support configurable authMethod

Author: zzzming

java/src/main/java/io/kafkaesque/pulsar/client/auth/AuthFactory.java

@@ -9,7 +9,7 @@ public final class AuthFactory {
     private AuthFactory() {}
 
     /**
-     * Request JWT from autho and pass the JWT to pulsar broker.
+     * Request JWT from auth0 and pass the JWT to pulsar broker.
      * @param domain
      * @param clientId
      * @param clientSecret
@@ -20,4 +20,22 @@ public static Authentication auth0(String domain, String clientId, String client
         return new AuthenticationAuth0(Auth0JWT.create(domain, clientId, clientSecret, audience).generateAndCheck());
 
     }
+
+    /**
+     * Request JWT from auth0 with optional authMethod.
+     * @param domain
+     * @param clientId
+     * @param clientSecret
+     * @param audience
+     * @param authMethod
+     * @return
+     */
+    public static Authentication auth0(String domain, String clientId, String clientSecret, String audience, String authMethod) {
+        String token = Auth0JWT.create(domain, clientId, clientSecret, audience).generateAndCheck();
+
+        AuthenticationAuth0 auth0 = new AuthenticationAuth0(token);
+        auth0.setAuthMethodName(authMethod);
+        return auth0;
+    }
+
 }

java/src/main/java/io/kafkaesque/pulsar/client/auth/AuthMethod.java

@@ -0,0 +1,13 @@
+package io.kafkaesque.pulsar.client.auth;
+
+import java.util.Arrays;
+import java.util.List;
+
+public final class AuthMethod {
+
+    public final static String TOKEN = "token";
+
+    public final static String AUTH0 = "auth0";
+    
+    public final static List<String> supportedMethods = Arrays.asList(TOKEN, AUTH0);
+}

java/src/main/java/io/kafkaesque/pulsar/client/auth/AuthenticationAuth0.java

@@ -25,6 +25,8 @@ public class AuthenticationAuth0 implements Authentication, EncodedAuthenticatio
     private static final long serialVersionUID = 1L;
     private Supplier<String> tokenSupplier;
 
+    private String authMethod = AuthMethod.AUTH0;
+
     public AuthenticationAuth0(String token) {
         this(() -> token);
     }
@@ -40,7 +42,15 @@ public void close() throws IOException {
 
     @Override
     public String getAuthMethodName() {
-        return "auth0";
+        return authMethod;
+    }
+
+    public void setAuthMethodName(String name) {
+        if (AuthMethod.supportedMethods.contains(name)) {
+            authMethod = name;
+        } else {
+            throw new IllegalArgumentException("unsupport auth method " + name);
+        }
     }
 
     @Override