SpringMVC-Interceptor

<!-- 配置 SpringMVC 的 DispatcherServlet -->
    <!-- The front controller of this Spring Web application, responsible for handling all application requests -->
    <servlet>
        <servlet-name>springDispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <!-- Map all requests to the DispatcherServlet for handling -->
    <servlet-mapping>
        <servlet-name>springDispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!-- 配置 HiddenHttpMethodFilter: 把 POST 请求转为 DELETE、PUT 请求 -->
    <filter>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

package top.finen.springmvc.interceptors;

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

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

public class FirstInterceptor implements HandlerInterceptor {

    /**
     * 该方法在目标方法之前被调用
     * 若返回值为true，则继续调用后续的拦截器和目标方法
     * 若返回值是false，则不会继续调用后续的拦截器和目标方法
     *
     * 可以考虑做权限，日志，事物等
     * @param httpServletRequest
     * @param httpServletResponse
     * @param o
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
        System.out.println("[FirstInterceptor] preHandle");
        return true;
    }

    /**
     * 在调用目标方法之后，但渲染视图之前
     * 可以对清秋浴中的属性或视图做出修改
     * @param httpServletRequest
     * @param httpServletResponse
     * @param o
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
        System.out.println("[FirstInterceptor] postHandle");
    }

    /**
     * 在渲染视图之后被调用。释放资源的
     * @param httpServletRequest
     * @param httpServletResponse
     * @param o
     * @param e
     * @throws Exception
     */
    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
        System.out.println("[FirstInterceptor] afterCompletion");
    }
}

	<mvc:interceptors>
		<!-- 配置自定义的拦截器 -->
		<bean class="top.finen.springmvc.interceptors.FirstInterceptor"></bean>

		<!-- 配置拦截器(不)作用的路径 -->
		<mvc:interceptor>
			<mvc:mapping path="/emps"/>
			<bean class="top.finen.springmvc.interceptors.SecondInterceptor"></bean>
		</mvc:interceptor>

		<!-- 配置 LocaleChanceInterceptor -->
		<bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor"</bean>
	</mvc:interceptors>

 	/**
     * 1.在@ExceptionHandler方法的入参中可以加入Exception类型的参数，该参数即对应发生的异常对象
     * 2.在@ExceptionHandler方法的入参中不能传入Map，若希望把异常信息传到页面上，需要使用ModelAndView作为返回值
     * 3.@ExceptionHandler方法标记的异常有优先级的问题
     * 4.@ControllerAdvice：如果在当前handler中招不到@ExceptionHandler方法方法来处理当前方法出现的异常。
     * 则将去@ControllerAdvice标记的类周宁查找@ExceptionHandler标记方法来处理异常。
     * @param e
     * @return
     */
    @ExceptionHandler({ArithmeticException.class})
    public ModelAndView handleArithmeticException(Exception e) {
        System.out.println("出异常了：" + e);
        ModelAndView mv = new ModelAndView(("error"));
        mv.addObject("exception", e);
        return mv;
    }

    @ExceptionHandler({RuntimeException.class})
    public ModelAndView handleArithmeticException2(Exception e) {
        System.out.println("出异常了：" + e);
        ModelAndView mv = new ModelAndView(("error"));
        mv.addObject("exception", e);
        return mv;
    }


    @RequestMapping("/testExceptionHandlerExceptionResolver")
    public String testExceptionHandlerExceptionResolver(@RequestParam("i") int i) {
        System.out.println("result: " + (10/i));

        return "success";
    }

	@ResponseStatus(value = HttpStatus.NOT_FOUND, reason = "测试")
    @RequestMapping("testResponseStatusExceptionResolver")
    public String testResponseStatusExceptionResolver(@RequestParam("i") int i) {
        if (i == 13) {
            throw new UserNameNotMatchPasswordExceptionHandler();
        }
        System.out.println("testResponseStatusExceptionResolver...");

        return "success";

    }

	<!-- 配置使用 SimpleMappingExceptionResolver 来映射异常 -->
	<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
		<property name="exceptionAttribute" value="ex"></property>
		<property name="exceptionMappings">
			<props>
				<prop key="java.lang.ArrayIndexOutOfBoundsException">error</prop>
			</props>
		</property>
	</bean>

	@RequestMapping("/testSimpleMappingExceptionResolver")
    public String testSimpleMappingExceptionResolver(@RequestParam("i") int i) {
        String[] values = new String[10];
        System.out.println(values[i]);
        System.out.println("testSimpleMappingExceptionResolver");
        return "success";
    }