SpringMVC框架下的异常处理

时间:2023-03-08 16:30:12

在eclipse的javaEE环境下:导包。。。。

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. @ExceptionHandler 方法的入参中不能传入 Map. 若希望把异常信息传导页面上, 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 中找不到 @ExceptionHandler 方法来出来当前方法出现的异常,  则将去 @ControllerAdvice 标记的类中查找 @ExceptionHandler 标记的方法来处理异常

web.xml文件配置:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5"> <!-- 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> </web-app>

spring的bean的配置文件:springmvc.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 http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd"> <!-- 配置自动扫描的包 -->
<context:component-scan base-package="com.atguigu.springmvc"></context:component-scan> <!-- 配置视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/"></property>
<property name="suffix" value=".jsp"></property>
</bean> <!--
default-servlet-handler 将在 SpringMVC 上下文中定义一个 DefaultServletHttpRequestHandler,
它会对进入 DispatcherServlet 的请求进行筛查, 如果发现是没有经过映射的请求, 就将该请求交由 WEB 应用服务器默认的
Servlet 处理. 如果不是静态资源的请求,才由 DispatcherServlet 继续处理 一般 WEB 应用服务器默认的 Servlet 的名称都是 default.
若所使用的 WEB 服务器的默认 Servlet 名称不是 default,则需要通过 default-servlet-name 属性显式指定 -->
<mvc:default-servlet-handler/> <mvc:annotation-driven conversion-service="conversionService"></mvc:annotation-driven> <!-- 配置使用 SimpleMappingExceptionResolver 来映射异常 ,出异常时转到error.jsp页面-->
<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
<property name="exceptionAttribute" value="ex"></property>
<property name="exceptionMappings">
<props>
<!-- key异常的全类名 ,并且可以在error页面打印异常-->
<prop key="java.lang.ArrayIndexOutOfBoundsException">error</prop>
</props>
</property>
</bean> </beans>

异常处理类,这个是全局的,只要出现了这个异常,在显示出异常值在对应的页面上;

package com.atguigu.springmvc.test;

import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.ModelAndView; //异常处理类,这个是全局的,只要出现了这个异常,在显示出异常值
@ControllerAdvice
public class SpringMVCTestExceptionHandler { @ExceptionHandler({ArithmeticException.class})
public ModelAndView handleArithmeticException(Exception ex){
System.out.println("----> 出异常了: " + ex);
ModelAndView mv = new ModelAndView("error");
mv.addObject("exception", ex);
return mv;
} }

自定义的异常:页面会显示状态码和异常值

package com.atguigu.springmvc.test;

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus; //自定义的异常:页面会显示状态码和异常值 //value:是一个状态码
@ResponseStatus(value=HttpStatus.FORBIDDEN, reason="用户名和密码不匹配!")
public class UserNameNotMatchPasswordException extends RuntimeException{ /**
*
*/
private static final long serialVersionUID = 1L; }

handler方法:

package com.atguigu.springmvc.test;

@Controller
public class SpringMVCTest { @Autowired
private EmployeeDao employeeDao;
//这个需要在springmvc.xml文件中进行配置,出现异常后转向到那个页面
@RequestMapping("/testSimpleMappingExceptionResolver")
public String testSimpleMappingExceptionResolver(@RequestParam("i") int i){
String [] vals = new String[10];
System.out.println(vals[i]);
return "success";
} //对spring的一些特殊异常进行处理,如超链接是get请求,而这儿是post请求,所以会出现异常,显示在页面上
@RequestMapping(value="/testDefaultHandlerExceptionResolver",method=RequestMethod.POST)
public String testDefaultHandlerExceptionResolver(){
System.out.println("testDefaultHandlerExceptionResolver...");
return "success";
}
//类方法,的自定义异常
@ResponseStatus(reason="测试",value=HttpStatus.NOT_FOUND)
@RequestMapping("/testResponseStatusExceptionResolver")
public String testResponseStatusExceptionResolver(@RequestParam("i") int i){
if(i == 13){
throw new UserNameNotMatchPasswordException();
}
System.out.println("testResponseStatusExceptionResolver..."); return "success";
} //异常处理 // @ExceptionHandler({RuntimeException.class})
// public ModelAndView handleArithmeticException2(Exception ex){
// System.out.println("[出异常了]: " + ex);
// ModelAndView mv = new ModelAndView("error");
// mv.addObject("exception", ex);
// return mv;
// } /**
* 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. @ExceptionHandler 方法的入参中不能传入 Map. 若希望把异常信息传导页面上, 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 中找不到 @ExceptionHandler 方法来出来当前方法出现的异常,
* 则将去 @ControllerAdvice 标记的类中查找 @ExceptionHandler 标记的方法来处理异常.
*/
// @ExceptionHandler({ArithmeticException.class})
// public ModelAndView handleArithmeticException(Exception ex){
// System.out.println("出异常了: " + ex);
// ModelAndView mv = new ModelAndView("error");
// mv.addObject("exception", ex);
// return mv;
// } @RequestMapping("/testExceptionHandlerExceptionResolver")
public String testExceptionHandlerExceptionResolver(@RequestParam("i") int i){
System.out.println("result: " + (10 / i));
return "success";
} }

index.jsp页面:

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body> <br><br>
<a href="testExceptionHandlerExceptionResolver?i=10">Test ExceptionHandlerExceptionResolver</a> <br><br>
<a href="testResponseStatusExceptionResolver?i=10">Test ResponseStatusExceptionResolver</a> <br><br>
<a href="testDefaultHandlerExceptionResolver">Test DefaultHandlerExceptionResolver</a> <br><br>
<a href="testSimpleMappingExceptionResolver?i=2">Test SimpleMappingExceptionResolver</a>
</body>
</html>

出现异常转向的页面error.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body> <h4>Error Page</h4> ${requestScope.exception } </body>
</html>