doCheckAddress broken for http protocol, and has poor feedback

[jglick]

#56 seems to have broken form validation for http-protocol URLs. The message gave no details. Also after fixing this, there was no visual indication that a successful check had been run.

[jglick]

Not sure I have time for it now, but I noticed that the form validation does not check authn; https://jenkins/whoAmI/api/json?tree=name should return a 200 response if authentication is correct. This is possible but would require some refactoring to share code with doCheckAddress:

diff --git src/main/java/org/jenkinsci/plugins/ParameterizedRemoteTrigger/auth2/TokenAuth.java src/main/java/org/jenkinsci/plugins/ParameterizedRemoteTrigger/auth2/TokenAuth.java
index 1b265af..d176297 100644
--- src/main/java/org/jenkinsci/plugins/ParameterizedRemoteTrigger/auth2/TokenAuth.java
+++ src/main/java/org/jenkinsci/plugins/ParameterizedRemoteTrigger/auth2/TokenAuth.java
@@ -12,8 +12,11 @@ import org.kohsuke.stapler.DataBoundConstructor;
 import org.kohsuke.stapler.DataBoundSetter;
 
 import hudson.Extension;
+import hudson.RelativePath;
 import hudson.model.Item;
+import hudson.util.FormValidation;
 import hudson.util.Secret;
+import org.kohsuke.stapler.QueryParameter;
 
 public class TokenAuth extends Auth2 {
 
@@ -76,6 +79,10 @@ public class TokenAuth extends Auth2 {
         public String getDisplayName() {
             return "Token Authentication";
         }
+
+        public FormValidation doCheckApiToken(@RelativePath("..") @QueryParameter String address, @QueryParameter String userName, @QueryParameter String apiToken) {
+            return FormValidation.ok("Example: address=" + address + " userName=" + userName + " apiToken=" + apiToken);
+        }
     }
 
     @Override