SpringMVC (JSR303 & 拦截器)

目录

一、JSR303 

1、什么是JSR303

 2、导入pom依赖

3、后端代码

4、前端

二、拦截器

---

一、JSR303 

1、什么是JSR303

JSR303就是服务端验证

 2、导入pom依赖

      org.hibernate
      hibernate-validator
      6.0.7.Final
    

3、后端代码

Clazz

 都是判空

 @NotNull 作用基本数据类型
 @NotEmpty 作用集合数组
 @NotBlank 作用字符串

package com.zsx.ssm.model;


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

/**
 * @NotNull 作用基本数据类型
 * @NotEmpty 作用集合数组
 * @NotBlank 作用字符串
 */


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;
    }
}

ClazzController

package com.zsx.ssm.controller;

import com.zsx.ssm.biz.ClazzBiz;
import com.zsx.ssm.model.Clazz;
import com.zsx.ssm.model.dto.ClazzDto;
import com.zsx.ssm.util.PageBean;
import org.apache.commons.io.FileUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.*;
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.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author zsx
 * @site 155954····
 * @company 交换余生
 * @create 2022--08--17  19:07
 */
@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
    @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();
        //传了id代表修改，没传代表增加
        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();
            //违背了规则
            List fieldErrors = bindingResult.getFieldErrors();
            for (FieldError fieldError : fieldErrors) {
                //cid/cname/cteacher:不为空
//                System.out.println(fieldError.getField() + ":" + fieldError.getDefaultMessage());
                msg.put(fieldError.getField(),fieldError.getDefaultMessage());
            }
            request.setAttribute("msg",msg);
            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
     * @param clazzDto
     * @return
     */
    @RequestMapping("/upload")
    public String upload(ClazzDto clazzDto){
        try {
            //前台上传的文件
            MultipartFile picFile = clazzDto.getPicFile();
//            InputStream inputStream = picFile.getInputStream();
            //实际应该配置到 resource.properties 中
            String disPath="E:/temp";//图片存放地址
            //数据库保存的地址   也是访问地址
            String requestPath="/upload/mvc/";
//            拿到上传文件的名字
            String filename = picFile.getOriginalFilename();
            FileUtils.copyInputStreamToFile(picFile.getInputStream(),new File(disPath+filename));
            Clazz clazz = new Clazz();
            clazz.setCid(clazzDto.getCid());
            clazz.setPic(requestPath+filename);
            this.clazzBiz.updateByPrimaryKeySelective(clazz);

//            FileOutputStream fileOutputStream = new FileOutputStream(new File("e/temp/1.png"));
//            byte[] bbuf = new byte[1024];
//            int i=0;
//            while (true){
//                i=inputStream.read(bbuf,0,i);
//                fileOutputStream.write(bbuf,0,i);
//                if(i<0){
//                    break;
//                }
//            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return "redirect:/clz/list";
    }


    /**
     * 文件下载
     * @param clazzDto
     * @return
     */
    @RequestMapping("/dowload")
    public ResponseEntity dowload(ClazzDto clazzDto){
        try {
            Clazz clazz = this.clazzBiz.selectByPrimaryKey(clazzDto.getCid());
            String pic = clazz.getPic();
            String disPath="E:/temp";//图片存放地址
            //数据库保存的地址   也是访问地址
            String requestPath="/upload/mvc/";
            String realPath = pic.replace(requestPath,disPath);
            String fileName = realPath.substring(realPath.lastIndexOf("/")+1);
            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;
    }

}

OneHandlerInterceptor

package com.zsx.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 zsx
 * @site 155954····
 * @company 交换余生
 * @create 2022--08--19  19:29
 */
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 {
        //完成后处理
        System.out.println("[OneHandlerInterceptor] . afterCompletion...");
    }
}

4、前端

clzEdit.jsp

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



    
    


<%--form action="${pageContext.request.contextPath }/clz/${empty b ? 'add' : 'edit'}" method="post">--%>

    cid:${msg.cid}

    cname:${msg.cname}

    cteacher:${msg.cteacher}

    

效果图：

二、拦截器

1、后台

LoginController

package com.zsx.ssm.controller;

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

import javax.servlet.http.HttpServletRequest;

/**
 * @author zsx
 * @site 155954····
 * @company 交换余生
 * @create 2022--08--19  19:57
 */
@Controller
public class LoginController {
    /**
     * 登录
     * @param request
     * @return
     */
    @RequestMapping("/login")
    public String login(HttpServletRequest request){
        //登录成功保留用户信息
        String uname = request.getParameter("uname");
        if("zsx".equals(uname)){
            request.getSession().setAttribute("uname",uname);
        }
        return "index";
    }

    /**
     * 退出
     * @param request
     * @return
     */
    @RequestMapping("/logout")
    public String logout(HttpServletRequest request){
        //消除Session
        request.getSession().invalidate();
        return "index";
    }
}

OneHandlerInterceptor

package com.zsx.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 zsx
 * @site 155954····
 * @company 交换余生
 * @create 2022--08--19  19:29
 */
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");
        //如果是login/logout  放行   不拦截  反之都拦截
        String url = request.getRequestURL().toString();
        if(url.indexOf("/login") > 0  || url.indexOf("/logout") > 0){
            return true;
        }
            //对于请求业务方法   只有登陆过，存在session数据  才能访问
            String uname = (String)request.getSession().getAttribute("uname");
            if(uname == null || "".equals(uname)){
                response.sendRedirect("/login.jsp");
                return false;
            }
        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 {
        //完成后处理
        System.out.println("[OneHandlerInterceptor] . afterCompletion...");
    }
}

springmvc-servlet.xml

效果图：

未登录被拦截时：

登录后：

登录后访问数据展示页面：

退出登录后：