잊지 않겠습니다.

<mvc:annotation-driven>를 사용할 때, @InitBinder에서 ConversionService를 등록할 때 에러가 발생하는 이유.

Java 2013. 1. 3. 00:03
<mvc:annotation-driven>
이 설정될 경우, 여기에 따른 여러가지 설정이 많이 이루어지게 된다. 
먼저 Spring 문서에 따르면, 

 1. Support for Spring 3′s Type ConversionService in addition to JavaBeans PropertyEditors during Data Binding. A ConversionService instance produced by the org.springframework.format.support.FormattingConversionServiceFactoryBean is used by default. This can be overriden by setting the conversion-service attribute. 
2. Support for formatting Number fields using the @NumberFormat annotation 
3. Support for formatting Date, Calendar, Long, and Joda Time fields using the @DateTimeFormat annotation, if Joda Time is present on the classpath. 
4. Support for validating @Controller inputs with @Valid, if a JSR-303 Provider is present on the classpath. The validation system can be explicitly configured by setting the validator attribute. 
5. Support for reading and writing XML, if JAXB is present on the classpath. 
6. Support for reading and writing JSON, if Jackson is present on the classpath. 

와 같은 일들이 벌어지게 된다. 

여기서 주의할 점은 1번 항목. ConversionService가 default로 설정이 된다는것이다. ConversionService가 이미 설정이 되어 있기 때문에 Spring source에서 보면 다음과 같은 항목에 의하여 에러가 발생하게 된다.
view source
print?
1.public void setConversionService( ConversionService conversionService ) {
2.       Assert .state ( this. conversionService == null, "DataBinder is already initialized with ConversionService");
3.       this .conversionService = conversionService ;
4.       if ( this .bindingResult != null && conversionService != null ) {
5.              this .bindingResult . initConversion( conversionService );
6.       }
7.}
따라서, Converter 를 이용한 @InitBinder는 사용할 수 없게 되고 에러를 발생시키게 된다. 이 경우에, @InitBinder를 이용하기 위해서는 PropertyEditorSupport를 상속받아 등록시키는 방법을 사용할 수 밖에 없게 된다. 을 통해서 설정되는 것을 xml로 표현하면 다음과 같다.
view source
print?
01.    <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping">
02.        <property name="order" value="0">
03.    </property></bean>
04.      
05.    <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean">
06.    <bean id="conversion-service" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
07. 
08.    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
09.        <property name="webBindingInitializer">
10.            <bean class="org.springframework.web.bind.support.ConfigurableWebBindingInitializer">
11.                <property name="validator" ref="validator">
12.                <property name="conversionService" ref="conversion-service">
13.            </property></property></bean>
14.        </property>
15.        <property name="messageConverters">
16.            <list>
17.                <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter">
18.                <bean class="org.springframework.http.converter.StringHttpMessageConverter">
19.                    <property name="writeAcceptCharset" value="false">
20.                </property></bean>
21.                <bean class="org.springframework.http.converter.ResourceHttpMessageConverter">
22.                <bean class="org.springframework.http.converter.xml.SourceHttpMessageConverter">
23.                <bean class="org.springframework.http.converter.xml.XmlAwareFormHttpMessageConverter">
24.<!--                <bean class="org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter" />-->
25.<!--                <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" />-->
26.<!--                <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" />-->
27.<!--                <bean class="org.springframework.http.converter.feed.AtomFeedHttpMessageConverter" />-->
28.<!--                <bean class="org.springframework.http.converter.feed.RssChannelHttpMessageConverter" />-->
29.            </bean></bean></bean></bean></list>
30.        </property>
31.    </bean>
32. 
33.    <bean class="org.springframework.web.servlet.handler.MappedInterceptor">
34.        <constructor-arg index="0"><null></null></constructor-arg>
35.        <constructor-arg index="1">
36.            <bean class="org.springframework.web.servlet.handler.ConversionServiceExposingInterceptor">
37.                <constructor-arg index="0" ref="conversion-service">
38.            </constructor-arg></bean>
39.        </constructor-arg>
40.    </bean>
41.</bean></bean>
위에서 주석처리 되어 있는 항목들은 해당 외부 라이브러리들이 존재하면 사용되게 된다.



저작자표시 비영리 변경금지
Posted by Y2K
,

티스토리툴바