1.自定义拦截器
1.基本介绍
1.说明
2.自定义拦截器的三个方法
3.流程图
2.快速入门
1.Myinterceptor01.java
package com.sun.web.interceptor;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@Component
public class Myinterceptor01 implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("preHandle");
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
System.out.println("postHandle");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
System.out.println("afterCompletion");
}
}
2.FurnHandler.java
package com.sun.web.interceptor;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class FurnHandler {
@RequestMapping("/hi")
public String hi() {
System.out.println("hi方法被调用");
return "success";
}
@RequestMapping("/hello")
public String hello() {
System.out.println("hello方法被调用");
return "success";
}
}
3.springDispatcherServlet-servlet.xml配置拦截器
<mvc:interceptors>
<ref bean="myinterceptor01"/>
</mvc:interceptors>
4.单元测试
3.拦截特定路径
1.拦截指定路径
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/hi"/>
<ref bean="myinterceptor01"/>
</mvc:interceptor>
</mvc:interceptors>
2.通配符配置路径
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/h*"/>
<mvc:exclude-mapping path="/hi"/>
<ref bean="myinterceptor01"/>
</mvc:interceptor>
</mvc:interceptors>
4.细节说明
5.多个拦截器
1.执行流程图
2.应用实例
1.FurnHandler.java目标方法
@RequestMapping("/topic")
public String topic() {
System.out.println("topic执行!");
return "success";
}
2.拦截器
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
String topic = request.getParameter("topic");
if (topic.equals("topic")) {
response.setContentType("text/html;charset=utf-8");
response.getWriter().write("<h1>请不要乱说话!!</h1>");
}
return false;
}
3.结果展示
2.异常处理
1.基本介绍
2.局部异常处理器
1.需求分析
2.抛出问题
1.MyExceptionHandler.java
package com.sun.web.exception;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class MyExceptionHandler {
@RequestMapping("/getNum/{num}")
public String getNUm(@PathVariable("num") Integer num) {
System.out.println(10 / num);
return "success";
}
}
2.不处理异常则交给tomcat处理
3.局部异常实例
1.MyExceptionHandler.java
package com.sun.web.exception;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import javax.servlet.http.HttpServletRequest;
@Controller
public class MyExceptionHandler {
@RequestMapping("/getNum/{num}")
public String getNUm(@PathVariable("num") Integer num) {
System.out.println(10 / num);
return "success";
}
@ExceptionHandler({ArithmeticException.class, NullPointerException.class})
public String exceptionHandler(Exception ex, HttpServletRequest request) {
System.out.println("异常的信息=" + ex.getMessage());
request.setAttribute("reason", ex.getMessage());
return "exception_mes";
}
}
2.exception_mes.jsp
<%--
Date: 2024/3/1
Time: 8:47
User: 孙显圣
Version:1.0
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h3>出现异常</h3>
<h4>异常信息是${requestScope.reason}</h4>
</body>
</html>
3.结果展示
3.全局异常处理器
1.基本介绍
2.全局异常实例
1.MyGlobalException.java
package com.sun.web.exception;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import javax.servlet.http.HttpServletRequest;
@ControllerAdvice
public class MyGlobalException {
@ExceptionHandler(ArithmeticException.class)
public String globalException(Exception ex, HttpServletRequest request) {
System.out.println("全局异常信息是=" + ex.getMessage());
request.setAttribute("reason", ex.getMessage());
return "global_exception";
}
}
2.global_exception.jsp
<%--
Date: 2024/3/1
Time: 9:02
User: 孙显圣
Version:1.0
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h3>出现异常</h3>
<h4>全局异常信息是${requestScope.reason}</h4>
</body>
</html>
3.结果展示
3.细节说明
1.局部异常优先级高于全局异常
2.处理异常机制
- 先从发生异常的方法所在的类中查找有
@ExceptionHandler
注解的方法,如果异常不匹配则进行下一步
- 从有
@ControllerAdvice
注解的类查找有@ExceptionHandler
注解的方法,如果匹配异常则处理,无法匹配则交给tomcat处理
4.自定义异常
1.基本介绍
2.自定义异常应用实例
1.SelfException.java
package com.sun.web.exception;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;
@ResponseStatus(reason = "年龄需要在1-120之间", value = HttpStatus.BAD_REQUEST)
public class SelfException extends RuntimeException{
}
2.selfex.java
package com.sun.web.exception;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class selfex {
@RequestMapping("/selfex")
public void ex() {
throw new SelfException();
}
}
3.结果展示
3.可以使用有参构造,抛出异常交给异常处理器接管
1.SelfException.java
package com.sun.web.exception;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;
