The StringBuilder and StringBuffer classes are Appendable by virtue of from subclasses their non-public superclass AbstractStringBuilder.
It is slightly clearer to declare StringBuilder and StringBuffer to directly implement Appendable, as they already directly implement the CharSequence interface also implemented by their superclass. There are no other interfaces implemented by AbstractStringBuilder other than Appendable and CharSequence. Please also review the CSR https://bugs.openjdk.org/browse/JDK-8305408 ------------- Commit messages: - JDK-8304945: StringBuilder and StringBuffer should implement Appendable explicitly Changes: https://git.openjdk.org/jdk/pull/13278/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13278&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8304945 Stats: 4 lines in 2 files changed: 0 ins; 0 del; 4 mod Patch: https://git.openjdk.org/jdk/pull/13278.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/13278/head:pull/13278 PR: https://git.openjdk.org/jdk/pull/13278