Webflow conversion service not used by Spring EL

[pcaetano]

Hi,

I'm having a problem rendering jspx in webflow environment because of the following error:

SEVERE: Servlet.service() for servlet jsp threw exception
org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from 'domain.shared.Status' to 'java.lang.String'
	at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:181)
	at org.springframework.expression.spel.support.StandardTypeConverter.convertValue(StandardTypeConverter.java:66)
	at org.springframework.expression.common.ExpressionUtils.convertTypedValue(ExpressionUtils.java:67)
	at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:98)
	at org.springframework.web.servlet.tags.EvalTag.doEndTag(EvalTag.java:122)
	at org.apache.jsp.tag.web.form.fields.display_tagx._jspx_meth_spring_005feval_005f0(display_tagx.java:794)
	at org.apache.jsp.tag.web.form.fields.display_tagx._jspx_meth_c_005fotherwise_005f0(display_tagx.java:767)
	at org.apache.jsp.tag.web.form.fields.display_tagx._jspx_meth_c_005fchoose_005f0(display_tagx.java:562)
	at org.apache.jsp.tag.web.form.fields.display_tagx._jspx_meth_c_005fif_005f0(display_tagx.java:283)
	at org.apache.jsp.tag.web.form.fields.display_tagx.doTag(display_tagx.java:230)

Using the same tag in a Spring MVC environment works fine (the converter is used as expected).

I'm working with:
Spring Roo 1.1
Spring 3.0.5
Spring webflow 2.2.1
Tiles

The relevant webflow configuration is:

...
    <webflow:flow-builder-services id="flowBuilderServices"	view-factory-creator="mvcViewFactoryCreator"
        conversion-service="webflowConversionService"  development="true" />

    <bean id="coreConversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
        <property name="converters">
            <set>
                <bean class="converter.StatusConverter" /> <-- my converter
            </set>
        </property>
    </bean>

    <bean id="webflowConversionService" class="org.springframework.binding.convert.service.DefaultConversionService">
        <constructor-arg ref="coreConversionService"/>
    </bean>
...

Using the debugger, I can see the problem is the conversion service is not found by the EvalTag in the PageContext, so a new one is created and used (with the default converters only):
EvalTag class:

	private EvaluationContext createEvaluationContext(PageContext pageContext) {
		StandardEvaluationContext context = new StandardEvaluationContext();
		context.addPropertyAccessor(new JspPropertyAccessor(pageContext));
		context.setBeanResolver(new BeanFactoryResolver(getRequestContext().getWebApplicationContext()));
		ConversionService conversionService = getConversionService(pageContext);
		if (conversionService != null) {
			context.setTypeConverter(new StandardTypeConverter(conversionService));
		}
		return context;
	}
	
	private ConversionService getConversionService(PageContext pageContext) {
		return (ConversionService) pageContext.getRequest().getAttribute(ConversionService.class.getName());
	}

in the snippet above, the problem is that "getConversionService(PageContext)" returns null when the JSP is rendered in webflow. In Spring MVC, the same method returns the "coreConversionService".

Do you know why? What am I missing?
I also tried to define an ExpressionParser wired with my conversion service (that I think is not needed), but didn't work...

    <bean id="webflowExpressionParser" class="org.springframework.webflow.expression.spel.WebFlowSpringELExpressionParser">
        <constructor-arg>
            <bean class="org.springframework.expression.spel.standard.SpelExpressionParser" />
        </constructor-arg>
        <constructor-arg ref="webflowConversionService" />
    </bean>

Thanks you.

[srufle]

I am having the same issue in Webflow 2.2.0 I tried following the steps in the following and still do not get my custom converters registered.
http://static.springsource.org/sprin...l/ch05s07.html

Hi,

I'm having a problem rendering jspx in webflow environment because of the following error:

SEVERE: Servlet.service() for servlet jsp threw exception
org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from 'domain.shared.Status' to 'java.lang.String'
	at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:181)
	at org.springframework.expression.spel.support.StandardTypeConverter.convertValue(StandardTypeConverter.java:66)
	at org.springframework.expression.common.ExpressionUtils.convertTypedValue(ExpressionUtils.java:67)
	at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:98)
	at org.springframework.web.servlet.tags.EvalTag.doEndTag(EvalTag.java:122)
	at org.apache.jsp.tag.web.form.fields.display_tagx._jspx_meth_spring_005feval_005f0(display_tagx.java:794)
	at org.apache.jsp.tag.web.form.fields.display_tagx._jspx_meth_c_005fotherwise_005f0(display_tagx.java:767)
	at org.apache.jsp.tag.web.form.fields.display_tagx._jspx_meth_c_005fchoose_005f0(display_tagx.java:562)
	at org.apache.jsp.tag.web.form.fields.display_tagx._jspx_meth_c_005fif_005f0(display_tagx.java:283)
	at org.apache.jsp.tag.web.form.fields.display_tagx.doTag(display_tagx.java:230)

Using the same tag in a Spring MVC environment works fine (the converter is used as expected).

I'm working with:
Spring Roo 1.1
Spring 3.0.5
Spring webflow 2.2.1
Tiles

The relevant webflow configuration is:

...
    <webflow:flow-builder-services id="flowBuilderServices"	view-factory-creator="mvcViewFactoryCreator"
        conversion-service="webflowConversionService"  development="true" />

    <bean id="coreConversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
        <property name="converters">
            <set>
                <bean class="converter.StatusConverter" /> <-- my converter
            </set>
        </property>
    </bean>

    <bean id="webflowConversionService" class="org.springframework.binding.convert.service.DefaultConversionService">
        <constructor-arg ref="coreConversionService"/>
    </bean>
...

Using the debugger, I can see the problem is the conversion service is not found by the EvalTag in the PageContext, so a new one is created and used (with the default converters only):
EvalTag class:

	private EvaluationContext createEvaluationContext(PageContext pageContext) {
		StandardEvaluationContext context = new StandardEvaluationContext();
		context.addPropertyAccessor(new JspPropertyAccessor(pageContext));
		context.setBeanResolver(new BeanFactoryResolver(getRequestContext().getWebApplicationContext()));
		ConversionService conversionService = getConversionService(pageContext);
		if (conversionService != null) {
			context.setTypeConverter(new StandardTypeConverter(conversionService));
		}
		return context;
	}
	
	private ConversionService getConversionService(PageContext pageContext) {
		return (ConversionService) pageContext.getRequest().getAttribute(ConversionService.class.getName());
	}

in the snippet above, the problem is that "getConversionService(PageContext)" returns null when the JSP is rendered in webflow. In Spring MVC, the same method returns the "coreConversionService".

Do you know why? What am I missing?
I also tried to define an ExpressionParser wired with my conversion service (that I think is not needed), but didn't work...

    <bean id="webflowExpressionParser" class="org.springframework.webflow.expression.spel.WebFlowSpringELExpressionParser">
        <constructor-arg>
            <bean class="org.springframework.expression.spel.standard.SpelExpressionParser" />
        </constructor-arg>
        <constructor-arg ref="webflowConversionService" />
    </bean>

Thanks you.