java - 推土机 5.3.2。以编程方式设置自定义转换器？

Question

如何以编程方式为推土机设置自定义转换器？以下代码不起作用:

自定义转换器实现:

class ConverterImpl extends DozerConverter<A, B> {

ConverterImpl() {
    super(A.class, B.class);
}

@Override
public B convertTo(A source, B destination) {
    return destination;
}

@Override
public A convertFrom(B source, A destination) {
    return destination;
}
}

测试代码:

DozerBeanMapper mapper = new DozerBeanMapper();
mapper.setCustomConverters(Collections.<CustomConverter>singletonList(new ConverterImpl()));
A a = new A(); 
B b = mapper.map(a, A.class);  

运行上面的代码后，自定义转换器不会被调用。怎么了？

Answer 1

看起来您必须实际添加一个特定的映射，不幸的是您只能使用编程 API 指定字段级转换器，而不是类级转换器。因此，如果将 A 和 B 类包装在容器类中，则可以为 A 和 B 字段指定一个映射。

例如，以下冗长的代码按预期工作:

public class DozerMap {

   public static class ContainerA {
      private A a;
      public A getA() { return a; }
      public void setA(A a) { this.a = a; }
   }

   public static class ContainerB {
      private B b;
      public B getB() { return b; }
      public void setB(B b) { this.b = b; }
   }

   private static class A { };

   private static class B { };

   static class ConverterImpl extends DozerConverter<A, B> {

      ConverterImpl() {
         super(A.class, B.class);
      }

      @Override
      public B convertTo(A source, B destination) {
         Logger.getAnonymousLogger().info("Invoked");
         return destination;
      }

      @Override
      public A convertFrom(B source, A destination) {
         Logger.getAnonymousLogger().info("Invoked");
         return destination;
      }
   }

   public static void main(String[] args) {

      DozerBeanMapper mapper = new DozerBeanMapper();
      mapper.setCustomConverters(Collections.<CustomConverter> singletonList(new ConverterImpl()));
      BeanMappingBuilder foo = new BeanMappingBuilder() {

         @Override
         protected void configure() {
            mapping(ContainerA.class, ContainerB.class).fields("a", "b", FieldsMappingOptions.customConverter(ConverterImpl.class));
         }
      };
      mapper.setMappings(Collections.singletonList(foo));
      ContainerA containerA = new ContainerA();
      containerA.a = new A();
      ContainerB containerB = mapper.map(containerA, ContainerB.class);
   }
}