JSR303和拦截器

目录

一、JSR303

1、pom依赖

2、后端

①实体类

②ClazzController.java

3、前端

二、拦截器

1、拦截器的初步认识

①OneHandlerInterceptor

②HelloController

③springmvc-servlet的配置

2、拦截器链

 ①TwoHandlerInterceptor

 ②springmvc-servlet的配置

3、登录权限控制

3.1 前端

3.2 后端

---

一、JSR303

1、pom依赖

      org.hibernate
      hibernate-validator
      6.0.7.Final
    

2、后端

①实体类

package com.chenchen.ssm.model;

import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.NotNull;

/**
 * NotNull:针对的是基本数据类型
 * NotEmpty:作用于集合
 * NotBlank:作用于字符串
 */
public class Clazz {
    @NotNull(message = "cid不能为空")
    protected Integer cid;

    @NotBlank(message = "班级名称不能为空")
    protected String cname;

    @NotBlank(message = "教员老师不能为空")
    protected String cteacher;

    protected String pic;

    public Clazz(Integer cid, String cname, String cteacher, String pic) {
        this.cid = cid;
        this.cname = cname;
        this.cteacher = cteacher;
        this.pic = pic;
    }

    public Clazz() {
        super();
    }

    public Integer getCid() {
        return cid;
    }

    public void setCid(Integer cid) {
        this.cid = cid;
    }

    public String getCname() {
        return cname;
    }

    public void setCname(String cname) {
        this.cname = cname;
    }

    public String getCteacher() {
        return cteacher;
    }

    public void setCteacher(String cteacher) {
        this.cteacher = cteacher;
    }

    public String getPic() {
        return pic;
    }

    public void setPic(String pic) {
        this.pic = pic;
    }
}

②ClazzController.java

package com.chenchen.ssm.web;

import com.chenchen.ssm.biz.ClazzBiz;
import com.chenchen.ssm.model.Clazz;
import com.chenchen.ssm.model.dto.ClazzDto;
import com.chenchen.ssm.util.PageBean;
import org.apache.commons.io.FileUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import javax.validation.Valid;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Controller
@RequestMapping("/clz")
public class ClazzController {
    @Autowired
    private ClazzBiz clazzBiz;
//    list->clzlist
//    toList->重定向list->"redirect:/clz/list"
//    toEdit->跳转到编辑界面->clzEdit
//    Clazz:以前是通过模型驱动接口封装，现在是直接在方法中接收参数即可

    @RequestMapping("/list")
    public String list(Clazz clazz, HttpServletRequest request){
        PageBean pageBean=new PageBean();
        pageBean.setRequest(request);
        List lst = this.clazzBiz.listPager(clazz, pageBean);
        request.setAttribute("lst",lst);
        request.setAttribute("pageBean",pageBean);
        return "clzList";
    }

    @RequestMapping("/toEdit")
    public String toEdit(Clazz clazz, HttpServletRequest request){
        Integer cid = clazz.getCid();
//        传递的id代表了修改，没传代表新增
        if(cid != null){
            List lst = this.clazzBiz.listPager(clazz, null);
            request.setAttribute("b",lst.get(0));
        }
        return "clzEdit";
    }

    @RequestMapping("/add")
    public String add(Clazz clazz){
        this.clazzBiz.insertSelective(clazz);
        return "redirect:/clz/list";
    }

    /**
     * @Valid 是与实体类中的服务端校验 注解配合使用的
     * BindingResult存放了所有违背校验的错误信息
     * @param clazz
     * @param bindingResult
     * @return
     */
    @RequestMapping("/valiAdd")
    public String valiAdd(@Valid Clazz clazz, BindingResult bindingResult,HttpServletRequest request){
        if(bindingResult.hasErrors()){
            Map msg=new HashMap();
//            违背规则
            List fieldErrors = bindingResult.getFieldErrors();
            for (FieldError fieldError : fieldErrors) {
//                cid : cid不能为空
                System.out.println(fieldError.getField() + ":" + fieldError.getDefaultMessage());
//                msg.put(cid,cid不能为空)
                msg.put(fieldError.getField(),fieldError.getDefaultMessage());

            }
            request.setAttribute("msg",msg);
//            如果出现了错误，一个将提示语显示在表单提交元素后方
            return "clzEdit";
        }else{
            this.clazzBiz.insertSelective(clazz);
        }
        return "redirect:/clz/list";
    }

    @RequestMapping("/edit")
    public String edit(Clazz clazz){
        this.clazzBiz.updateByPrimaryKeySelective(clazz);
        return "redirect:/clz/list";
    }

    @RequestMapping("/del")
    public String del(Clazz clazz){
        this.clazzBiz.deleteByPrimaryKey(clazz.getCid());
        return "redirect:/clz/list";
    }

