英文:
pass parameter to jpa converter
问题
我正试图编写一个通用的 Converter，以在代码中的多个类似情况下重复使用。我有一组子类，我想使用一个 Converter 来处理它们，因此我想要传递一些东西（类类型/某些参数/等等）到 Converter，以便能够定义：
public class GenericConverter implements AttributeConverter<MyGenericClass, Integer> {
.
.
.
public MyGenericClass convertToEntityAttribute(Integer arg0) {
// 根据属性/初始化方法/等等在这里返回特定的子类
}
并且在实体中：
@Convert(converter = GenericConverter.class /*在这里传递一些东西*/)
protected SubClass1 var1;
@Convert(converter = GenericConverter.class /*在这里传递一些东西*/)
protected SubClass2 var2;
@Convert(converter = GenericConverter.class, /*在这里传递一些东西*/)
protected SubClass3 var3;
这是否可行？
英文:
I am trying to write a generic Converter to be used in multiple similar cases in my code. I have a set of subclasses that I want to handle using only one Converter, so I want to pass something (class type / some parameter / etc) to the Converter to be able to define
public class GenericConverter implements AttributeConverter<MyGenericClass , Integer> {
.
.
.
public MyGenericClass convertToEntityAttribute(Integer arg0) {
// return a certain sub class here according to an attribute / an initialization method / etc
}
and in the entities:
@Convert( converter = GenericConverter.class \*pass something here\* )
protected SubClass1 var1;
@Convert( converter = GenericConverter.class \*pass something here\* )
protected SubClass2 var2;
@Convert( converter = GenericConverter.class, \*pass something here\* )
protected SubClass3 var3;
Is this doable by any means?
答案1
得分: 1
我想将一些东西（类类型 / 某些参数 / 等等）传递给转换器以便进行定义。
我唯一能想到的方法是将 GenericConverter 声明为抽象类，定义一个带有你想要修改的参数的构造函数：
public abstract GenericConverter {
protected GenericConverter(Class<?> type, String someParameter, Object etc){
....
}
}
然后创建子类并传递这些参数：
public class SubClass1Converter extends GenericConverter {
public SubClass1Converter(){
super(SubClass1.class, "someValue", ....);
}
}
然后你可以在 @Convert 中使用这些子类：
@Convert(converter = SubClass1Converter.class)
我没有看到其他好的选择，因为 AttributeConverter 接口不会将转换的 Field（AnnotatedElement）传递给你。因此，你无法创建自己的注解并查找这个注解。
英文:
> I want to pass something (class type / some parameter / etc) to the Converter to be able to define
The only way I see is to make the GenericConverter abstract, define a constructor with the parameters you would like to modify
public abstract GenericConverter {
protected GenericConverter(Class<?> type, String someParameter, Object etc){
....
}
}
create subclasses and pass that arguments.
public class SubClass1Converter extends GenericConverter {
public SubClass1Converter(){
super(SubClass1.class, "someValue", ....);
}
}
Then you can use the subclasses in the @Convert.
@Convert(converter = SubClass1Converter.class)
I don't see other good options since the AttributeConverter interface does not pass you the Field (AnnotatedElement) that is converted. Thus you can't create an own annotation and lookup this one.
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