content: package com.alibaba.fastjson2.time;
  
  import com.alibaba.fastjson2.JSON;
  import com.alibaba.fastjson2.JSONWriter;
  import com.alibaba.fastjson2.annotation.JSONField;
  import org.junit.jupiter.api.Test;
  
  import java.util.ArrayList;
  import java.util.Calendar;
  import java.util.Date;
  import java.util.List;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  
  public class DateTest3 {
      @Test
      public void test_list() {
          Bean bean = new Bean();
          bean.dates = new ArrayList<>();
          bean.dates.add(new Date(1644578127098L));
  
          String str = JSON.toJSONString(bean);
          assertEquals("{\"dates\":[\"022022\"]}", str);
  
          Bean bean1 = JSON.parseObject(str, Bean.class);
          assertEquals(1, bean1.dates.size());
          Calendar instance = Calendar.getInstance();
          instance.setTime(bean1.dates.get(0));
          assertEquals(2022, instance.get(Calendar.YEAR));
          assertEquals(1, instance.get(Calendar.MONTH));
      }
  
      @Test
      public void test_null() {
          Bean bean = new Bean();
          String str = JSON.toJSONString(bean, JSONWriter.Feature.WriteNulls);
          assertEquals("{\"dates\":null}", str);
      }
  
      @Test
      public void test_null1() {
          Bean1 bean = new Bean1();
          String str = JSON.toJSONString(bean, JSONWriter.Feature.WriteNulls);
          assertEquals("{\"dates\":null}", str);
      }
  
      public static class Bean {
          @JSONField(format = "MMyyyy")
          public List<Date> dates;
      }
  
      private static class Bean1 {
          @JSONField(format = "MMyyyy")
          public List<Date> dates;
      }
  }
  