• 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

    1. <dependency>
    2.       <groupId>org.hibernategroupId>
    3.       <artifactId>hibernate-validatorartifactId>
    4.       <version>6.0.7.Finalversion>
    5.     dependency>

    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

    1. package com.zsx.ssm.model;
    2.  
    3.  
    4. import javax.validation.constraints.NotBlank;
    5. import javax.validation.constraints.NotEmpty;
    6. import javax.validation.constraints.NotNull;
    7.  
    8. /**
    9.  * @NotNull 作用基本数据类型
    10.  * @NotEmpty 作用集合数组
    11.  * @NotBlank 作用字符串
    12.  */
    13.  
    14.  
    15. public class Clazz {
    16.     @NotNull(message = "cid不能为空")
    17.     protected Integer cid;
    18.     @NotBlank(message = "班级名称不能为空")
    19.     protected String cname;
    20.     @NotBlank(message = "教员不能为空")
    21.     protected String cteacher;
    22.  
    23.     protected String pic;
    24.  
    25.     public Clazz(Integer cid, String cname, String cteacher, String pic) {
    26.         this.cid = cid;
    27.         this.cname = cname;
    28.         this.cteacher = cteacher;
    29.         this.pic = pic;
    30.     }
    31.  
    32.     public Clazz() {
    33.         super();
    34.     }
    35.  
    36.     public Integer getCid() {
    37.         return cid;
    38.     }
    39.  
    40.     public void setCid(Integer cid) {
    41.         this.cid = cid;
    42.     }
    43.  
    44.     public String getCname() {
    45.         return cname;
    46.     }
    47.  
    48.     public void setCname(String cname) {
    49.         this.cname = cname;
    50.     }
    51.  
    52.     public String getCteacher() {
    53.         return cteacher;
    54.     }
    55.  
    56.     public void setCteacher(String cteacher) {
    57.         this.cteacher = cteacher;
    58.     }
    59.  
    60.     public String getPic() {
    61.         return pic;
    62.     }
    63.  
    64.     public void setPic(String pic) {
    65.         this.pic = pic;
    66.     }
    67. }
    ClazzController
    1. package com.zsx.ssm.controller;
    2.  
    3. import com.zsx.ssm.biz.ClazzBiz;
    4. import com.zsx.ssm.model.Clazz;
    5. import com.zsx.ssm.model.dto.ClazzDto;
    6. import com.zsx.ssm.util.PageBean;
    7. import org.apache.commons.io.FileUtils;
    8. import org.springframework.beans.factory.annotation.Autowired;
    9. import org.springframework.http.*;
    10. import org.springframework.stereotype.Controller;
    11. import org.springframework.validation.BindingResult;
    12. import org.springframework.validation.FieldError;
    13. import org.springframework.web.bind.annotation.RequestMapping;
    14. import org.springframework.web.multipart.MultipartFile;
    15.  
    16. import javax.servlet.http.HttpServletRequest;
    17. import javax.validation.Valid;
    18. import java.io.File;
    19. import java.util.HashMap;
    20. import java.util.List;
    21. import java.util.Map;
    22.  
    23. /**
    24.  * @author zsx
    25.  * @site 155954····
    26.  * @company 交换余生
    27.  * @create 2022--08--17  19:07
    28.  */
    29. @Controller
    30. @RequestMapping("/clz")
    31. public class ClazzController {
    32.     @Autowired
    33.     private ClazzBiz clazzBiz;
    34.  
    35. //    list-->clzList
    36. //    toList-->重定向list-->redirect:/clz/list
    37. //    toEdit-->跳转到编辑界面-->clzEdit
    38. //    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
    39.     @RequestMapping("/list")
    40.     public String list(Clazz clazz, HttpServletRequest request){
    41.         PageBean pageBean=new PageBean();
    42.         pageBean.setRequest(request);
    43.         List lst = this.clazzBiz.listPager(clazz, pageBean);
    44.         request.setAttribute("lst",lst);
    45.         request.setAttribute("pageBean",pageBean);
    46.         return "clzList";
    47.     }
    48.     @RequestMapping("/toEdit")
    49.     public String toEdit(Clazz clazz, HttpServletRequest request){
    50.         Integer cid = clazz.getCid();
    51.         //传了id代表修改，没传代表增加
    52.         if(cid != null){
    53.             List lst = this.clazzBiz.listPager(clazz, null);
    54.             request.setAttribute("b",lst.get(0));
    55.         }
    56.         return "clzEdit";
    57.     }
    58.     @RequestMapping("/add")
    59.     public String add(Clazz clazz){
    60.         this.clazzBiz.insertSelective(clazz);
    61.         return "redirect:/clz/list";
    62.     }
    63.  
    64.     /**
    65.      * @Valid 是与实体类中的服务端校验  注解配合使用的
    66.      * BindingResult  存放了所有违背  校验的信息
    67.      * @param clazz
    68.      * @param bindingResult
    69.      * @return
    70.      */
    71.     @RequestMapping("/valiAdd")
    72.     public String valiAdd(@Valid Clazz clazz, BindingResult bindingResult,HttpServletRequest request){
    73.         if(bindingResult.hasErrors()){
    74.             Map msg = new HashMap();
    75.             //违背了规则
    76.             List fieldErrors = bindingResult.getFieldErrors();
    77.             for (FieldError fieldError : fieldErrors) {
    78.                 //cid/cname/cteacher:不为空
