Merge pull request #228 from contentstack/fix/DX-3455-error-message-improve

reeshika-h · web-flow · commit 072eb9be3dc6 · 2025-10-28T12:52:18.000+05:30
Error messages updates
diff --git a/src/main/java/com/contentstack/sdk/AssetLibrary.java b/src/main/java/com/contentstack/sdk/AssetLibrary.java
@@ -179,7 +179,11 @@ public AssetLibrary addParam(@NotNull String paramKey, @NotNull Object paramValu
         if (isValidKey(paramKey) && isValidValue(paramValue)) {
             urlQueries.put(paramKey, paramValue);
         } else {
-            logger.warning("Invalid key or value");
+            if (!isValidKey(paramKey)) {
+                logger.warning(ErrorMessages.INVALID_PARAMETER_KEY);
+            } else {
+                logger.warning(ErrorMessages.INVALID_PARAMETER_VALUE);
+            }
         }
         return this;
     }
@@ -310,9 +314,10 @@ public void getResultObject(List<Object> objects, JSONObject jsonObject, boolean
 
         List<Asset> assets = new ArrayList<>();
 
-        // if (objects == null || objects.isEmpty()) {
-        //     System.out.println("Objects list is null or empty");
-        // }
+        if (objects == null || objects.isEmpty()) {
+            logger.warning(ErrorMessages.MISSING_ASSETS_LIST);
+            return;
+        }
 
         if (objects != null && !objects.isEmpty()) {
             for (Object object : objects) {
@@ -328,9 +333,9 @@ public void getResultObject(List<Object> objects, JSONObject jsonObject, boolean
                 assets.add(asset);
             }
         } 
-        // else {
-        // System.out.println("Object is not an instance of AssetModel");
-        // }
+        else {
+            logger.warning(ErrorMessages.INVALID_OBJECT_TYPE_ASSET_MODEL);
+        }
 
         if (callback != null) {
             callback.onRequestFinish(ResponseType.NETWORK, assets);
@@ -351,7 +356,11 @@ public AssetLibrary where(String key, String value) {
             queryParams.put(key,value);
             urlQueries.put("query", queryParams);
         } else {
-            throw new IllegalArgumentException("Invalid key or value");
+            if (!isValidKey(key)) {
+                throw new IllegalArgumentException(ErrorMessages.INVALID_PARAMETER_KEY);
+            } else {
+                throw new IllegalArgumentException(ErrorMessages.INVALID_PARAMETER_VALUE);
+            }
         }
         return this;
     }
diff --git a/src/main/java/com/contentstack/sdk/AssetsModel.java b/src/main/java/com/contentstack/sdk/AssetsModel.java
@@ -31,7 +31,7 @@ public AssetsModel(JSONObject response) {
             List<?> assetsList = (List<?>) rawAssets;
             listResponse = new JSONArray(assetsList); // Convert to JSONArray
         } else if (rawAssets != null) {
-            throw new IllegalArgumentException("Invalid type for 'assets' key: " + rawAssets.getClass().getName());
+            throw new IllegalArgumentException(ErrorMessages.INVALID_ASSETS_TYPE);
         }
         if (listResponse != null) {
             listResponse.forEach(model -> {
diff --git a/src/main/java/com/contentstack/sdk/CSBackgroundTask.java b/src/main/java/com/contentstack/sdk/CSBackgroundTask.java
@@ -93,7 +93,7 @@ protected void checkHeader(@NotNull Map<String, Object> headers) {
         final Logger logger = Logger.getLogger("CSBackgroundTask");
         if (headers.size() == 0) {
             try {
-                throw new IllegalAccessException("CSBackgroundTask Header Exception");
+                throw new IllegalAccessException(ErrorMessages.MISSING_REQUEST_HEADERS);
             } catch (IllegalAccessException e) {
                 logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
             }
diff --git a/src/main/java/com/contentstack/sdk/CSHttpConnection.java b/src/main/java/com/contentstack/sdk/CSHttpConnection.java
@@ -158,7 +158,7 @@ private String getParams(HashMap<String, Object> params) {
                     urlParams += urlParams.equals("?") ? key + "=" + value : "&" + key + "=" + value;
                 }
             } catch (Exception e1) {
-                logger.log(Level.SEVERE, e1.getLocalizedMessage(), e1);
+                logger.log(Level.SEVERE, ErrorMessages.URL_PARAMETER_ENCODING_FAILED, e1);
             }
         }
         return urlParams;
@@ -187,7 +187,7 @@ public void send() {
         try {
             getService(url);
         } catch (IOException | JSONException e) {
-            logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
+            logger.log(Level.SEVERE, ErrorMessages.URL_PARAMETER_ENCODING_FAILED, e);
         }
     }
 
