Tag Archives: Spring

ConverterNotFound Using Spring Roo

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Using Roo has been really awesome! I would recommend it to anyone starting a web project for the first time that really wanted to use Spring and Java.

Just ran into this error tonight and thought I would blog a little bit about it in case others run into the same error… *plus* I wanted to show a bit of this new Google Guava project!

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org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from 'java.util.Se
t' 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)

This meant that we need a converter for the show view since the default create from Roo does not take care of the ONE_TO_MANY relationship. Below is the code that was needed in my case.

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/**
 * A central place to register application Converters and Formatters.
 */
@RooConversionService
public class ApplicationConversionServiceFactoryBean extends FormattingConversionServiceFactoryBean {

    Converter<Set<Property>, String> getPropertySetConverter() {
        return new Converter<Set<Property>, String>() {
            public String convert(Set<Property> properties) {
                return Joiner.on(",").join(properties.toArray());      // 1
            }
        };
    }
  @Override
  protected void installFormatters(FormatterRegistry registry) {
    super.installFormatters(registry);
    registry.addConverter(getPropertySetConverter());
  }
 
}

Notice the line:

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return Joiner.on(",").join(properties.toArray());      // 1

This is using the Google Guava project to create a String instead of using the old school StringBuilder approach.