Add error catching in Key.Activate

Author: artemlos

src/main/java/io/cryptolens/methods/Key.java

@@ -41,6 +41,30 @@ public class Key {
      * @return A LicenseKey object if success and null otherwise.
      */
     public static LicenseKey Activate (String token, String RSAPubKey, ActivateModel model) {
+        return Activate(token, RSAPubKey, model,null);
+    }
+
+    /**
+     * Calls the Activate method (https://app.cryptolens.io/docs/api/v3/Activate).
+     * <p>This method allows you to retrieve the error message from the Web API.</p>
+     * <p>
+     *     To retrieve the error message, you need to initialize an APIError object and pass it in into the
+     *     "error" parameter. For example,
+     * </p>
+     * <code>
+     *     APIError error = new APIError();<br>
+     *     LicenseKey license = Key.Activate(auth, RSAPubKey, new ActivateModel(3349, "ICVLD-VVSZR-ZTICT-YKGXL", Helpers.GetMachineCode()), error);<br>
+     *     System.out.println(error.Message);
+     * </code>
+     * @param token The access token with 'Activate' permission.
+     * @param RSAPubKey Your RSA Public Key, which can be found at https://app.cryptolens.io/docs/api/v3/QuickStart.
+     * @param model Method parameters.
+     * @param error The error object whose Message field will be populated if an error has occurred. Please initialize
+     *              this parameter, i.e. define <code>APIError error = new APIError();</code> and then pass
+     *              <code>error</code> into this parameter.
+     * @return A LicenseKey object if success and null otherwise.
+     */
+    public static LicenseKey Activate (String token, String RSAPubKey, ActivateModel model, APIError error) {
 
         Map<String,String> extraParams = new HashMap<>();
 
@@ -53,6 +77,9 @@ public static LicenseKey Activate (String token, String RSAPubKey, ActivateModel
 
         if(result == null || result.result == 1) {
             if(result != null) {
+                if (error != null) {
+                    error.Message = result.message;
+                }
                 System.err.println("The server returned an error: " + result.message);
             } else {
                 System.err.println("The server returned an error.");

src/main/java/io/cryptolens/models/APIError.java

@@ -0,0 +1,14 @@
+package io.cryptolens.models;
+
+/**
+ * Used to store the error message obtained from the Web API.
+ */
+public class APIError {
+    public String Message;
+
+    public APIError() { Message = ""; }
+
+    public APIError(String message) {
+        Message = message;
+    }
+}

src/test/java/io/cryptolens/KeyTest.java

@@ -2,6 +2,7 @@
 
 import io.cryptolens.methods.Helpers;
 import io.cryptolens.methods.Key;
+import io.cryptolens.models.APIError;
 import io.cryptolens.models.ActivateModel;
 import io.cryptolens.models.DeactivateModel;
 import io.cryptolens.models.LicenseKey;
@@ -41,10 +42,13 @@ public void testApp() throws Exception {
         String RSAPubKey = "<RSAKeyValue><Modulus>sGbvxwdlDbqFXOMlVUnAF5ew0t0WpPW7rFpI5jHQOFkht/326dvh7t74RYeMpjy357NljouhpTLA3a6idnn4j6c3jmPWBkjZndGsPL4Bqm+fwE48nKpGPjkj4q/yzT4tHXBTyvaBjA8bVoCTnu+LiC4XEaLZRThGzIn5KQXKCigg6tQRy0GXE13XYFVz/x1mjFbT9/7dS8p85n8BuwlY5JvuBIQkKhuCNFfrUxBWyu87CFnXWjIupCD2VO/GbxaCvzrRjLZjAngLCMtZbYBALksqGPgTUN7ZM24XbPWyLtKPaXF2i4XRR9u6eTj5BfnLbKAU5PIVfjIS+vNYYogteQ==</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>";
         String auth = "WyIyNjA5IiwiaWE5b0VFT3Q2eDlNR2FvbHBHK2VOYUZ4bzNjT3h5UkNrMCtiYnhPRSJd";
 
-        LicenseKey license = Key.Activate(auth, RSAPubKey, new ActivateModel(3349, "ICVLD-VVSZR-ZTICT-YKGXL", Helpers.GetMachineCode()));
+        APIError error = new APIError();
+
+        LicenseKey license = Key.Activate(auth, RSAPubKey, new ActivateModel(3349, "ICVLD-VVSZR-ZTICT-YKGXL", Helpers.GetMachineCode()), error);
 
         if (license == null || !Helpers.IsOnRightMachine(license)) {
             System.out.println("The license does not work.");
+            System.out.println("Error: " + error.Message);
         } else {
             System.out.println("The license is valid!");
             System.out.println("It will expire: " + license.Expires);