All good things must come to an end, and for the 1.x line of Spring Boot that means we will need to cease maintenance twelve months from today, on Aug 1st 2019.
We will keep publishing occasional 1.5.x maintenance releases up until that point and will then end the branch.
Existing Spring Boot 1.x users should plan accordingly to ensure that they have upgraded to the latest 2.x version before that date. Please also note that Spring Boot 2.0 and above requires Java 8+, so if you’re running Java 6 or 7 you should also plan on upgrading your JDK.
For detailed instructions on what you’ll need to do to upgrade a Spring Boot 1.5 application to 2.0, check out the migration guide.