package com.updown.Action;
import java.io.File;
import java.io.InputStream;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class ShowPicAction extends ActionSupport {
    private String inputFile;
    private InputStream targetFile;

public void setTargetFile(InputStream targetFile) {
        this.targetFile = targetFile;
    }
public InputStream getTargetFile(){
    return ServletActionContext.getServletContext().getResourceAsStream("/images/"+inputFile);
}
    /**
     * @return
     */
    public String execute() {
        String photoPath = ServletActionContext.getServletContext()
                .getRealPath("/images");
        File fphotoPath = new File(photoPath);
        String[] photoList = fphotoPath.list();
        HttpServletRequest request = ServletActionContext.getRequest();
        request.setAttribute("photoList", photoList);
        return SUCCESS;
    }
    public String downfile(){
        String user = (String) ServletActionContext.getRequest().getSession().getAttribute("user");
if (user!=null&&user.equals("admin"))
        return SUCCESS;
return LOGIN;


    }
    public String getInputFile() {
        return inputFile;
    }
    public void setInputFile(String inputFile) {
        this.inputFile = inputFile;
    }

}

struts-xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd">
<struts>

    <package name="default" extends="struts-default">
            <default-action-ref name="download"></default-action-ref>

        <action name="login" class="com.updown.Action.UserAction">
            <result name="success">/upload.jsp</result>
            <result name="input">/login.jsp</result>
        </action>
        <action name="upload" class="com.updown.Action.UploadAction">
            <result name="success">/upload.jsp</result>
        </action>
        <action name="showpic"
            class="com.updown.Action.ShowPicAction">
            <result name="success">/index.jsp</result>
        </action>
        <action name="downpic" class="com.updown.Action.ShowPicAction"
            method="downfile">

            <result name="success" type="stream">
                <param name="contentType">
                    application/octet-stream
                </param>
                <param name="inputName">targetFile</param>
                <param name="bufferSize">4096</param>
                <param name="contentDisposition">
                    filename=&quot;download.file&quot;
                </param>
            </result>

            <result name="login">/login.jsp</result>
        </action></package></struts>
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原文地址：https://www.cnblogs.com/mrcharles/p/11879885.html