Catch parameter parsing exception in Spring 3.0 WebMVC
I use Spring WebMVC to provide a REST API. I use methods like
@RequestMapping("/path({id}") void getById(@PathVariable("id") int id) {} methods.
When the client incorrectly put a string instead of an integer id into the query, I get a NumberFormatException like:
java.lang.NumberFormatException: For input string: "dojo"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Long.parseLong(Long.java:410)
at java.lang.Long.valueOf(Long.java:525)
at org.springframework.util.NumberUtils.parseNumber(NumberUtils.java:158)
at org.springframework.core.convert.support.StringToNumberConverterFactory$StringToNumber.convert(StringToNumberConverterFactory.java:59)
at org.springframework.core.convert.support.StringToNumberConverterFactory$StringToNumber.convert(StringToNumberConverterFactory.java:1)
at org.springframework.core.convert.support.GenericConversionService$ConverterFactoryAdapter.convert(GenericConversionService.java:420)
at org.springframework.core.convert.support.ConversionUtils.invokeConverter(ConversionUtils.java:37)
at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:135)
at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:199)
at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:104)
at org.springframework.beans.SimpleTypeConverter.convertIfNecessary(SimpleTypeConverter.java:47)
at org.springframework.validation.DataBinder.convertIfNecessary(DataBinder.java:526)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolvePathVariable(HandlerMethodInvoker.java:602)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveHandlerArguments(HandlerMethodInvoker.java:289)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:163)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:414)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:402)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:771)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:716)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:647)
My Question is now, how can I elegantly catch it? I know that Spring provides @ExeptionHandler annotations but I don't want to catch the NFE in general. I want to be able to catch all parsing exception in order to present a nice error message to the client.
Any ideas?
Cheers,
Jan
Is that the actual exception? (it doesn't match your code example) Normally one would expect that to be wrapped in org.springframework.beans.TypeMismatchException which is probably specific enough that you could write an @ExceptionHandler method for it.
If that's not specific enough, you will need to forgo the Spring-Magic and just change the parameter type to String + parse it yourself. Then you can handle it any way you like.
I have found solution for your problem here http://www.coderanch.com/t/625951/Spring/REST-request-mapping-parameter-type
Just try
@RequestMapping("/path({id:[d]+}") void getById(@PathVariable("id") int id) {} methods.
And then not valid usage will cause 404. I'm not sure if version 3.0 supports this.
我不是100％确定这是否适用于@PathVaribale ，但通常对于模型绑定，您可以在路径变量旁边使用BindingResult对象，并将模型和解析错误添加到BindingResult/Errors对象。
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