[OAK-7457] "Covariant return type change detected" warnings with java10

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.18.0
• Component/s: documentmk, segment-tar
• Epic Link: Oak should compile & test on Java 10
• Assignee: Marcel Reutegger
• Reporter: Julian Reschke
• Created: 27/Apr/18 07:15
• Updated: 30/Sep/19 07:35
• Resolved: 22/Aug/19 15:28

Description

We have quite a few warnings of type "Covariant return type change detected":

[INFO] C:\projects\apache\oak\trunk\oak-store-document\src\main\java\org\apache\jackrabbit\oak\plugins\document\persistentCache\broadcast\TCPBroadcaster.java:327: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.flip() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.flip()
[INFO] C:\projects\apache\oak\trunk\oak-store-document\src\main\java\org\apache\jackrabbit\oak\plugins\document\persistentCache\broadcast\UDPBroadcaster.java:135: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.limit(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.limit(int)
[INFO] C:\projects\apache\oak\trunk\oak-store-document\src\main\java\org\apache\jackrabbit\oak\plugins\document\persistentCache\broadcast\UDPBroadcaster.java:138: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-store-document\src\main\java\org\apache\jackrabbit\oak\plugins\document\persistentCache\broadcast\TCPBroadcaster.java:226: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-store-document\src\main\java\org\apache\jackrabbit\oak\plugins\document\persistentCache\broadcast\InMemoryBroadcaster.java:35: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-store-document\src\main\java\org\apache\jackrabbit\oak\plugins\document\persistentCache\PersistentCache.java:519: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.limit(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.limit(int)
[INFO] C:\projects\apache\oak\trunk\oak-store-document\src\main\java\org\apache\jackrabbit\oak\plugins\document\persistentCache\PersistentCache.java:522: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-store-document\src\main\java\org\apache\jackrabbit\oak\plugins\document\persistentCache\PersistentCache.java:535: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\data\SegmentDataV12.java:196: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\data\SegmentDataV12.java:197: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.limit(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.limit(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\data\SegmentDataUtils.java:57: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\data\SegmentDataUtils.java:58: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.limit(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.limit(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\index\IndexWriter.java:110: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\index\IndexLoaderV1.java:62: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.mark() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.mark()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\index\IndexLoaderV1.java:64: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.reset() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.reset()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\index\IndexLoaderV1.java:72: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.mark() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.mark()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\index\IndexLoaderV1.java:101: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.reset() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.reset()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\index\IndexLoaderV2.java:62: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.mark() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.mark()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\index\IndexLoaderV2.java:64: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.reset() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.reset()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\index\IndexLoaderV2.java:72: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.mark() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.mark()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\index\IndexLoaderV2.java:101: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.reset() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.reset()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\binaries\BinaryReferencesIndexLoader.java:71: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\binaries\BinaryReferencesIndexLoader.java:73: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.rewind() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.rewind()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\binaries\BinaryReferencesIndexLoaderV1.java:61: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.limit(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.limit(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\binaries\BinaryReferencesIndexLoaderV1.java:63: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\binaries\BinaryReferencesIndexLoaderV1.java:82: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.mark() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.mark()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\binaries\BinaryReferencesIndexLoaderV1.java:84: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.reset() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.reset()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\binaries\BinaryReferencesIndexLoaderV2.java:61: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.limit(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.limit(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\binaries\BinaryReferencesIndexLoaderV2.java:63: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\binaries\BinaryReferencesIndexLoaderV2.java:82: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.mark() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.mark()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\binaries\BinaryReferencesIndexLoaderV2.java:84: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.reset() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.reset()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\GraphLoader.java:78: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.mark() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.mark()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\GraphLoader.java:80: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.reset() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.reset()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\SegmentTarWriter.java:142: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.rewind() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.rewind()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\FileAccess.java:72: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\FileAccess.java:73: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.limit(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.limit(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\tar\SegmentTarManager.java:209: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\file\FileStore.java:489: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.rewind() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.rewind()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\memory\MemoryStore.java:118: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.rewind() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.rewind()
[INFO] C:\projects\apache\oak\trunk\oak-segment-tar\src\main\java\org\apache\jackrabbit\oak\segment\SegmentStream.java:156: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.position(int) has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.position(int)
[INFO] C:\projects\apache\oak\trunk\oak-segment-azure\src\main\java\org\apache\jackrabbit\oak\segment\azure\AzureUtilities.java:69: Covariant return type change detected: java.nio.Buffer java.nio.ByteBuffer.rewind() has been changed to java.nio.ByteBuffer java.nio.ByteBuffer.rewind()

I believe these will cause problems if we compile with java 10 but run on an earlier VM.

See also https://jira.mongodb.org/browse/JAVA-2559

Issue Links

• requires: OAK-8555 Move ByteBuffer wrapper to oak-commons project

Sub-Tasks

• Fix covariant return type changes in ByteBuffer: Closed