Replace StringBuffer with StringBuilder in IoUtil and TemplateUtil

[rohanKanojia]

Description

Early classes of the Java API, such as Vector, Hashtable and StringBuffer, were synchronized to make them thread-safe. Unfortunately, synchronization has a big negative impact on performance, even when using these collections from a single thread.

We should use unsynchronized update these places to use StringBuilder instead:
https://github.com/eclipse/jkube/blob/b25157bcafb4a9b6b738a0fce018fc3803e6b78e/jkube-kit/common/src/main/java/org/eclipse/jkube/kit/common/util/IoUtil.java#L141

https://github.com/eclipse/jkube/blob/b25157bcafb4a9b6b738a0fce018fc3803e6b78e/jkube-kit/common/src/main/java/org/eclipse/jkube/kit/common/util/TemplateUtil.java#L28

How to manually test my changes

Kubernetes

If you don't have a real Kubernetes cluster available (most probably), you can use Minikube or Kind to test with a local cluster.

• Minikube get started guide
• Kind (Requires Docker) quick start

OpenShift

If you don't have a real OpenShift cluster available (most probably), you can use Red Hat's developer Sandbox for Red Hat OpenShift. The only requirement is to have a Red Hat account.

Once you have your Sandbox environment, you'll need to download the oc tool from the cluster console.
(Press the ? icon and from the context menu select Command line tools, you'll be redirected to https://$subdomain.openshiftapps.com/command-lines-tools where you'll be able to download the CLI for your platform)

[Ash-KODES]

i am ready to work on the issue

[Onyinye91-ctrl]

Hello @Ash-KODES Is this issue still available? if yes, i will love to work on it

[rohanKanojia]

@Onyinye91-ctrl : Hi, Could you please check if you can work on #854 instead?

[Onyinye91-ctrl]

@rohanKanojia Just checked it out. Can i go for it?

[rohanKanojia]

@Onyinye91-ctrl : Yes, Could you please add a comment on the issue so that I can assign it to you?

[Onyinye91-ctrl]

@rohanKanojia I have already done that

[rohanKanojia]

Sorry for not being clear, I meant to comment on #854 . I can only assign users participating in specific issue conversations.

[tejassinghsital]

@rohanKanojia Greetings Sir, Sir I am looking for some simple issues that I can work on as my first ever contribution to open source. I''ve been actively looking for some beginner level issues but almost all are assigned already to others. I am little confused now so can you please put me in right direction? Really looking for your reply...

[rohanKanojia]

@Ash-KODES : polite ping, Are you still working on this issue? If not, Is it okay if I assign this to @tejassinghsital ?

@tejassinghsital : Thanks for showing interest in contributing to our project. Let me create some more good first issues by the end of today.

[Hell4U]

Hey, @rohanKanojia I am new to contributing. Can I get some simple issue for my way to first ever contribution to open source ? Since most of the first-timers-only issue were solved when I was finding them.

[manusa]

Hey, @rohanKanojia I am new to contributing. Can I get some simple issue for my way to first ever contribution to open source ? Since most of the first-timers-only issue were solved when I was finding them.

https://github.com/eclipse/jkube/labels/first-timers-only

We tend to add new issues here every day, or when there are no more available.

[Ash-KODES]

@Ash-KODES : polite ping, Are you still working on this issue? If not, Is it okay if I assign this to @tejassinghsital ?

@tejassinghsital : Thanks for showing interest in contributing to our project. Let me create some more good first issues by the end of today.

yes go ahead

[Hell4U]

So, I am just curious do I have to down mention below to this particular jkube/jkube-kit/common/src/main/java/org/eclipse/jkube/kit/common/util/IoUtil.java file or all the files present in project.

- StringBuffer ret = new StringBuffer("["); 
+ StringBuffer answer = new StringBuffer(); 

[rohanKanojia]

This issue is only applicable to two files mentioned in issue description.

[Hell4U]

Thanks for clearing the doubt.

[ronnuriel]

is this issue still open ?