Springboot 全局日期时间格式处理

• 1. GET请求及POST表单请求(RequestParam和PathVariable参数):
• -- 配置Converter<String, T>转换器实现参数转换, 该转换器bean会注入到spring mvc的参数解析器中（ParameterConversionService）
• 2. POST-application/json请求(RequestBody参数)
• -- 配置ObjectMapper（这个玩意儿会注入到Jackson的HttpMessagConverter里面，即MappingJackson2HttpMessageConverter中）来实现Json格式数据的序列化和反序列化

@Configuration
public class DateHandlerConfig {

    /**
     * 默认日期时间格式
     */
    private static final String DEFAULT_DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";
    /**
     * 默认日期格式
     */
    private static final String DEFAULT_DATE_FORMAT = "yyyy-MM-dd";
    /**
     * 默认时间格式
     */
    private static final String DEFAULT_TIME_FORMAT = "HH:mm:ss";

    /**
     * Date转换器
     * 采用hutool的日期解析工具类Dateutil可以匹配任意格式日期字符串
     */
    @Bean
    public Converter<String, Date> dateConverter() {
        return new Converter<String, Date>() {
            @Override
            public Date convert(String source) {
                return DateUtil.parse(source.trim());
            }
        };
    }

    /**
     * LocalDate转换器
     */
    @Bean
    public Converter<String, LocalDate> localDateConverter() {
        return new Converter<String, LocalDate>() {
            @Override
            public LocalDate convert(String source) {
                return LocalDate.parse(source, DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));
            }
        };
    }

    /**
     * LocalTime转换器
     */
    @Bean
    public Converter<String, LocalTime> localTimeConverter() {
        return new Converter<String, LocalTime>() {
            @Override
            public LocalTime convert(String source) {
                return LocalTime.parse(source, DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));
            }
        };
    }

    /**
     * LocalDateTime转换器
     */
    @Bean
    public Converter<String, LocalDateTime> localDateTimeConverter() {
        return new Converter<String, LocalDateTime>() {
            @Override
            public LocalDateTime convert(String source) {
                return LocalDateTime.parse(source, DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));
            }
        };
    }

    /**
     * Json序列化和反序列化转换器
     */
    @Bean
    public ObjectMapper objectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();

        //java8日期 Local系列序列化和反序列化模块
        JavaTimeModule javaTimeModule = new JavaTimeModule();
        javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));
        javaTimeModule.addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));
        javaTimeModule.addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));
        javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));
        javaTimeModule.addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));
        javaTimeModule.addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));

        objectMapper.registerModule(new ParameterNamesModule()).registerModule(new Jdk8Module()).registerModule(javaTimeModule);

        objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
        objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);
        // 忽略json字符串中不识别的属性
        objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        // 忽略无法转换的对象
        objectMapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
        // PrettyPrinter 格式化输出
        objectMapper.configure(SerializationFeature.INDENT_OUTPUT, true);
        // NULL不参与序列化
        objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        // 指定时区
        objectMapper.setTimeZone(TimeZone.getTimeZone("GMT+8:00"));
        /**
         * Date日期类型字符串全局处理, 默认格式为：yyyy-MM-dd HH:mm:ss
         * 局部处理某个Date属性字段接收或返回日期格式yyyy-MM-dd, 可采用@JsonFormat(pattern = "yyyy-MM-dd", timezone="GMT+8")注解标注该属性
         */
        objectMapper.setDateFormat(new SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT));

        return objectMapper;
    }

}