@@ -238,7 +238,7 @@ private void getService(String requestUrl) throws IOException {
                     connectionRequest.onRequestFinished(CSHttpConnection.this);
                 } catch (JSONException e) {
                     // Handle non-JSON response
-                    setError("Invalid JSON response");
+                    setError(ErrorMessages.INVALID_JSON_RESPONSE);
                 }
             } else {
                 assert response.errorBody() != null;
diff --git a/src/main/java/com/contentstack/sdk/ContentType.java b/src/main/java/com/contentstack/sdk/ContentType.java
@@ -40,7 +40,7 @@ public class ContentType {
     public JSONObject contentTypeData;
 
     protected ContentType() throws IllegalAccessException {
-        throw new IllegalAccessException("Can Not Access Private Modifier");
+        throw new IllegalAccessException(ErrorMessages.DIRECT_INSTANTIATION_CONTENT_TYPE);
     }
 
     protected ContentType(String contentTypeUid) {
@@ -158,7 +158,7 @@ public void fetch(@NotNull JSONObject params, final ContentTypesCallback callbac
         }
         params.put("environment", headers.get("environment"));
         if (contentTypeUid == null || contentTypeUid.isEmpty()) {
-            throw new IllegalAccessException("contentTypeUid is required");
+            throw new IllegalAccessException(ErrorMessages.CONTENT_TYPE_UID_REQUIRED);
         }
         fetchContentTypes(urlString, params, headers, callback);
     }
diff --git a/src/main/java/com/contentstack/sdk/ContentTypesModel.java b/src/main/java/com/contentstack/sdk/ContentTypesModel.java
@@ -29,7 +29,7 @@ public void setJSON(JSONObject responseJSON) {
                 try {
                     this.response = new JSONObject((LinkedHashMap<?, ?>) responseJSON.get(ctKey));
                 } catch (Exception e) {
-                    System.err.println("Error processing 'content_type': " + e.getMessage());
+                    System.err.println(ErrorMessages.INVALID_CONTENT_TYPE_DATA + " Technical details: " + e.getMessage());
                 }
             }
             String ctListKey = "content_types";
@@ -44,14 +44,14 @@ public void setJSON(JSONObject responseJSON) {
                             JSONObject jsonModel = new JSONObject((LinkedHashMap<?, ?>) model);
                             objectList.add(jsonModel);
                         } else {
-                            System.err.println("Invalid type in 'content_types' list. Expected LinkedHashMap.");
+                            System.err.println(ErrorMessages.INVALID_CONTENT_TYPES_LIST);
                         }
                     });
                 }
                 this.response = new JSONArray(objectList);
                 this.responseJSONArray = new JSONArray(objectList);
             } catch (Exception e) {
-            System.err.println("Error processing 'content_types': " + e.getMessage());
+            System.err.println(ErrorMessages.INVALID_CONTENT_TYPE_DATA + " Technical details: " + e.getMessage());
         }
       }
     }
diff --git a/src/main/java/com/contentstack/sdk/Contentstack.java b/src/main/java/com/contentstack/sdk/Contentstack.java
@@ -19,7 +19,7 @@ public class Contentstack {
 
     // Modifier Protected
     protected Contentstack() throws IllegalAccessException {
-        throw new IllegalAccessException("Can Not Access Private Modifier");
+        throw new IllegalAccessException(ErrorMessages.DIRECT_INSTANTIATION_CONTENTSTACK);
     }
 
     /**
@@ -88,13 +88,13 @@ private static void validateCredentials(String stackApiKey, String deliveryToken
         Objects.requireNonNull(environment, "Environment can not be null");
 
         if (stackApiKey.isEmpty()) {
-            throw new IllegalAccessException("API Key can not be empty");
+            throw new IllegalAccessException(ErrorMessages.MISSING_API_KEY);
         }
         if (deliveryToken.isEmpty()) {
-            throw new IllegalAccessException("Delivery Token can not be empty");
+            throw new IllegalAccessException(ErrorMessages.MISSING_DELIVERY_TOKEN);
         }
         if (environment.isEmpty()) {
-            throw new IllegalAccessException("Environment can not be empty");
+            throw new IllegalAccessException(ErrorMessages.MISSING_ENVIRONMENT);
         }
     }
 
diff --git a/src/main/java/com/contentstack/sdk/EntriesModel.java b/src/main/java/com/contentstack/sdk/EntriesModel.java
@@ -33,7 +33,7 @@ protected EntriesModel(JSONObject responseJSON) {
             }
         } catch (Exception e) {
             Logger logger = Logger.getLogger(EntriesModel.class.getSimpleName());
-            logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
+            logger.log(Level.SEVERE, ErrorMessages.ENTRIES_PROCESSING_FAILED, e);
         }
 