//    文件上传
    @RequestMapping("/upload")
    public String upload(ClazzDto clazzDto){
        try{
//          前台上传的文件
            MultipartFile picFile = clazzDto.getPicFile();
//            InputStream inputStream = picFile.getInputStream();
            /*FileOutputStream fout = new FileOutputStream(new File("D/temp/1.png"));
            byte[] bbuf=new byte[1024];
            int len = 0;
            while(true){
                len=inputStream.read(bbuf,0,len);
                fout.write(bbuf,0,len);
                if(len<0){
                    break;
                }
            }*/
//            实际应该配置到resource.properties中
            String dispath="E:/temp/images";//图片的存放地址
//            http://localhost:8080/upload/mvc/**.png
            String requestPath="/upload/mvc";//数据库保存的地址，也是访问地址
//            拿到上传文件的名字
            String fileName = picFile.getOriginalFilename();//**.png

            FileUtils.copyInputStreamToFile(picFile.getInputStream(),new File(dispath+fileName));
//           将图片上传之后，并且将图片地址更新到数据库中
            Clazz clazz=new Clazz();
            clazz.setCid(clazzDto.getCid());
            clazz.setPic(requestPath+fileName);
            this.clazzBiz.updateByPrimaryKeySelective(clazz);
        }catch (Exception e){
            e.printStackTrace();
        }
        return "redirect:/clz/list";
    }

    //    文件下载
    @RequestMapping("/download")
    public ResponseEntity download(ClazzDto clazzDto){
        try{
//            1.点击下载传递文件的ID，通过文件的ID查询出文件的路径
            Clazz clazz = this.clazzBiz.selectByPrimaryKey(clazzDto.getCid());
            String pic=clazz.getPic();// /upload/mvc/**.png
//              实际应该配置到resource.properties中
            String diskPath="E:/temp/images/";//图片的存放地址
//            http://localhost:8080/upload/mvc/图片.png
            String requestPath="/upload/mvc/";//数据库保存的地址，也是访问地址
            
//            2.通过文件的请求地址，转换成文件存放的硬盘地
            String realPath=pic.replace(requestPath,diskPath);// E:/temp/images
            String fileName=realPath.substring(realPath.lastIndexOf("/")+1);
//            3.将硬盘中文件下载下来->固定代码
            File file=new File(realPath);
            HttpHeaders headers = new HttpHeaders();//http头信息
            String downloadFileName = new String(fileName.getBytes("UTF-8"),"iso-8859-1");//设置编码
            headers.setContentDispositionFormData("attachment", downloadFileName);
            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
            //MediaType:互联网媒介类型  contentType：具体请求中的媒体类型信息
            return new ResponseEntity(FileUtils.readFileToByteArray(file),headers, HttpStatus.OK);
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }
}

3、前端

clzEdit.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>



    
    


<%--

--%>

    cid:${msg.cid}

    cname:${msg.cname}

    cteacher:${msg.cteacher}

    

运行效果：

输入为空则提示

二、拦截器

1、拦截器的初步认识

①OneHandlerInterceptor

package com.chenchen.ssm.intercept;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @author chenchen
 * @create 2022-08-19 18:32
 */
public class OneHandlerInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
//        预处理
        System.out.println("[OneHandlerInterceptor] . preHandle");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
//       后处理
        System.out.println("[OneHandlerInterceptor] . postHandle...");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
//        完成后执行
        System.out.println("[OneHandlerInterceptor] . afterCompletion...");
    }
}

②HelloController

package com.chenchen.ssm.web;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * @author chenchen
 * @create 2022-08-19 19:21
 */
@Controller
public class HelloController {

    @RequestMapping("hello")
    public String hello(){
        System.out.println("进入业务方法...");
        return "index";
    }
}

③springmvc-servlet的配置

2、拦截器链

 ①TwoHandlerInterceptor

package com.chenchen.ssm.intercept;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @author chenchen
 * @create 2022-08-19 18:32
 */
public class TwoHandlerInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
//        预处理
        System.out.println("[TwoHandlerInterceptor] . preHandle");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
//       后处理
        System.out.println("[TwoHandlerInterceptor] . postHandle...");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
//        完成后执行
        System.out.println("[TwoHandlerInterceptor] . afterCompletion...");
    }
}

 ②springmvc-servlet的配置

运行效果：

3、登录权限控制

3.1 前端

login.jsp

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2022/8/19
  Time: 19:55
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>


    


登录界面

3.2 后端

LoginController

package com.chenchen.ssm.web;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;

/**
 * @author chenchen
 * @create 2022-08-19 19:52
 */
@Controller
public class LoginController {

    @RequestMapping("/login")
    public String login(HttpServletRequest request){
//        登录成功需要保存用户信息
        String uname = request.getParameter("uname");
        if("zhangsan".equals(uname)){
            request.getSession().setAttribute("uname",uname);
        }
        return "index";
    }

    @RequestMapping("/loginout")
    public String loginout(HttpServletRequest request){
        request.getSession().invalidate();
        return "index";
    }

}

运行效果：