使用 ModelMapper 映射抽象类型的字段
Using ModelMapper to map field of abstract type
我有以下 class 层次结构:
public abstract class Base {
protected Boolean baseBoolean;
}
public class A extends Base {
private BigDecimal amount;
}
并尝试将 DTO 映射到实体
public class DTO {
private Base details;
}
public class Entity {
private Base details;
}
并配图如下:
public static void main(String[] args) {
ModelMapper modelMapper = new ModelMapper();
modelMapper.getConfiguration().setDeepCopyEnabled(true);
A a = new A();
a.setAmount(BigDecimal.ONE);
a.setBaseBoolean(true);
DTO request = DTO.builder().base(a).build();
Entity entity = modelMapper.map(request, Entity.class);
System.out.println(entity);
}
我在详细信息字段中收到带有 A 或 B 的 DTO,这是用调试器检查的。但是模型映射器抛出
Failed to instantiate instance of destination
org.package.Base.
Ensure that
org.package.Base has a
non-private no-argument constructor.
我尝试使用显式提供程序(未用于此映射):
modelMapper.typeMap(A.class, Base.class).setProvider(new Provider<Base>() {
@Override
public Base get(ProvisionRequest<Base> r) {
return new A();
}
});
我也试过像这样实现自定义转换器(也没有执行):
modelMapper.typeMap(A.class, Base.class).setConverter(new Converter<A, Base>() {
@Override
public Base convert(MappingContext<A, Base> mappingContext) {
return modelMapper.map(mappingContext.getSource(), A.class);
}
});
modelmapper 似乎不将此类型映射用于字段,仅用于层次结构的根。
在这种情况下如何映射 class 层次结构?
如您所见,启用深层复制时会出现问题:modelMapper.getConfiguration().setDeepCopyEnabled(true)
。
一个解决方案是定义一个 Converter<Base, Base>
如下:
ModelMapper modelMapper = new ModelMapper();
modelMapper.getConfiguration().setDeepCopyEnabled(true); // this triggers the problem
// the converter resolves it
Converter<Base, Base> baseBaseConverter = context ->
modelMapper.map(context.getSource(), context.getSource().getClass());
modelMapper.createTypeMap(Base.class, Base.class).setConverter(baseBaseConverter);
Here 是关于该主题的更详细的 post。
我有以下 class 层次结构:
public abstract class Base {
protected Boolean baseBoolean;
}
public class A extends Base {
private BigDecimal amount;
}
并尝试将 DTO 映射到实体
public class DTO {
private Base details;
}
public class Entity {
private Base details;
}
并配图如下:
public static void main(String[] args) {
ModelMapper modelMapper = new ModelMapper();
modelMapper.getConfiguration().setDeepCopyEnabled(true);
A a = new A();
a.setAmount(BigDecimal.ONE);
a.setBaseBoolean(true);
DTO request = DTO.builder().base(a).build();
Entity entity = modelMapper.map(request, Entity.class);
System.out.println(entity);
}
我在详细信息字段中收到带有 A 或 B 的 DTO,这是用调试器检查的。但是模型映射器抛出
Failed to instantiate instance of destination org.package.Base. Ensure that org.package.Base has a non-private no-argument constructor.
我尝试使用显式提供程序(未用于此映射):
modelMapper.typeMap(A.class, Base.class).setProvider(new Provider<Base>() {
@Override
public Base get(ProvisionRequest<Base> r) {
return new A();
}
});
我也试过像这样实现自定义转换器(也没有执行):
modelMapper.typeMap(A.class, Base.class).setConverter(new Converter<A, Base>() {
@Override
public Base convert(MappingContext<A, Base> mappingContext) {
return modelMapper.map(mappingContext.getSource(), A.class);
}
});
modelmapper 似乎不将此类型映射用于字段,仅用于层次结构的根。 在这种情况下如何映射 class 层次结构?
如您所见,启用深层复制时会出现问题:modelMapper.getConfiguration().setDeepCopyEnabled(true)
。
一个解决方案是定义一个 Converter<Base, Base>
如下:
ModelMapper modelMapper = new ModelMapper();
modelMapper.getConfiguration().setDeepCopyEnabled(true); // this triggers the problem
// the converter resolves it
Converter<Base, Base> baseBaseConverter = context ->
modelMapper.map(context.getSource(), context.getSource().getClass());
modelMapper.createTypeMap(Base.class, Base.class).setConverter(baseBaseConverter);
Here 是关于该主题的更详细的 post。