Is there a Lombok annotation to get all fields of an object of a class as an Object array?

I have a class which represents the primary key (which is a composite one) of a database table.

@Value
public class ItemPrimaryKey {
    String compositeKeyColumnA;
    String compositeKeyColumnB;
    String compositeKeyColumnC;
    String compositeKeyColumnD;
}

When I want to read a row from the table by primary key, I should do the following:

jdbcTemplate.query(
    READ_ITEM_BY_PK_QUERY,
    new BeanPropertyRowMapper<>(Item.class),
    itemPrimaryKey.getCompositeKeyColumnA(),
    itemPrimaryKey.getCompositeKeyColumnB(),
    itemPrimaryKey.getCompositeKeyColumnC(),
    itemPrimaryKey.getCompositeKeyColumnD());

However, because the query method of JdbcTemplate takes Object... as its last parameter, I can do the following:

public class ItemPrimaryKey {
    // ...
    public Object[] getForVarArgs() {
        return new Object[] { compositeKeyColumnA, compositeKeyColumnB, compositeKeyColumnC, compositeKeyColumnD };
    }
}

jdbcTemplate.query(
    READ_ITEM_BY_PK_QUERY,
    new BeanPropertyRowMapper<>(Item.class),
    itemPrimaryKey.getForVarArgs());

Since I have the above situation for multiple classes/DB tables, I would like to achieve it with a Lombok annotation, if possible. Is there one that does this?

I have looked through Lombok's documentation, and googled, but I found no such thing. However, maybe there is a configuration for an existing annotation that could still achieve this?

I have adapted trandafir-emanuel's answer to the simplest possible solution I could think of. Classes only need to extend this abstract class, and they'll have toVarArgs() working out of the box (previously called getForVarArgs() - I had to rename it to something not starting with get, because otherwise Jackson tried to use the method during serialization).

Also, the order of definition of the fields is respected, which is clearly important in this case.

import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.LinkedHashMap;
import java.util.Map;

abstract class VarArgsConvertible {
    private Object[] thisAsVarArgs = null;

    public Object[] toVarArgs() {
        if (thisAsVarArgs == null) {
            Map<?, ?> thisAsMap = new ObjectMapper().convertValue(this, LinkedHashMap.class);
            thisAsVarArgs = thisAsMap.values().toArray();
        }

        return thisAsVarArgs;
    }
}

I am not aware of solutions with lombok, but there are alternatives.

Though it might not be a beautiful solutiuon, you can invoke the getter-methods from your class through reflection:

        Object[] objects = Arrays.stream(ItemPrimaryKey.class.getMethods())
                .filter(method -> Pattern.compile("getCompositeKeyColumn.").matcher(method.getName()).matches())
                .sorted(Comparator.comparing(Method::getName))
                .map(method -> {
                    try {
                        return method.invoke(itemPrimaryKey);
                    } catch (Exception e) {
                        throw new RuntimeException(e);
                    }
                })
                .toArray(Object[]::new);

Note that the order here is determined by sorting on the getter-name, which works with your specific example, but not generally. Also, the pattern might need adjustments if other fields in the class is needed.

However, at this point, you might be better off by creating an instance method in your class which returns the fields in an array.

you won't be able to do it with Lombok. If you are looking for alternatives, one way would be to convert the object to a hashmap using jackson, and then get all the keys:

private static String[] getFieldNames(Object obj) {
	Map<String, Object> map = new ObjectMapper().convertValue(obj, Map.class);
	return map.keySet().toArray();
}

though, I would rather manually enter the field names in the query, if it is not something that can dynamically change.