SpringMVC攔截器和數據校驗

時間 2019-11-12

原文原文鏈接

一、什麼是攔截器

　　Spring MVC中的攔截器（Interceptor）相似於Servlet中的過濾器（Filter），它主要用於攔截用戶請求並做相應的處理。例如經過攔截器能夠進行權限驗證、記錄請求信息的日誌、判斷用戶是否登陸等。在SpringMVC中經過實現HandlerInterceptor接口實現自定義攔截器類。html

二、攔截器案例

（1）MyIntercept

package com.springmvc.intercept;

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

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

public class MyIntercept implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("=========攔截器當中的handle方法=========");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("=======在HandlerAdapter以後執行，在DispatcherServlet解析視圖以前執行=====");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("=========呈現以後調用=========");
    }
}

代碼實現

（2）攔截器配置spring-mvc.xml

<!--利用default-servlet放行資源-->
<mvc:default-servlet-handler/>

<!--配置攔截器-->
<mvc:interceptors>
    <mvc:interceptor>
        <mvc:mapping path="/my/**"/>
        <bean class="com.springmvc.intercept.MyIntercept"></bean>
    </mvc:interceptor>
</mvc:interceptors>

代碼實現

（3）MyController

@Controller
@RequestMapping("/my")
public class MyController {
    @RequestMapping("/doFirst")
    public String doFirst(){
        System.out.println("=========控制器中的方法=========");
        return "index";
    }

代碼實現

（4）控制檯效果

三、Spring MVC的數據校驗

　3.1 數據校驗案例

（1）導入依賴

<!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-validator -->
<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-validator</artifactId>
  <version>5.4.1.Final</version>
</dependency>

代碼實現

（2）validate.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>測試案例</title>
</head>
<body>
    <form action="/my/validate" method="post">
        編號：<input type="text" name="uid"/><br/>
        姓名：<input type="text" name="uName"/><br/>
        郵箱：<input type="text" name="email"/><br/>
        電話：<input type="text" name="phone"/><br/>
        身份證號：<input type="text" name="userCode"/><br/>
        <input type="submit" value="提交"/>
    </form>
</body>
</html>

代碼實現

（3）實體類UserInfo

package com.springmvc.entity;


import org.hibernate.validator.constraints.Email;
import org.hibernate.validator.constraints.Length;

import javax.validation.constraints.NotNull;
import javax.validation.constraints.Pattern;

public class UserInfo {

    @NotNull(message="編號不能爲空")
    private Integer uid;

    @NotNull
    @Length(min = 2,max = 8,message = "用戶名不能少於2位或大於8位")
    private String uName;

    @Email(message = "郵箱格式不正確")
    private String email;

    @Pattern(regexp = "/^1[3456789]\\d{9}$/",message = "手機號式不正確")
    private String phone;

    @Pattern(regexp = "/(^\\d{15}$)|(^\\d{18}$)|(^\\d{17}(\\d|X|x)$)/",message = "身份證號格式不正確")
    private String userCode;

    public Integer getUid() {
        return uid;
    }

    public void setUid(Integer uid) {
        this.uid = uid;
    }

    public String getuName() {
        return uName;
    }

    public void setuName(String uName) {
        this.uName = uName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getUserCode() {
        return userCode;
    }

    public void setUserCode(String userCode) {
        this.userCode = userCode;
    }
}

代碼實現

（4）MyController

package com.springmvc.controller;

import com.springmvc.entity.UserInfo;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.validation.ObjectError;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.validation.Valid;
import java.util.List;

@Controller
@RequestMapping("/my")
public class MyController {
    @RequestMapping("/doFirst")
    public String doFirst(){
        System.out.println("=========控制器中的方法=========");
        return "index";
    }

    @RequestMapping("/validate")
    public String Validate(@Valid UserInfo info, BindingResult bindingResult){
        //若是有異常信息
        if (bindingResult.hasErrors()){
            //獲取異常信息對象
            List<ObjectError> allErrors = bindingResult.getAllErrors();
            //將異常信息輸出
            for (ObjectError errors:allErrors) {
                System.out.println(errors.getDefaultMessage());
            }
        }
        return "index";
    }
}