通过Struts2的拦截器实现文件上传/上传文件功能

struts.xml配置内容如下：

DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
        "http://struts.apache.org/dtds/struts-2.3.dtd">

    
    
    
    
        
        
            
                /WEB-INF/jsp/uploadform.jsp
            
        
        
            
            
                
                1048576
            
            
            
            
                /WEB-INF/jsp/uploadimage.jsp
            
        
    

BaseAction的代码如下：

package priv.lwx.struts2.fileupload.web;

import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.interceptor.ServletResponseAware;
import org.apache.struts2.interceptor.SessionAware;
import org.apache.struts2.util.ServletContextAware;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Map;

/**
 * description
 *
 * @author liaowenxiong
 * @date 2022/5/9 09:36
 */

public class BaseAction implements SessionAware, ServletRequestAware, ServletResponseAware, ServletContextAware {
  protected Map session;
  protected HttpServletRequest request;
  protected HttpServletResponse response;
  protected ServletContext application;

  @Override
  public void setServletRequest(HttpServletRequest httpServletRequest) {
    this.request = httpServletRequest;
  }

  @Override
  public void setServletResponse(HttpServletResponse httpServletResponse) {
    this.response = httpServletResponse;
  }

  @Override
  public void setSession(Map map) {
    this.session = map;
  }

  @Override
  public void setServletContext(ServletContext context) {
    this.application = context;
  }
}

UploadAction的代码如下：

package priv.lwx.struts2.fileupload.web;

import org.apache.commons.io.IOUtils;

import java.io.*;

/**
 * 实现文件上传功能
 *
 * @author liaowenxiong
 * @date 2022/5/13 15:02
 */

public class UploadAction extends BaseAction {
  /* 注意：属性 xxxFileName、xxxContentType 是固定的写法，
   如在 jsp 页面中的 name=“some”，
   那么在 UploadAction 中对应的 File 属性名为 some。
   但是，如果想取到文件名，那么需要写 someFileName，
   如果想取到文件类型，那么需要写 someContentType。*/
  private File some;
  private String someFileName;
  private String someContentType;
  private String imagePath;

  public String execute() throws IOException {
    System.out.println(application);
    System.out.println("缓存文件路径：" + this.some);
    System.out.println("源文件名：" + someFileName);
    System.out.println("文件类型：" + someContentType);
    // 生成随机的文件名
    String imageName = "file_" + System.currentTimeMillis() + someFileName.substring(someFileName.lastIndexOf("."));
    System.out.println("随机文件名：" + imageName);
    // 这个值在JSP页面中链接到图片时会使用到
    imagePath = "upload-image/" + imageName;
    System.out.println("imagePath:" + imagePath);
    // 获取目录upload-image的绝对路径
    String uploadPath = application.getRealPath("upload-image");
    // 判断目录upload-image是否存在，否则创建该目录
    File file = new File(uploadPath);
    if (!file.exists()) {
      file.mkdirs();
    }
    // 将imagePath存储到request对象中
    // request.setAttribute("imagePath", imagePath);
    // 将imagePath存储到application对象中
    application.setAttribute("imagePath", imagePath);
    // 获取目标文件在服务器主机中的绝对路径
    String realPath = application.getRealPath(imagePath);
    System.out.println("文件的绝对路径：" + realPath);
    // 从缓存中读取图片
    BufferedInputStream bis = new BufferedInputStream(new FileInputStream(this.some));
    // 构造指向目标文件的字节输出流对象，用来向目标文件写入数据
    BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(realPath));
    // 写入数据到目标文件中
    IOUtils.copy(bis, bos);
    bis.close();
    bos.close();
    return "success";
  }

  public String test() {
    String imageName = "file_1652507858364.JPG";
    imagePath = "upload-image/" + imageName;
    System.out.println("imagePath:" + imagePath);
    return "success";
  }

  public String test1() throws IOException {
    return execute();
  }

  public File getSome() {
    return some;
  }

  public void setSome(File some) {
    this.some = some;
  }

  public String getSomeFileName() {
    return someFileName;
  }

  public void setSomeFileName(String someFileName) {
    this.someFileName = someFileName;
  }

  public String getSomeContentType() {
    return someContentType;
  }

  public void setSomeContentType(String someContentType) {
    this.someContentType = someContentType;
  }

  public String getImagePath() {
    return imagePath;
  }

  public void setImagePath(String imagePath) {
    this.imagePath = imagePath;
  }
}

uploadform.jsp 的代码如下：

    文件上传



    文件上传


    
    

uploadimage.jsp 的代码如下：

    Title



    文件上传成功