文件上传与BeanUtils工具类应用整体Servlet 类代码举例
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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