18: Adapt according to needs of first actual implementation (CR)

Task-Url: #18

dariahsp-core/src/main/java/eu/dariah/de/dariahsp/web/controller/CommonLoginController.java

 package eu.dariah.de.dariahsp.web.controller;
 
 import java.util.Map;
+import java.util.Optional;
 
 import org.pac4j.core.client.Client;
 import org.pac4j.core.config.Config;
@@ -26,7 +27,19 @@ public class CommonLoginController {
 	@Autowired private SecurityConfig securityConfig;
     @Autowired private Config config;
     @Autowired private JEEContext jeeContext;
-	
+    
+    private final String loginView;
+    
+    
+    public CommonLoginController() {
+    	this.loginView = "login";
+    }
+    
+    public CommonLoginController(String loginView) {
+    	this.loginView = loginView;
+    }
+    
+    
 	/**
 	 * Present the local login form; override if the desired view is not 'login'
 	 * 
@@ -39,7 +52,7 @@ public class CommonLoginController {
         final FormClient formClient = (FormClient) config.getClients().findClient(securityConfig.getLocal().getAuthorizerName()).orElseThrow();    
         map.put("callbackUrl", formClient.getCallbackUrl());
         map.put("requestUrl", requestUrl);
-        return "login";
+        return loginView;
     }
 	
 	/**
@@ -66,13 +79,13 @@ public class CommonLoginController {
 	/**
 	 * Initiate a login based on a requested authentication client specified in terms of a client_name GET parameter
 	 * 
-	 * @param client_name name of the authentication client
+	 * @param client_name name of the authentication client, null selects default
 	 * @return redirection
 	 */
-	@RequestMapping("/loginClient")
+	@RequestMapping("/startLogin")
     @ResponseBody
     public String forceLogin() {
-		final String clientName = authInfoHelper.getRequestedClientName();
+		final String clientName = Optional.ofNullable(authInfoHelper.getRequestedClientName()).orElse(securityConfig.getEnabledClientNames().get(0));
         final Client<?> client = config.getClients().findClient(clientName).orElse(null);
         if (client==null) {
         	throw new AuthenticatorNotAvailable(clientName);