    79. //                System.out.println(fieldError.getField() + ":" + fieldError.getDefaultMessage());
    80.                 msg.put(fieldError.getField(),fieldError.getDefaultMessage());
    81.             }
    82.             request.setAttribute("msg",msg);
    83.             return "clzEdit";
    84.         }else{
    85.             this.clazzBiz.insertSelective(clazz);
    86.         }
    87.         return "redirect:/clz/list";
    88.     }
    89.  
    90.     @RequestMapping("/edit")
    91.     public String edit(Clazz clazz){
    92.         this.clazzBiz.updateByPrimaryKeySelective(clazz);
    93.         return "redirect:/clz/list";
    94.     }
    95.     @RequestMapping("/del")
    96.     public String del(Clazz clazz){
    97.         this.clazzBiz.deleteByPrimaryKey(clazz.getCid());
    98.         return "redirect:/clz/list";
    99.     }
    100.  
    101.     /**
    102.      * 文件上传
    103.      * @param clazzDto
    104.      * @return
    105.      */
    106.     @RequestMapping("/upload")
    107.     public String upload(ClazzDto clazzDto){
    108.         try {
    109.             //前台上传的文件
    110.             MultipartFile picFile = clazzDto.getPicFile();
    111. //            InputStream inputStream = picFile.getInputStream();
    112.             //实际应该配置到 resource.properties 中
    113.             String disPath="E:/temp";//图片存放地址
    114.             //数据库保存的地址   也是访问地址
    115.             String requestPath="/upload/mvc/";
    116. //            拿到上传文件的名字
    117.             String filename = picFile.getOriginalFilename();
    118.             FileUtils.copyInputStreamToFile(picFile.getInputStream(),new File(disPath+filename));
    119.             Clazz clazz = new Clazz();
    120.             clazz.setCid(clazzDto.getCid());
    121.             clazz.setPic(requestPath+filename);
    122.             this.clazzBiz.updateByPrimaryKeySelective(clazz);
    123.  
    124. //            FileOutputStream fileOutputStream = new FileOutputStream(new File("e/temp/1.png"));
    125. //            byte[] bbuf = new byte[1024];
    126. //            int i=0;
    127. //            while (true){
    128. //                i=inputStream.read(bbuf,0,i);
    129. //                fileOutputStream.write(bbuf,0,i);
    130. //                if(i<0){
    131. //                    break;
    132. //                }
    133. //            }
    134.         } catch (Exception e) {
    135.             e.printStackTrace();
    136.         }
    137.  
    138.         return "redirect:/clz/list";
    139.     }
    140.  
    141.  
    142.     /**
    143.      * 文件下载
    144.      * @param clazzDto
    145.      * @return
    146.      */
    147.     @RequestMapping("/dowload")
    148.     public ResponseEntity dowload(ClazzDto clazzDto){
    149.         try {
    150.             Clazz clazz = this.clazzBiz.selectByPrimaryKey(clazzDto.getCid());
    151.             String pic = clazz.getPic();
    152.             String disPath="E:/temp";//图片存放地址
    153.             //数据库保存的地址   也是访问地址
    154.             String requestPath="/upload/mvc/";
    155.             String realPath = pic.replace(requestPath,disPath);
    156.             String fileName = realPath.substring(realPath.lastIndexOf("/")+1);
    157.             File file=new File(realPath);
    158.             HttpHeaders headers = new HttpHeaders();//http头信息
    159.             String downloadFileName = new String(fileName.getBytes("UTF-8"),"iso-8859-1");//设置编码
    160.             headers.setContentDispositionFormData("attachment", downloadFileName);
    161.             headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
    162.             //MediaType:互联网媒介类型  contentType：具体请求中的媒体类型信息
    163.             return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),headers, HttpStatus.OK);
    164.         } catch (Exception e) {
    165.             e.printStackTrace();
    166.         }
    167.         return null;
    168.     }
    169.  
    170. }
    OneHandlerInterceptor
    1. package com.zsx.ssm.intercept;
    2.  
    3. import org.springframework.web.servlet.HandlerInterceptor;
    4. import org.springframework.web.servlet.ModelAndView;
    5.  
    6. import javax.servlet.http.HttpServletRequest;
    7. import javax.servlet.http.HttpServletResponse;
    8.  
    9. /**
    10.  * @author zsx
    11.  * @site 155954····
    12.  * @company 交换余生
    13.  * @create 2022--08--19  19:29
    14.  */
    15. public class OneHandlerInterceptor implements HandlerInterceptor {
    16.  
    17.     @Override
    18.     public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    19.         //预处理
    20.         System.out.println("[OneHandlerInterceptor] . preHandle");
    21.         return true;
    22.     }
    23.  
    24.     @Override
    25.     public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    26.         //后处理
    27.         System.out.println("[OneHandlerInterceptor] . postHandle...");
    28.     }
    29.  
    30.     @Override
    31.     public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    32.         //完成后处理
    33.         System.out.println("[OneHandlerInterceptor] . afterCompletion...");
    34.     }
    35. }

