ObjectMapperTest.java

package entity;

import com.fasterxml.jackson.annotation.JsonValue;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.PropertyNamingStrategy;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.google.common.collect.ImmutableMap;
import lombok.AllArgsConstructor;
import lombok.Getter;

import java.util.Map;

/**
 * @author ono_takahiko
 * @since 16/02/29
 */
public class ObjectMapperTest {

	private static final MyEntity ENTITY1 =
			new MyEntity(MyEnum.TYPE1, "This is a 1st sample entity.",
					ImmutableMap.of(MyEnum.TYPE1, "type1"));
	private static final MyEntity ENTITY2 =
			new MyEntity(MyEnum.TYPE2, "This is a 2nd sample entity.",
					ImmutableMap.of(MyEnum.TYPE2, "type2"));

	private ObjectMapper mapper;

	public ObjectMapperTest(ObjectMapper mapper) {
		this.mapper = mapper;
	}

	public void exec() throws JsonProcessingException {
		System.out.println(mapper.writeValueAsString(ENTITY1));
		System.out.println(mapper.writeValueAsString(ENTITY2));
		System.out.println("----");
	}

	public static void main(String... args) throws Exception {
		ObjectMapper mapper1 = new ObjectMapper();

		ObjectMapper mapper2 = new ObjectMapper();
		mapper2.configure(SerializationFeature.WRITE_ENUMS_USING_TO_STRING, true);
		mapper2.setPropertyNamingStrategy(
				PropertyNamingStrategy.CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES);

		ObjectMapper mapper3 = new ObjectMapper();
		mapper3.configure(SerializationFeature.WRITE_ENUMS_USING_INDEX, true);
		mapper3.setPropertyNamingStrategy(PropertyNamingStrategy.PASCAL_CASE_TO_CAMEL_CASE);

		new ObjectMapperTest(mapper1).exec();
		new ObjectMapperTest(mapper2).exec();
		new ObjectMapperTest(mapper3).exec();
	}

	@AllArgsConstructor
	@Getter
	public static class MyEntity {

		private MyEnum type;

		private String complexNameValue;

		private Map<MyEnum, String> enumIndexedMap;

	}

	public static enum MyEnum {

		TYPE1("type1"),

		TYPE2("type2")
		;

		private String code;

		private MyEnum(String code) {
			this.code = code;
		}

		@JsonValue
		public String getCode() {
			return code;
		}
	}

}

/*
{"type":"type1","complexNameValue":"This is a 1st sample entity.","enumIndexedMap":{"TYPE1":"type1"}}
{"type":"type2","complexNameValue":"This is a 2nd sample entity.","enumIndexedMap":{"TYPE2":"type2"}}
----
{"type":"type1","complex_name_value":"This is a 1st sample entity.","enum_indexed_map":{"TYPE1":"type1"}}
{"type":"type2","complex_name_value":"This is a 2nd sample entity.","enum_indexed_map":{"TYPE2":"type2"}}
----
{"Type":"type1","ComplexNameValue":"This is a 1st sample entity.","EnumIndexedMap":{"TYPE1":"type1"}}
{"Type":"type2","ComplexNameValue":"This is a 2nd sample entity.","EnumIndexedMap":{"TYPE2":"type2"}}
----
*/

    <dependencies>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.3.3</version>
        </dependency>

        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>19.0</version>
        </dependency>

        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.4</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.6</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>