@ResponseStatus(reason = "年龄需要在1-120之间", value = HttpStatus.BAD_REQUEST)
public class SelfException extends RuntimeException{
public SelfException() {
}
public SelfException(String message) {
super(message);
}
}
2.selfex.java抛出自定义异常并制定message
package com.sun.web.exception;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class selfex {
@RequestMapping("/selfex")
public void ex() {
throw new SelfException("年龄需要在1-100");
}
}
3.MyGlobalException.java捕获自定义异常
package com.sun.web.exception;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import javax.servlet.http.HttpServletRequest;
@ControllerAdvice
public class MyGlobalException {
@ExceptionHandler(SelfException.class)
public String selfex(Exception ex, HttpServletRequest request) {
request.setAttribute("reason", ex.getMessage());
return "global_exception";
}
}
4.结果展示
5.统一异常处理器
1.基本介绍
2.需求分析
3.具体实现
1.MyExceptionHandler.java抛出数组越界异常
package com.sun.web.exception;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class MyExceptionHandler {
@RequestMapping("/arr")
public String array() {
int[] ints = {1, 2, 3};
System.out.println(ints[1222]);
return "success";
}
}
2.springDispatcherServlet-servlet.xml配置统一异常处理器
<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver" id="exceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="java.lang.ArrayIndexOutOfBoundsException">arrEx</prop>
</props>
</property>
</bean>
3.arrEx.jsp异常处理页面
<%--
Date: 2024/3/1
Time: 10:02
User: 孙显圣
Version:1.0
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h1>数组越界异常</h1>
</body>
</html>
4.结果展示
6.对未知异常进行统一处理
1.具体实现
1.MyExceptionHandler.java抛出异常
package com.sun.web.exception;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class MyExceptionHandler {
@RequestMapping("/test")
public String test() {
String str = "hello";
char c = str.charAt(10);
return "success";
}
}
2.springDispatcherServlet-servlet.xml修改统一异常处理器
<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver" id="exceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="java.lang.ArrayIndexOutOfBoundsException">arrEx</prop>
<prop key="java.lang.Exception">allEx</prop>
</props>
</property>
</bean>
3.allEx.jsp所有未知异常的处理
<%--
Date: 2024/3/1
Time: 10:12
User: 孙显圣
Version:1.0
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h1>所有未知异常的处理界面</h1>
</body>
</html>
4.结果展示
7.异常处理的优先级
1.局部异常处理器
- 方法上加@ExceptionHandler({ArithmeticException.class, NullPointerException.class}) //参数是一个数组,可以接受多个异常类型
2.全局异常处理器
- 类上加@ControllerAdvice //表示这个是处理全局异常的类
- 方法上加@ExceptionHandler({ArithmeticException.class, NullPointerException.class}) //参数是一个数组,可以接受多个异常类型
3.统一异常处理器
- 匹配方式是匹配尽可能具体的类型,跟配置的顺序无关
- 在Spring配置文件中配置
<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver" id="exceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="java.lang.ArrayIndexOutOfBoundsException">arrEx</prop>
<prop key="java.lang.Exception">allEx</prop>
</props>
</property>
</bean>
4.Tomcat默认机制
3.springMVC阶段的配置文件
1.springDispatcherServlet-servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:component-scan base-package="com.sun.web"/>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver">
<property name="prefix" value="/WEB-INF/pages/"/>
<property name="suffix" value=".jsp"/>
</bean>
<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basename" value="i18n"></property>
</bean>
<bean class="org.springframework.web.multipart.commons.CommonsMultipartResolver" id="multipartResolver"></bean>
<mvc:annotation-driven></mvc:annotation-driven>
<mvc:default-servlet-handler/>
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/topic"/>
<ref bean="myinterceptor01"/>
</mvc:interceptor>
</mvc:interceptors>
<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver" id="exceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="java.lang.ArrayIndexOutOfBoundsException">arrEx</prop>
<prop key="java.lang.Exception">allEx</prop>
</props>
</property>
</bean>
</beans>
2.web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<filter>
<filter-name>CharacterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CharacterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<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>
<servlet>
<servlet-name>springDispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springDispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>