[JCLOUDS-1333] Cannot compile jclouds with Guava 21+

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.1.0
• Fix Version/s: 2.3.0
• Component/s: jclouds-core
• Labels: guava
• Assignee: Andrew Gaul
• Reporter: Andrew Gaul
• Created: 25/Aug/17 19:54
• Updated: 18/Dec/21 01:20
• Resolved: 24/Jun/20 23:12

Description

jclouds has compatibility with Guava 18-22 but we cannot compile using 21+ due to some kind of Guava vs Java 8 Function class type error:

/home/gaul/work/jclouds/core/src/main/java/org/jclouds/rest/internal/TransformerForRequest.java:102: error: method compose in interface java.util.function.Function<T,R> cannot be applied to given types;
         transformer = compose(Function.class.cast(wrappingTransformer), transformer);
                       ^
  required: java.util.function.Function<? super V,? extends HttpRequest>
  found:    com.google.common.base.Function,com.google.common.base.Function<HttpResponse,CAP#1>
  reason: cannot infer type-variable(s) V
    (actual and formal argument lists differ in length)
  where V,T,R are type-variables:
    V extends Object declared in method <V>compose(java.util.function.Function<? super V,? extends T>)
    T extends Object declared in interface java.util.function.Function
    R extends Object declared in interface java.util.function.Function
  where CAP#1 is a fresh type-variable:
    CAP#1 extends Object from capture of ?
/home/gaul/work/jclouds/core/src/main/java/org/jclouds/rest/internal/TransformerForRequest.java:189: error: method compose in interface java.util.function.Function<T,R> cannot be applied to given types;
            transformer = compose(new OnlyElementOrNull(), transformer);
                          ^
  required: java.util.function.Function<? super V,? extends HttpRequest>
  found:    OnlyElementOrNull,com.google.common.base.Function<HttpResponse,CAP#1>
  reason: cannot infer type-variable(s) V
    (actual and formal argument lists differ in length)
  where V,T,R are type-variables:
    V extends Object declared in method <V>compose(java.util.function.Function<? super V,? extends T>)
    T extends Object declared in interface java.util.function.Function
    R extends Object declared in interface java.util.function.Function
  where CAP#1 is a fresh type-variable:
    CAP#1 extends Object from capture of ?

This does not affect applications from using Guava 21-22 but does impact our compatibility testing. Note that you need to set maven.compile.source to 1.8 to test Guava 21+.

Issue Links

• duplicates: JCLOUDS-1413 Guava 22 compatibility - HostAndPort.getHostText() has been removed