How to Map List<String> from List<Object> Using MapStruct

How do I map a List<String> from a List<Object> using MapStruct?

public interface MyMapper {
    List<String> map(List<Object> objects);
}

MapStruct is a code generator that simplifies the implementation of mappings between Java bean types based on a convention-over-configuration approach. This makes it easy to convert collections, such as converting a List<Object> to a List<String>.

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.factory.Mappers;

@Mapper
public interface ObjectToStringMapper {
    ObjectToStringMapper INSTANCE = Mappers.getMapper(ObjectToStringMapper.class);

    List<String> map(List<Object> objects);

    default String mapObjectToString(Object obj) {
        return obj.toString(); // Replace with your logic for getting string value
    }
}

Causes

• The source list contains objects of varying types, requiring custom mapping to extract specific string attributes.
• MapStruct may need specific mapping configurations for the properties being converted.

Solutions

• Define a mapping method in the mapper interface to handle the conversion from List<Object> to List<String>.
• Use a custom mapping strategy to specify how to extract the string values from the object instances.

Mistake: Not configuring the correct property mappings in MapStruct.

Solution: Ensure that the properties of the source and target types are correctly set and use appropriate default methods.

Mistake: Forgetting to include the MapStruct dependency in the project.

Solution: Add the MapStruct dependencies to your build.gradle or pom.xml file.