Conversion from String to MediaType should not fail with default ConversionService [SPR-7282]

[spring-projects-issues]

Gerrit Brehmer opened SPR-7282 and commented

Because MediaType has an special constructor with only one String parameter, the ObjectToObjectConverter thought, that he can convert the String value "application/xml" to an MediaType. So ObjectToObjectConverter will call the constructor and conversion fails, because this constructor only need the primary content type:

Exception:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'contentNegotiatingViewResolver' defined in ServletContext resource [/WEB-INF/app-servlet.xml]: Initialization of bean failed; nested exception is org.springframework.core.convert.ConversionFailedException: Unable to convert value application/xml from type 'java.lang.String' to type 'org.springframework.http.MediaType'; nested exception is org.springframework.core.convert.ConversionFailedException: Unable to convert value application/xml from type 'java.lang.String' to type 'org.springframework.http.MediaType'; nested exception is java.lang.reflect.InvocationTargetException
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:527)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:563)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:872)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:423)
	at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:442)
	at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:458)
	at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:339)
	at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:306)
	at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:127)
	at javax.servlet.GenericServlet.init(GenericServlet.java:212)
	at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1139)
	at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:966)
	at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:3996)
	at org.apache.catalina.core.StandardContext.start(StandardContext.java:4266)
	at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1014)
	at org.apache.catalina.core.StandardHost.start(StandardHost.java:736)
	at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1014)
	at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
	at org.apache.catalina.core.StandardService.start(StandardService.java:448)
	at org.apache.catalina.core.StandardServer.start(StandardServer.java:700)
	at org.apache.catalina.startup.Catalina.start(Catalina.java:552)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:592)
	at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:295)
	at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:433)
Caused by: org.springframework.core.convert.ConversionFailedException: Unable to convert value application/xml from type 'java.lang.String' to type 'org.springframework.http.MediaType'; nested exception is org.springframework.core.convert.ConversionFailedException: Unable to convert value application/xml from type 'java.lang.String' to type 'org.springframework.http.MediaType'; nested exception is java.lang.reflect.InvocationTargetException
	at org.springframework.core.convert.support.ConversionUtils.invokeConverter(ConversionUtils.java:40)
	at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:138)
	at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:201)
	at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:155)
	at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:461)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCapableBeanFactory.java:1363)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1322)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1076)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
	... 31 more
Caused by: org.springframework.core.convert.ConversionFailedException: Unable to convert value application/xml from type 'java.lang.String' to type 'org.springframework.http.MediaType'; nested exception is java.lang.reflect.InvocationTargetException
	at org.springframework.core.convert.support.ObjectToObjectConverter.convert(ObjectToObjectConverter.java:82)
	at org.springframework.core.convert.support.ConversionUtils.invokeConverter(ConversionUtils.java:37)
	... 39 more
Caused by: java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:501)
	at org.springframework.core.convert.support.ObjectToObjectConverter.convert(ObjectToObjectConverter.java:70)
	... 40 more
Caused by: java.lang.IllegalArgumentException: Invalid token character '/' in token "application/xml"
	at org.springframework.http.MediaType.checkToken(MediaType.java:286)
	at org.springframework.http.MediaType.<init>(MediaType.java:257)
	at org.springframework.http.MediaType.<init>(MediaType.java:207)
	at org.springframework.http.MediaType.<init>(MediaType.java:196)
	... 45 more

With disabled ConversionService, the value will be converted by MediaTypeEditor, which uses the MediaType.parseMediaType method.
I think the behauvior should be the same like mediaTypes-parameter map (ContentNegotiatingViewResolver), where Strings must be used.

Example spring config:

<bean id="contentNegotiatingViewResolver" class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
  <property name="defaultContentType" value="application/xml"/>
  <property name="mediaTypes">
    <map>
      <entry key="xml" value="application/xml" />
      <entry key="json" value="application/json" />
    </map>
  </property>
</bean>

---

Affects: 3.0.2

Referenced from: commits 96b1dc9

[spring-projects-issues]

Juergen Hoeller commented

Aside from the specific MediaType issue, there is definitely an issue with error reporting here since the InvocationTargetException shouldn't be visible in that stacktrace. We'll have a quick look at this for 3.0.3 still.

Juergen

[spring-projects-issues]

Juergen Hoeller commented

Fixed through the addition of a 'valueOf' method, simply delegating to the existing parseMediaType method. The 'valueOf' convention automatically overrides the MediaType(String) constructor according to ConversionService rules.

Also fixed the InvocationTargetException problem, wrapping the underlying exception directly now.

Juergen

[spring-projects-issues]

Rajesh commented

This has resurfaced in 3.1.3.RELEASE