How to implement a specific type converter?

Question

I have a source class that defines string attributes as CharSequence (unfortunately).

So the following:

@Mapper(source="charSeq", target="str")

gives me:

Can't map property "java.lang.CharSequence charSeq" to "java.lang.String str". Consider to declare/implement a mapping method: "java.lang.String map(java.lang.CharSequence value)"

How can I implement this mapper method and make it available to all my mappers so that I do it once and for all?

The error message tells you exactly what you need to do. Just implement the method and you're all good. — jannis, May 26 '20 at 12:06
If the issue is with the conversion, you can have a look @ https://stackoverflow.com/questions/7707556/how-to-convert-charsequence-to-string — Lazycoder-007, May 26 '20 at 12:09
Does this answer your question? [How can I convert String to Map using MapStruct?](https://stackoverflow.com/questions/48492207/how-can-i-convert-string-to-map-using-mapstruct) — Eklavya, May 26 '20 at 12:16

jannis · Accepted Answer · 2020-05-26T21:15:58.463

Create a String-CharSequence mapper:

@Mapper
public interface CharSequenceMapper {
    default String map(CharSequence charSequence) {
        return charSequence.toString();
    }

    default CharSequence map(String string) {
        return string;
    }
}

And use it with your mapper:

@Mapper(uses = CharSequenceMapper.class)
public interface MyMapper {
    // some code
}

IMHO CharSequence-String conversion should be built into the framework. Consider filing a a feature request at https://github.com/mapstruct/mapstruct/issues.

How to implement a specific type converter?

1 Answers1