文件上传与BeanUtils工具类应用整体代码举例

文件上传与BeanUtils工具类应用整体Servlet 类代码举例

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 1.为保存图片URL优化创建常量类

package com.lagou.base;

public final class Constants {

    //本地访问地址
    public static final String LOCAL_URL = "http://localhost:8080";

}

2. Servlet 类代码展示

package com.lagou.web.servlet;

import com.lagou.base.Constants;
import com.lagou.pojo.Course;
import com.lagou.service.CourseService;
import com.lagou.service.impl.CourseServiceImpl;
import com.lagou.utils.DateUtils;
import com.lagou.utils.UUIDUtils;
import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.IOUtils;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@WebServlet("/courseSalesInfo")
public class CourseSalesInfoServlet  extends HttpServlet {

    /**
     * 保存课程营销信息
     *      收集表单数据,封装到course对象中,将图片上传到tomcat服务器中
     * */
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        try {
            //1.创建Course对象
            Course course = new Course();

            //2.创建Map集合,用来收集数据
            Map<String,Object> map = new HashMap<>();

            //3.创建磁盘工厂对象
            DiskFileItemFactory factory = new DiskFileItemFactory();

            //4.文件上传核心对象
            ServletFileUpload fileUpload = new ServletFileUpload(factory);

            //5.解析request对象,获取表单项集合
            List<FileItem> list = fileUpload.parseRequest(req);

            //6.遍历集合 判断哪些是普通的表单项,那些是文件表单项
            for (FileItem item : list) {

                boolean formField = item.isFormField();
                if(formField){
                    //是普通表单项,获取表单项中的数据,保存到map
                    String fieldName = item.getFieldName();
                    String value = item.getString("UTF-8");
                    System.out.println(fieldName +" " + value);
                    //使用map收集数据
                    map.put(fieldName,value);
                }else{
                    //文件上传项
                    //获取文件名
                    String fileName = item.getName();
                    String newFileName = UUIDUtils.getUUID()+"_"+fileName;

                    //获取输入流
                    InputStream in = item.getInputStream();

                    //获取webapps的目录路径
                    String realPath = this.getServletContext().getRealPath("/");
                    String wabappsPath = realPath.substring(0, realPath.indexOf("lagou_edu_home"));

                    //创建输出流
                    OutputStream out = new FileOutputStream(wabappsPath+"/upload/" + newFileName);

                    IOUtils.copy(in,out);
                    out.close();
                    in.close();

                    //将图片路径进行保存
                    map.put("course_img_url", Constants.LOCAL_URL+"/upload/" + newFileName);
                }
            }

            //使用BeanUtils 将map中的数据封装到course对象
            BeanUtils.populate(course,map);

            String dateFormart = DateUtils.getDateFormart();
            CourseService cs = new CourseServiceImpl();

            if(map.get("id") != null){
                //修改操作
                //补全信息
                course.setUpdate_time(dateFormart);//修改时间
                String result = cs.updateCourseSalesInfo(course);
                //响应结果
                resp.getWriter().print(result);

            }else{
                //新建操作
                //补全信息
                course.setCreate_time(dateFormart);//创建时间
                course.setUpdate_time(dateFormart);//修改时间
                course.setStatus(1); //上架
                String result = cs.saveCourseSalesInfo(course);
                //响应结果
                resp.getWriter().print(result);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

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