How do I map an empty array in the source object?

[asmith2306]

If my source object has an empty array in it's hierarchy it doesn't get mapped (or is ignored maybe?). I created a program here to demonstrate: https://onecompiler.com/java/3yktwzjc3

The output is:

FooDTO before: FooDTO{name='My foo DTO', bar=BarDTO{name='My foo's bar', jars=[]}}

Foo before: Foo{name='My Foo', bar=Bar{name='null', jars=[Jar{name='Jar 1'}, Jar{name='Jar 2'}]}}

Foo after: Foo{name='My foo DTO', bar=Bar{name='My foo's bar', jars=[Jar{name='Jar 1'}, Jar{name='Jar 2'}]}}

You can see I map FooDTO -> Foo. The mapping for everything works e.g. the name fields, but the empty 'jars' array in the FooDTO's bar object doesn't get mapped.

Any ideas? Thanks

[devrishal]

You need to write convertors to get the mapping done and add the same in your modelmapper.

EG:

Converter<List<JarDTO>, List<Jar>> convertJarList= new AbstractConverter<List<JarDTO>, List<Jar>>() {
            protected List<Jar> convert(List<JarDTO> source) {
                return source.stream().map(identity -> {
                    Jar jar= new Jar();
                    jar.setName(identity.getName());
                    return jar;
                }).collect(Collectors.toList());
            }
        };
        modelMapper.addConverter(convertJarList);