通过拦截器创建一个登录小案例

一、定义拦截器

1.1、创建Java类继承自WebMvcConfigurerAdapter，并通过@Configruation注解进行标注

 

1.2、重写父类addInterceptors方法，创建HandlerInterceptor对象

这里案例是类似一个登录系统,账号是admin,密码是123

 

package demo.interceptor;

import demo.controller.TestController;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.PrintWriter;

@Configuration
public class MyInterceptor extends WebMvcConfigurerAdapter {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        HandlerInterceptor handlerInterceptor = new HandlerInterceptor() {
             /**
             * 拦截请求的方法
             */
            @Override
            public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
                request.setCharacterEncoding("utf-8");
                response.setCharacterEncoding("utf-8");
                response.setContentType("text/html;charset=utf-8");
                String name = request.getParameter("name");
                String passwd = request.getParameter("passwd");
                if (name.equals("admin")&&passwd.equals("123")){
                    return true;
                }else{
                    return false;
                }
                //true=放行；false=拦截（直接大白页）
            }
        };
        registry.addInterceptor(handlerInterceptor).addPathPatterns("/**");
    }
}

 

1.3、在addInterceptors方法中，将HandlerInterceptor对象放到InterceptorRegistry对象中，并通过addPathPatterns方法定义拦截规则

registry.addInterceptor(handlerInterceptor).addPathPatterns("/**"); //拦截一切请求

二、全部源代码

package demo.interceptor;

import demo.controller.TestController;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.PrintWriter;

@Configuration
public class MyInterceptor extends WebMvcConfigurerAdapter {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        HandlerInterceptor handlerInterceptor = new HandlerInterceptor() {
             /**
             * 拦截请求的方法
             */
            @Override
            public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
                request.setCharacterEncoding("utf-8");
                response.setCharacterEncoding("utf-8");
                response.setContentType("text/html;charset=utf-8");
                String name = request.getParameter("name");
                String passwd = request.getParameter("passwd");
                if (name.equals("admin")&&passwd.equals("123")){
                    return true;
                }else{
                    return false;
                }
                //true=放行；false=拦截（直接大白页）
            }
        };
        registry.addInterceptor(handlerInterceptor).addPathPatterns("/**");
    }
}