content: package com.itheima.reggie.common;
  
  import com.fasterxml.jackson.databind.DeserializationFeature;
  import com.fasterxml.jackson.databind.ObjectMapper;
  import com.fasterxml.jackson.databind.module.SimpleModule;
  import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
  import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
  import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
  import com.fasterxml.jackson.datatype.jsr310.deser.LocalTimeDeserializer;
  import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;
  import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
  import com.fasterxml.jackson.datatype.jsr310.ser.LocalTimeSerializer;
  import java.math.BigInteger;
  import java.time.LocalDate;
  import java.time.LocalDateTime;
  import java.time.LocalTime;
  import java.time.format.DateTimeFormatter;
  import static com.fasterxml.jackson.databind.DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES;
  
  /**
   * 对象映射器:基于jackson将Java对象转为json，或者将json转为Java对象
   * 将JSON解析为Java对象的过程称为 [从JSON反序列化Java对象]
   * 从Java对象生成JSON的过程称为 [序列化Java对象到JSON]
   */
  public class JacksonObjectMapper extends ObjectMapper {
  
      public static final String DEFAULT_DATE_FORMAT = "yyyy-MM-dd";
      public static final String DEFAULT_DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";
      public static final String DEFAULT_TIME_FORMAT = "HH:mm:ss";
  
      public JacksonObjectMapper() {
          super();
          //收到未知属性时不报异常
          this.configure(FAIL_ON_UNKNOWN_PROPERTIES, false);
  
          //反序列化时，属性不存在的兼容处理
          this.getDeserializationConfig().withoutFeatures(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
  
  
          SimpleModule simpleModule = new SimpleModule()
                  .addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)))
                  .addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)))
                  .addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)))
  
                  .addSerializer(BigInteger.class, ToStringSerializer.instance)
                  .addSerializer(Long.class, ToStringSerializer.instance)
                  .addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)))
                  .addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)))
                  .addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));
  
          //注册功能模块 例如，可以添加自定义序列化器和反序列化器
          this.registerModule(simpleModule);
      }
  }
  