java-jackson-时间格式化-javaTimeModule

[ichengzi]

// JavaTimeModule 依赖
<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jsr310</artifactId>
</dependency>

@Slf4j
public final class JsonUtils {

    private static ObjectMapper objectMapper = new ObjectMapper();

    static {
        // 如果json字段比较多，而我们对象只需要部分字段，这时反序列化时会报错,如下配置可以在反序列化时忽略json中多余的字段了
        objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

        // java.util.date
        String strFormat = "yyyy-MM-dd HH:mm:ss";
        objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
        objectMapper.setDateFormat(new SimpleDateFormat(strFormat));

        // java.time.localDateTime
        JavaTimeModule javaTimeModule = new JavaTimeModule();
        DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern(strFormat);
        javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(dateTimeFormatter));
        javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(dateTimeFormatter));
        objectMapper.registerModule(javaTimeModule);
    }

    @SneakyThrows
    public static String toJson(Object obj) {
        if (obj == null) {
            return "";
        }
        try {
            return objectMapper.writeValueAsString(obj);
        } catch (Exception e) {
            log.error("to json error", e);
            return "";
        }
    }
}

---

// test
public class JsonUtilsTest {

    @Test
    public void toJson() {
        Map<String, Object> items = Maps.newLinkedHashMap();
        items.put("java.util.date", new Date());
        items.put("java.time.localDateTime", LocalDateTime.now());
        items.put("java.time.LocalDate", LocalDate.now());
        items.put("java.time.LocalTime", LocalTime.now());

        String s = JsonUtils.toJsonIndent(items);
        System.out.println(s);
        /*{
            "java.util.date" : "2021-01-05 13:53:26",
            "java.time.localDateTime" : "2021-01-05 13:53:26",
            "java.time.LocalDate" : "2021-01-05",
            "java.time.LocalTime" : "13:53:26.607"
        }*/
        assertTrue(items != null);
    }
}