Set中的推土机映射 <Object> 列出 <ENUM>

Question

I want to map a Set of objects to a List of Enums. I have already created a custom converter to convert enums to their string equivalents. When I try to run Junits which initiates the aforementioned conversion Dozer throws the following error :

org.dozer.MappingException: java.lang.NoSuchMethodException: 

For Eg : I want to convert Set < Foo> to List< FOO>

class Foo{
    private String FOO; // this contains same data as the enum FOO
    private String foo1;
}

enum FOO { 
    A,B; 
}

Answer 1

It would have been better if you had shown the full stack trace, mapping xml, customer converter, and relevant codes. I can hazard a guess that you're getting NoSuchMethodException because you're using the enum constructor wrongly.

However, here's a CustomConverter which successfully maps a Set of Objects to a List of enums (I've labelled the enum as 'Bar' instead of 'FOO'):

public class EnumClassConverter implements CustomConverter{

    public Object convert(Object dest, Object source, Class<?> arg2, Class<?> arg3) {
        if (source == null)
            return null;

        if (source instanceof Set<?>){
            Set<Foo> setOfFoos = (Set<Foo>) source;
            List<Bar> listOfBars = new ArrayList<Bar>();
            for (Foo f:setOfFoos){
                if (f.getFOO()=="A") listOfBars.add(Bar.A);
                else listOfBars.add(Bar.B);
            }
            return listOfBars;
        }
        else if (source instanceof List<?>){
            List<Bar> listOfBars = (List<Bar>) source;
            Set<Foo> setOfFoos = new HashSet<Foo>();

            for (Bar b : listOfBars){
                Foo f = new Foo();
                if (b ==Bar.A){
                    f.setFOO("A");
                }
                else f.setFOO("B");
                setOfFoos.add(f);
            }
            return setOfFoos;
        }
        else {
          throw new MappingException("Converter EnumClassConverter "
              + "used incorrectly. Arguments passed in were:"
              + dest + " and " + source);
            }
    }

}

and the mapping xml:

<?xml version="1.0" encoding="UTF-8"?>
<mappings xmlns="http://dozer.sourceforge.net"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://dozer.sourceforge.net
          http://dozer.sourceforge.net/schema/beanmapping.xsd">
    <mapping>
        <class-a>beans.FooContainer</class-a>
        <class-b>beans.BarContainer</class-b>
        <field custom-converter="converter.EnumClassConverter" >
            <a>fooSet</a>
            <b>listOfBars</b>
        </field>        
    </mapping>
</mappings>