This PR support a -k, --keep options like tar that allows jar to avoid override existing files.
------------- Commit messages: - Add simple test - Support legacy mode - 8335912: Add an operation mode to the jar command when extracting to not overwriting existing files Changes: https://git.openjdk.org/jdk/pull/21141/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21141&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8335912 Stats: 275 lines in 4 files changed: 274 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/21141.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21141/head:pull/21141 PR: https://git.openjdk.org/jdk/pull/21141
