[MSHADE-168] ManifestResourceTransformer manifestEntries map declares wrong generic type

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 2.2
• Flags: Patch
• Assignee: Unassigned
• Reporter: Stuart McCulloch
• Created: 08/Apr/14 06:47
• Updated: 02/Jun/15 14:35
• Resolved: 02/Jun/15 14:31

Description

The ManifestResourceTransformer class declares a map called manifestEntries with a signature of Map<String, Attributes>. This is incorrect because at runtime this map is actually only ever populated with String values. Furthermore the only place where these map values are used is:

https://github.com/apache/maven-plugins/blob/trunk/maven-shade-plugin/src/main/java/org/apache/maven/plugins/shade/resource/ManifestResourceTransformer.java#L106

and while the signature of Attributes.put accepts values of any type, the javadoc states that values are checked that they are Strings at runtime:

http://docs.oracle.com/javase/7/docs/api/java/util/jar/Attributes.html#put(java.lang.Object,%20java.lang.Object)

In fact it turns out that you can change the manifestEntries Map signature to use any type for the value without getting a compile error - and at runtime it's ignored by the code populating the configuration. I only happened to notice this discrepancy when investigating a related issue involving a stricter version of the plexus MapConverter that checks generic bounds when populating maps:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=429369

The correct signature of manifestEntries should be Map<String, String>

Issue Links

• is duplicated by: MSHADE-183 Getting "Error creating shaded jar: java.util.jar.Attributes cannot be cast to java.lang.String" error when using ManifestResourceTransformer with Maven 3.2.5
• relates to: MNG-5534 Update to Sisu 0.3.0M1 and Guice 3.2.3