SpringBoot - jackson 序列化配置,支持jdk8 時間類型和解決科學計數法

jdk8時間序列化配置

@Configuration
public class JacksonConfig {
    @Bean
    public ObjectMapper serializingObjectMapper() {
        JavaTimeModule javaTimeModule = new JavaTimeModule();
        /** 序列化配置,針對java8 時間 **/
        javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        javaTimeModule.addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
        javaTimeModule.addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern("HH:mm:ss")));

        /** 反序列化配置,針對java8 時間 **/
        javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        javaTimeModule.addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
        javaTimeModule.addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern("HH:mm:ss")));
        
        return Jackson2ObjectMapperBuilder.json().modules(javaTimeModule).build();
    }        
}

另個寫法,時間和double類型序列化配置

@Configuration
public class JacksonConfig {
    @Bean
    public ObjectMapper serializingObjectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();
        
        // 設置時區
        objectMapper.setTimeZone(TimeZone.getTimeZone("GMT+8"));
	// 設置時間格式
        objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));

        JavaTimeModule javaTimeModule = new JavaTimeModule();
        /** 序列化配置,針對java8 時間 **/
        javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        javaTimeModule.addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
        javaTimeModule.addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern("HH:mm:ss")));

        /** 反序列化配置,針對java8 時間 **/
        javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        javaTimeModule.addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
        javaTimeModule.addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern("HH:mm:ss")));
        
        /** 聲明自定義模塊,配置double類型序列化配置 **/
        SimpleModule module = new SimpleModule("DoubleSerializer", new Version(1, 0, 0, ""));
        // 注意Double和double需要分配配置
        module.addSerializer(Double.class, new DoubleSerializer());
        module.addSerializer(double.class, new DoubleSerializer());

        /** 注冊模塊 **/
        objectMapper
                .registerModule(javaTimeModule)
                .registerModule(module)
		.registerModule(new Jdk8Module())
		.registerModule(new ParameterNamesModule());
        return objectMapper;
    }        
}

public class DoubleSerializer extends JsonSerializer<Double> {

	@Override
	public void serialize(Double value, JsonGenerator gen, SerializerProvider serializers)
			throws IOException {
		BigDecimal d = new BigDecimal(value.toString());
		gen.writeNumber(d.stripTrailingZeros().toPlainString());
	}

	@Override
	public Class<Double> handledType() {
		return Double.class;
	}
}

關於解決double類型科學計數法的問題,還可以做如下配置,不需要自己寫DoubleSerializer

objectMapper.enable(JsonGenerator.Feature.WRITE_BIGDECIMAL_AS_PLAIN);

https://stackoverflow.com/questions/25945044/jackson-serializer-for-primitive-types