It was a dirty exception I faced few weeks back. I was trying to to consume a REST API call using postForEntity.
Unfortunately my ID variable was in primitive long instead of Long. I hit with the following error. I had been roaming around without a clue.
org.springframework.http.converter.HttpMessageNotWritableException: Could not write JSON: (was java.lang.NullPointerException)
I shot this soft white sand beach at Coney Island recently
One after another – This was a strange exception I received today. I am not sure if this is a bug of JPA or underlying MySQL.
SQL Error: 1467, SQLState: HY000
Failed to read auto-increment value from storage engine
Servlet.service() for servlet [dispatcherServlet] in context with path  threw exception [Request processing failed; nested exception is org.springframework.orm.jpa.JpaSystemException: could not execute statement; nested exception is org.hibernate.exception.GenericJDBCException: could not execute statement] with root cause
java.sql.SQLException: Failed to read auto-increment value from storage engine
I was pretty much surprised, what else!
Server version: 10.1.36-MariaDB
Spring Boot :: (v2.1.7.RELEASE)
I tried this.
ALTER TABLE `feed_item_info` AUTO_INCREMENT =1
It does not help me.
ALTER TABLE `feed_item_info` ORDER BY `index`
It throws the following warning.
Warning: #1105 ORDER BY ignored as there is a user-defined clustered index in the table ‘feed_item_info’
But it was working.
I shot this recently, at the seashore which borders Singapore and Malaysia
I am in mid of a crud operation. This exception hit me today, when I updated an entity with @ManyToOne(cascade = CascadeType.ALL) relationship.
org.hibernate.PersistentObjectException: detached entity passed to persist: org.grassfield.feed.entity.Feed
To solve this bidirectional consistency problem, I need to change CascadeType.ALL to CasecaseType.MERGE.
Recently I shot this pretty lady (or mighty gentleman?) at Coney Island. This has no relation with this post anyway.