Bug 515549

Description Yongkang Guo 2017-04-21 03:00:32 EDT

Created attachment 267896 [details]
project-to-reproduce-issue

Occasionally I find this issue. Where standard Java compiler says "wrong", the eclipse JDT says "OK".(Intellij IDEA also says "wrong" for your reference)
There're two ways to reproduce the issue:

Approach A:
1) Download the attached ZIP file and UNZIP.
2) Import the maven project into your workspace.
3) Right click the program 'AmbiguousMethodCallShowcase.java' and run as Java program.
At this point, you will see one line of output "Program is correct"
4) Now open command line prompt and 'cd' to the source directory.
5) Run command 'javac AmbiguousMethodCallShowcase.java'
At this point, you will see the java compiler gives error:

AmbiguousMethodCallShowcase.java:46: error: reference to findOne is ambiguous
        repo.findOne(1L);
            ^
  both method findOne(Long) in MyBaseEntityRepository and method findOne(ID) in CrudRepository match
  where T#1,ID,T#2 are type-variables:
    T#1 extends BaseEntity declared in interface MyBaseEntityRepository
    ID extends Serializable declared in interface CrudRepository
    T#2 extends Object declared in interface CrudRepository
1 error

Approach B:
1) Get the source code from https://github.com/guogin/problemapp
2) Import into eclipse as a maven project
3) Right click the program com.myapp.ProblemApplication and run as Java program (no need to install Spring boot plugins)
At this point, you will see the program is launched.
4) However if you go to command line and execute 'mvn clean package', you will see compilation error on ReportController.
The error says, reference to method 'findOne' is ambiguous, just like the approach A.

Best Regards,
Guo, Yongkang