    4、前端

    clzEdit.jsp

    1. <%@ page language="java" contentType="text/html; charset=UTF-8"
    2.          pageEncoding="UTF-8"%>
    3. html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    4. <html>
    5. <head>
    6.     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    7.     <title>博客的编辑界面title>
    8. head>
    9. <body>
    10. <%--form action="${pageContext.request.contextPath }/clz/${empty b ? 'add' : 'edit'}" method="post">--%>
    11. <form action="${pageContext.request.contextPath }/clz/${empty b ? 'valiAdd' : 'edit'}" method="post">
    12.     cid:<input type="text" name="cid" value="${b.cid }"><span style="color: red;">${msg.cid}span><br>
    13.     cname:<input type="text" name="cname" value="${b.cname }"><span style="color: red;">${msg.cname}span><br>
    14.     cteacher:<input type="text" name="cteacher" value="${b.cteacher }"><span style="color: red;">${msg.cteacher}span><br>
    15.     <input type="submit">
    16. form>
    17. body>
    18. html>

    效果图：

    二、拦截器

    1、后台

    LoginController
    1. package com.zsx.ssm.controller;
    2.  
    3. import org.springframework.stereotype.Controller;
    4. import org.springframework.web.bind.annotation.RequestMapping;
    5.  
    6. import javax.servlet.http.HttpServletRequest;
    7.  
    8. /**
    9.  * @author zsx
    10.  * @site 155954····
    11.  * @company 交换余生
    12.  * @create 2022--08--19  19:57
    13.  */
    14. @Controller
    15. public class LoginController {
    16.     /**
    17.      * 登录
    18.      * @param request
    19.      * @return
    20.      */
    21.     @RequestMapping("/login")
    22.     public String login(HttpServletRequest request){
    23.         //登录成功保留用户信息
    24.         String uname = request.getParameter("uname");
    25.         if("zsx".equals(uname)){
    26.             request.getSession().setAttribute("uname",uname);
    27.         }
    28.         return "index";
    29.     }
    30.  
    31.     /**
    32.      * 退出
    33.      * @param request
    34.      * @return
    35.      */
    36.     @RequestMapping("/logout")
    37.     public String logout(HttpServletRequest request){
    38.         //消除Session
    39.         request.getSession().invalidate();
    40.         return "index";
    41.     }
    42. }
    43.  
    OneHandlerInterceptor
    1. package com.zsx.ssm.intercept;
    2.  
    3. import org.springframework.web.servlet.HandlerInterceptor;
    4. import org.springframework.web.servlet.ModelAndView;
    5.  
    6. import javax.servlet.http.HttpServletRequest;
    7. import javax.servlet.http.HttpServletResponse;
    8.  
    9. /**
    10.  * @author zsx
    11.  * @site 155954····
    12.  * @company 交换余生
    13.  * @create 2022--08--19  19:29
    14.  */
    15. public class OneHandlerInterceptor implements HandlerInterceptor {
    16.  
    17.     @Override
    18.     public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    19.         //预处理
    20.         System.out.println("[OneHandlerInterceptor] . preHandle");
    21.         //如果是login/logout  放行   不拦截  反之都拦截
    22.         String url = request.getRequestURL().toString();
    23.         if(url.indexOf("/login") > 0  || url.indexOf("/logout") > 0){
    24.             return true;
    25.         }
    26.             //对于请求业务方法   只有登陆过，存在session数据  才能访问
    27.             String uname = (String)request.getSession().getAttribute("uname");
    28.             if(uname == null || "".equals(uname)){
    29.                 response.sendRedirect("/login.jsp");
    30.                 return false;
    31.             }
    32.         return true;
    33.     }
    34.  
    35.     @Override
    36.     public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    37.         //后处理
    38.         System.out.println("[OneHandlerInterceptor] . postHandle...");
    39.     }
    40.  
    41.     @Override
    42.     public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    43.         //完成后处理
    44.         System.out.println("[OneHandlerInterceptor] . afterCompletion...");
    45.     }
    46. }

    springmvc-servlet.xml

    1. <mvc:interceptors>
    2.         
    3.         <mvc:interceptor>
    4.             <mvc:mapping path="/**"/>
    5.             <bean class="com.zsx.ssm.intercept.OneHandlerInterceptor">bean>
    6.         mvc:interceptor>
    7.         
    12.     mvc:interceptors>

    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：

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  • 原文地址：https://blog.csdn.net/weixin_61523879/article/details/126431523