如何使用MapStruct 1.2有条件地映射属性? [英] How can I map properties conditionally with MapStruct 1.2?
问题描述
MapStruct 1.2是否可以将具有特定值的源属性映射到目标中的特定不同值?
Is it possible with MapStruct 1.2 to map a source property with a specific value to a specific different value in the target?
我考虑这样的事情:
public abstract class JiraKpmMapper {
@Mappings({
@Mapping(source = "mySource.propA", target = "myTarget.propX")
})
@ValueMappings({
@ValueMapping(source = "ABC", target = "XYZ"),
@ValueMapping(source = "123", target = "789")
})
public abstract MyTarget source2Target(final MySource mySource);
}
因此,当MapStruct在映射期间看到mySource.propA具有值"ABC"时,myTarget.propX需要设置为值"XYZ",依此类推.
So that when MapStruct sees during the mapping that when mySource.propA has the value "ABC" myTarget.propX needs to be set to value "XYZ" and so forth.
更准确地说,我什至希望更详细地阐述一些内容:目标应该是一个类的避风港,必须将所得的目标值分为三个属性.例如,如果mySource.propA的值为"ABC",则目标myTarget的值应为"V01.123.456.AB".该值又应分为preValue,middleValue和endValue:
To be more precisely, I even want something more elaborated: The target should be a class haven three properties in which the resulting target value must be split into. For instance, if mySource.propA has the value "ABC" the target myTarget should get a value like "V01.123.456.AB". This value in turn shall be split up in a preValue, a middleValue and an endValue:
preValue ="V01"
preValue = "V01"
middleValue ="123.456"
middleValue = "123.456"
endValue ="AB"
endValue = "AB"
因此,没有包含完整结果字符串的属性.
whereby there's no property holding the complete result string.
这就是为什么我已经编写了一个自定义映射器,并告诉MyMapper通过以下方式使用它的原因
That's why I already wrote a custom mapper and I tell the MyMapper to use it via
@Mapper(componentModel = "spring", uses = MyCustomMapper.class)
到目前为止,该方法仍然有效,但是当souzrce随附"ABC"时,我无法告诉MyCustomMapper将"V01.123.456.AB"放入目标.
This works so far but I can't achieve it to tell the MyCustomMapper to put "V01.123.456.AB" into the target when the souzrce comes with "ABC".
推荐答案
使用MapStruct不能真正做到这一点. @ValueMapping
批注用于映射 Enum
.
You can't really do that with MapStruct. The @ValueMapping
annotation is for mapping of Enum
(s).
要实现所需的功能,您需要在 @BeforeMapping
或 @AfterMapping
中进行操作.
In order to achieve what you are looking for you would need to do that in @BeforeMapping
or @AfterMapping
.
例如,您可以执行以下操作:
For example you can do something like:
@Mapper
public interface JiraKpmMapper {
@BeforeMapping
default void beforeMapping(@MappingTarget MyTarget target, MySource source) {
if (source.getPropY().equals("ABC") {
target.setPropX("V01.123.456.AB");
}
}
@Mapping(target = "propX", ignore = true) // This is now mapped in beforeMapping
MyTarget source2Target(final MySource mySource);
}
您的自定义映射器应该具有一个 @AfterMapping
.将 propX
转换为类的位置.您甚至可以将其作为我编写的 @BeforeMapping
的一部分并直接创建您的类(或调用将从 String
转换为类的方法)
Your custom mapper then should have an @AfterMapping
. Where you would convert the propX
into your class. You can even do this as part of the @BeforeMapping
I wrote and directly create your class (or invoke the method that does the conversion from String
into a class)
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