Spring MVC入门（十）：异常处理
异常处理
- 简介
SpringMVC提供了一个处理控制器方法执行过程中所出现的异常的接口：HandlerExceptionResolver
HandlerExceptionResolver接口的实现类有：DefaultHandlerExceptionResolver和
SimpleMappingExceptionResolver
SpringMVC提供了自定义的异常处理器SimpleMappingExceptionResolver
-
双击shift，搜索DefaultHandlerExceptionResolver
-
ctrl + h 选中AbstractHandlerExceptionResolver
-
查看DefaultHandlerExceptionResolver源码，当出现异常时，返回1个新的ModelAndView替换我们自己的ModelAndView
@Override
@Nullable
protected ModelAndView doResolveException(
HttpServletRequest request, HttpServletResponse response, @Nullable Object handler, Exception ex) {
try {
if (ex instanceof HttpRequestMethodNotSupportedException) {
return handleHttpRequestMethodNotSupported(
(HttpRequestMethodNotSupportedException) ex, request, response, handler);
}
else if (ex instanceof HttpMediaTypeNotSupportedException) {
return handleHttpMediaTypeNotSupported(
(HttpMediaTypeNotSupportedException) ex, request, response, handler);
}
else if (ex instanceof HttpMediaTypeNotAcceptableException) {
return handleHttpMediaTypeNotAcceptable(
(HttpMediaTypeNotAcceptableException) ex, request, response, handler);
}
else if (ex instanceof MissingPathVariableException) {
return handleMissingPathVariable(
(MissingPathVariableException) ex, request, response, handler);
}
else if (ex instanceof MissingServletRequestParameterException) {
return handleMissingServletRequestParameter(
(MissingServletRequestParameterException) ex, request, response, handler);
}
else if (ex instanceof ServletRequestBindingException) {
return handleServletRequestBindingException(
(ServletRequestBindingException) ex, request, response, handler);
}
else if (ex instanceof ConversionNotSupportedException) {
return handleConversionNotSupported(
(ConversionNotSupportedException) ex, request, response, handler);
}
else if (ex instanceof TypeMismatchException) {
return handleTypeMismatch(
(TypeMismatchException) ex, request, response, handler);
}
else if (ex instanceof HttpMessageNotReadableException) {
return handleHttpMessageNotReadable(
(HttpMessageNotReadableException) ex, request, response, handler);
}
else if (ex instanceof HttpMessageNotWritableException) {
return handleHttpMessageNotWritable(
(HttpMessageNotWritableException) ex, request, response, handler);
}
else if (ex instanceof MethodArgumentNotValidException) {
return handleMethodArgumentNotValidException(
(MethodArgumentNotValidException) ex, request, response, handler);
}
else if (ex instanceof MissingServletRequestPartException) {
return handleMissingServletRequestPartException(
(MissingServletRequestPartException) ex, request, response, handler);
}
else if (ex instanceof BindException) {
return handleBindException((BindException) ex, request, response, handler);
}
else if (ex instanceof NoHandlerFoundException) {
return handleNoHandlerFoundException(
(NoHandlerFoundException) ex, request, response, handler);
}
else if (ex instanceof AsyncRequestTimeoutException) {
return handleAsyncRequestTimeoutException(
(AsyncRequestTimeoutException) ex, request, response, handler);
}
}
catch (Exception handlerEx) {
if (logger.isWarnEnabled()) {
logger.warn("Failure while trying to resolve exception [" + ex.getClass().getName() + "]", handlerEx);
}
}
return null;
}
- 实现代码
# springmvc配置文件中配置异常处理
<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="java.lang.ArithmeticException">error</prop>
</props>
</property>
<!-- 设置将异常信息共享在请求域中的键 -->
<property name="exceptionAttribute" value="ex"></property>
</bean>
# 编写错误页面
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
出现错误
<p th:text="${ex}"></p>
</body>
</html>
# 模拟1个异常
@RequestMapping("/testExceptionHandler")
public String testExceptionHandler(){
System.out.println(1/0);
return "success";
}
- 注解配置异常处理
# 注释掉springmvc配置文件中配置异常处理
<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="java.lang.ArithmeticException">error</prop>
</props>
</property>
<!-- 设置将异常信息共享在请求域中的键 -->
<property name="exceptionAttribute" value="ex"></property>
</bean>
# 编写错误页面
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
出现错误
<p th:text="${ex}"></p>
</body>
</html>
# 模拟1个异常
@RequestMapping("/testExceptionHandler")
public String testExceptionHandler(){
System.out.println(1/0);
return "success";
}
# 异常处理配置
@ControllerAdvice
public class ExceptionController {
// 出现如下异常时跳转到错误页面
@ExceptionHandler(value = {ArithmeticException.class, NullPointerException.class})
public String testException(Exception ex, Model model){ // 将错误信息通过model设置到域对象中，前端可以获取
model.addAttribute("ex", ex);
return "error";
}
}
