一、问题重现
IDEA抛出异常如下:
Caused by: java.lang.NullPointerException: pattern
at java.base/java.util.Objects.requireNonNull(Objects.java:246)
at java.base/java.time.format.DateTimeFormatterBuilder.appendPattern(DateTimeFormatterBuilder.java:1707)
at java.base/java.time.format.DateTimeFormatter.ofPattern(DateTimeFormatter.java:564)
at com.common.core.config.JacksonConfig.getObjectMapper(JacksonConfig.java:47)
at com.