LinkedResource.java

import com.fasterxml.jackson.annotation.JsonUnwrapped;
import org.springframework.expression.spel.standard.SpelExpressionParser;

import java.util.HashMap;
import java.util.Map;


@SuppressWarnings({"unused", "FieldCanBeLocal"})
public class LinkedResource<T> {

    private static final SpelExpressionParser SPEL_EXPRESSION_PARSER = new SpelExpressionParser();

    @JsonUnwrapped
    private final T payload;

    private Map<String, Map<String, String>> _links;

    public LinkedResource(T payload, String href) {
        this.payload = payload;
        this._links = gerarSelfHref(payload, href);
    }

    private HashMap<String, Map<String, String>> gerarSelfHref(T payload, String href) {
        HashMap<String, Map<String, String>> links = new HashMap<>();
        HashMap<String, String> self = new HashMap<>();
        self.put("href", SPEL_EXPRESSION_PARSER.parseExpression(href).getValue(payload, String.class));
        links.put("self", self);
        return links;
    }

    public Map<String, Map<String, String>> get_links() {
        return _links;
    }

}

LinkedResourceTest.java

import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;


class LinkedResourceTest {

    @Test
    @DisplayName("Serializacao do LinkedResource inclui link")
    void linkedResource() {
        @SuppressWarnings("unused")
        class ExemploC {
            private final String nome;
            private final int idade;
            private ExemploC(String nome, int idade) { this.nome = nome; this.idade = idade; }
            public String getNome() { return nome; }
            public int getIdade() { return idade; }
        }

        LinkedResource<ExemploC> linkedResource = new LinkedResource<>(new ExemploC("BobNelson", 47), "'http://example.com/'+nome+'/'+idade");

        TestUtils.assertEqualsJson("{\n" +
            "  \"nome\": \"BobNelson\",\n" +
            "  \"idade\": 47,\n" +
            "  \"_links\": {\n" +
            "    \"self\": {\n" +
            "      \"href\": \"http://example.com/BobNelson/47\"\n" +
            "    }\n" +
            "  }\n" +
            "}", linkedResource);
    }

}