SpringMVC框架自定义拦截器的过程详解

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@RequestMapping("/dept")
@Controller
public class DeptController {
    /**
     * 测试方法
     * @return
     */
    @RequestMapping("/findAll.do")
    public String findALL(){
        System.out.println("测试拦截器，执行了……");
        return "suc";
    }
}

<!--配置拦截器们-->
<mvc:interceptors>
    <!--配置拦截器1-->
    <mvc:interceptor>
        <!--拦截哪些资源-->
        <mvc:mapping path="/dept/**"/>
        <!--不拦截哪些资源-->
        <!--<mvc:exclude-mapping path=""/>-->
        <!--拦截器对象-->
        <bean class="com.qcby.demo4.MyInterceptor"></bean>
    </mvc:interceptor>
</mvc:interceptors>

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 * 拦截器类
 */
public class MyInterceptor implements HandlerInterceptor {
    /**
     * 拦截器之前：拦截controller中的findAll方法，放行，执行controller中的方法
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("MyInterceptor中的拦截器preHandle方法执行了……");
        // return false - 拦截，不放行；return true - 拦截，放行
        return true;
    }
    /**
     * 拦截器之后：controller方法执行后，要拦截的方法
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("MyInterceptor中的postHandle方法执行了……");
        // 可以进行页面跳转
        request.getRequestDispatcher("/pages/suc.jsp").forward(request,response);
        return;
    }
    /**
     * controller跳转的jsp页面都执行完成了，最后执行该方法
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @throws Exception
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("MyInterceptor中的afterComplrtion方法执行了……");
    }
}

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 * 拦截器类
 * 配置多个拦截器
 */
public class MyInterceptor2 implements HandlerInterceptor {
    /**
     * 拦截controller中的方法，但放行
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("MyInterceptor2的拦截器preHandle方法执行了……");
        // 放行
        return true;
    }
    /**
     * controller方法执行后，要拦截的方法
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("MyInterceptor2的postHandle方法执行了……");
    }
    /**
     * controller跳转的jsp页面都执行完成了，最后执行该方法
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @throws Exception
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("MyInterceptor2的afterComplrtion方法执行了……");
    }
}

<!--配置拦截器们-->
<mvc:interceptors>
    <!--配置拦截器1-->
    <mvc:interceptor>
        <!--拦截哪些资源-->
        <mvc:mapping path="/dept/**"/>
        <!--不拦截哪些资源-->
        <!--<mvc:exclude-mapping path=""/>-->
        <!--拦截器对象-->
        <bean class="com.qcby.demo4.MyInterceptor"></bean>
    </mvc:interceptor>
    <!--配置拦截器2-->
    <mvc:interceptor>
        <!--拦截哪些资源-->
        <mvc:mapping path="/**"/>
        <!--拦截器对象-->
        <bean class="com.qcby.demo4.MyInterceptor2"></bean>
    </mvc:interceptor>
</mvc:interceptors>