Converter Registration via context-scanning

[objectamit]

Hi,

I've created few custom converters using the Spring converter API and annotated them with @Component. These converters are available in application context but don't get automatically registered with the conversionService unless I do it explicitly which means I can't use spring context/classpath scanning to auto-register custom converters. Any help is welcome.

[dr_pompeii]

These converters are available in application context but don't get automatically registered with the conversionService unless I do it explicitly which means I can't use spring context/classpath scanning to auto-register custom converters

Can you share your configuration? and your solution?

and your error stack trace if you got one?

[objectamit]

Hi,

To illustrate, I'm choosing the mvc-basic example in spring-samples. I created two classes org.springframework.samples.mvc.basic.account.X and org.springframework.samples.mvc.basic.account.Y and then I created a converter using spring API. The code is below

public class X {
	private int value;
	public X(int value) {
		this.value = value;
	}
	public int getValue() {
		return value;
	}
	
}

public class Y {
	private int value;
	public Y(int value) {
		this.value = value;
	}
	public int getValue() {
		return value;
	}
}

@Component
public class MyConverter implements Converter<X, Y> {

	public Y convert(X arg0) {
		Y value = null;
		value = new Y(arg0.getValue());
		return value;
	}

}

After this I copy the src/main/webapp/WEB-INF/spring directory to src/test/resources (This is done to support maven test configuration else I would have to manually create all the configuration myself) and create a junit test shown below

package org.springframework.samples.mvc.basic;

import org.junit.Test;
import static org.junit.Assert.*;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.convert.ConversionService;
import org.springframework.samples.mvc.basic.account.X;
import org.springframework.samples.mvc.basic.account.Y;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@ContextConfiguration(locations={"classpath:spring/app-config.xml"})
@RunWith(SpringJUnit4ClassRunner.class)
public class SimpleTest {
	@Autowired
	private ConversionService service;
	@Test
	public void test() {
		assertTrue(service.canConvert(X.class, Y.class));
	}
}

There's no change in the spring xml files app-config.xml and mvc-config.xml. Now the assertion in my test fails. But if I change the mvc-config.xml declarations to

<?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:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

	<!-- Configures the @Controller programming model -->
	<mvc:annotation-driven conversion-service="conversionService"/>

	<!-- Forwards requests to the "/" resource to the "welcome" view -->
	<mvc:view-controller path="/" view-name="welcome"/>

	<!-- Configures Handler Interceptors -->	
	<mvc:interceptors>
		<!-- Changes the locale when a 'locale' request parameter is sent; e.g. /?locale=de -->
		<bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor" />
	</mvc:interceptors>

	<!-- Saves a locale change using a cookie -->
	<bean id="localeResolver" class="org.springframework.web.servlet.i18n.CookieLocaleResolver" />
<bean id="conversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
		<property name="converters">
			<list>
				<bean class="org.springframework.samples.mvc.basic.account.MyConverter" />
			</list>
		</property>
	</bean>
	<!-- Resolves view names to protected .jsp resources within the /WEB-INF/views directory -->
	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/views/"/>
		<property name="suffix" value=".jsp"/>
	</bean>

</beans>

The assertion succeeds. Thus I've to register my converter manually and not via context-scanning as is desired.