resteasy: fix string comparison

[jmini]

I did just run bin/jaxrs-resteasy-eap-petstore-server.sh to update samples/server/petstore/jaxrs-resteasy/. And I got this result.

Some behavior has changed: The problem is that:

• PetApiServiceImpl
• StoreApiServiceImpl
• UserApiServiceImpl

Are removed.
And DefaultApiServiceImpl is created instead.

I guess this is just the grouping setting that has changed...

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If you build the project and run it at d5d8c35 the sample folder is up-to-date. Later a change was introduced that changes

This is an other proof that we need #80

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@jimschubert has a script to do a git bisect somewhere I need to investigate.

For the moment I did it manually and found that cc29417 is already broken...

[jmini]

I found the problem:

openapi-generator/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaResteasyEapServerCodegen.java

Line 129 in 10ac402

if (StringUtils.isEmpty("")) {

It was introduced with 9ecd358. I will fix it.

[wing328]

Oops.. sorry. It was my bad. Please help fix it.

I've reviewed other changes in that commit and look ok to me. Please also take a look when you have time.

[jmini]

@wing328: for me 18a2b9e is the only thing that is requested to fix 9ecd358. The rest of commit 9ecd358 looks good to me.