org.springframework.web.servlet.HandlerExceptionResolver 接口用于解析请求处理过程中所产生的异常。开发者可以开发该接口的实现类进行 Spring MVC 应用的异常统一处理。
在 springMVCDemo10 应用的 exception 包中创建一个 HandlerExceptionResolver 接口的实现类 MyExceptionHandler,具体代码如下:
- package exception;
- import java.sql.SQLException;
- import java.util.HashMap;
- import java.util.Map;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import org.springframework.web.servlet.HandlerExceptionResolver;
- import org.springframework.web.servlet.ModelAndView;
- public class MyExceptionHandler implements HandlerExceptionResolver {
- @Override
- public ModelAndView resolveException(HttpServletRequest arg0,
- HttpServletResponse arg1, Object arg2, Exception arg3) {
- Map<String, Object> model = new HashMap<String, Object>();
- model.put("ex", arg3);
- // 根据不同错误转向不同页面(统一处理),即异常与View的对应关系
- if (arg3 instanceof MyException) {
- return new ModelAndView("my-error", model);
- } else if (arg3 instanceof SQLException) {
- return new ModelAndView("sql-error", model);
- } else {
- return new ModelAndView("error", model);
- }
- }
- }
需要将实现类 MyExceptionHandler 在配置文件中托管给 Spring MVC 框架才能进行异常的统一处理,配置代码为 <bean class="exception.MyExceptionHandler"/>。
在实现 HandlerExceptionResolver 接口统一处理异常时将配置文件的代码修改如下:
- <?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"
- xsi:schemaLocation="
- http://www.springframework.org/schema/beans
- http://www.springframework.org/schema/beans/spring一beans.xsd
- http://www.springframework.org/schema/context
- http://www.springframework.org/schema/context/spring-context.xsd">
- <!-- 使用扫描机制扫描包 -->
- <context:component-scan base-package="controller" />
- <context:component-scan base-package="service" />
- <context:component-scan base-package="dao" />
- <!-- 配置视图解析器 -->
- <bean
- class="org.springframework.web.servlet.view.InternalResourceViewResolver"
- id="internalResourceViewResolver">
- <!--前缀 -->
- <property name="prefix" value="/WEB-INF/jsp/" />
- <!-- 后缀 -->
- <property name="suffix" value=".jsp" />
- </bean>
- <!--托管MyExceptionHandler-->
- <bean class="exception.MyExceptionHandler"/>
- </beans>
发布 springMVCDemo10 应用到 Tomcat 服务器并启动服务器,然后即可通过地址“http://localhost:8080/springMVCDemo10/”测试应用。