     }
diff --git a/src/main/java/com/contentstack/sdk/Entry.java b/src/main/java/com/contentstack/sdk/Entry.java
@@ -45,7 +45,7 @@ public class Entry {
     protected String rteContent = null;
 
     protected Entry() throws IllegalAccessException {
-        throw new IllegalAccessException("Can Not Access Private Modifier");
+        throw new IllegalAccessException(ErrorMessages.DIRECT_INSTANTIATION_ENTRY);
     }
 
     protected Entry(String contentTypeName) {
@@ -503,7 +503,7 @@ public Calendar getDate(@NotNull String key) {
             String value = getString(key);
             return Constants.parseDate(value, null);
         } catch (Exception e) {
-            logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
+            logger.log(Level.SEVERE, ErrorMessages.INVALID_DATE_FORMAT, e);
         }
         return null;
     }
@@ -525,7 +525,7 @@ public Calendar getCreateAt() {
             String value = getString("created_at");
             return Constants.parseDate(value, null);
         } catch (Exception e) {
-            logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
+            logger.log(Level.SEVERE, ErrorMessages.INVALID_DATE_FORMAT, e);
         }
         return null;
     }
@@ -562,7 +562,7 @@ public Calendar getUpdateAt() {
             String value = getString("updated_at");
             return Constants.parseDate(value, null);
         } catch (Exception e) {
-            logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
+            logger.log(Level.SEVERE, ErrorMessages.INVALID_DATE_FORMAT, e);
         }
         return null;
     }
@@ -601,7 +601,7 @@ public Calendar getDeleteAt() {
             String value = getString("deleted_at");
             return Constants.parseDate(value, null);
         } catch (Exception e) {
-            logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
+            logger.log(Level.SEVERE, ErrorMessages.INVALID_DATE_FORMAT, e);
         }
         return null;
     }
@@ -764,7 +764,7 @@ public List<Entry> getAllEntries(String refKey, String refContentType) {
                         entryInstance = contentType.stackInstance.contentType(refContentType).entry();
                     } catch (Exception e) {
                         entryInstance = new Entry(refContentType);
-                        logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
+                        logger.log(Level.SEVERE, ErrorMessages.INVALID_DATE_FORMAT, e);
                     }
                     entryInstance.setUid(model.uid);
                     entryInstance.resultJson = model.jsonObject;
@@ -928,9 +928,9 @@ public Entry exceptWithReferenceUid(@NotNull List<String> fieldUid, @NotNull Str
     public void fetch(EntryResultCallBack callback) {
         if (uid.isEmpty()) { // throws IllegalAccessException if uid is Empty
             try {
-                throw new IllegalAccessException("Entry Uid is required");
+                throw new IllegalAccessException(ErrorMessages.ENTRY_UID_REQUIRED);
             } catch (IllegalAccessException e) {
-                logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
+                logger.log(Level.SEVERE, ErrorMessages.ENTRY_FETCH_FAILED, e);
             }
         }
         String urlString = "content_types/" + contentTypeUid + "/entries/" + uid;
diff --git a/src/main/java/com/contentstack/sdk/ErrorMessages.java b/src/main/java/com/contentstack/sdk/ErrorMessages.java
@@ -0,0 +1,76 @@
+package com.contentstack.sdk;
+
+/**
+ * Centralized error messages for the Contentstack SDK.
+ * This class contains all user-facing error messages to ensure consistency
+ * and make maintenance easier.
+ */
+public final class ErrorMessages {
+
+    // Prevent instantiation
+    private ErrorMessages() {
+        throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
+    }
+
+    // ========== AUTHENTICATION & ACCESS ERRORS ==========
+    
+    public static final String MISSING_API_KEY = "Missing API key. Provide a valid key from your Contentstack stack settings and try again.";
+    public static final String MISSING_DELIVERY_TOKEN = "Missing delivery token. Provide a valid token from your Contentstack stack settings and try again.";
+    public static final String MISSING_ENVIRONMENT = "Missing environment. Provide a valid environment name and try again.";
+    public static final String MISSING_REQUEST_HEADERS = "Missing request headers. Provide api_key, access_token, and environment, then try again.";
+    
+    // ========== DIRECT INSTANTIATION ERRORS ==========
+    
+    public static final String DIRECT_INSTANTIATION_STACK = "Direct instantiation of Stack is not allowed. Use Contentstack.stack() to create an instance.";
+    public static final String DIRECT_INSTANTIATION_CONTENTSTACK = "Direct instantiation of Stack is not allowed. Use Contentstack.stack() to create an instance.";
+    public static final String DIRECT_INSTANTIATION_CONTENT_TYPE = "Direct instantiation of ContentType is not allowed. Use Stack.contentType(uid) to create an instance.";
+    public static final String DIRECT_INSTANTIATION_ENTRY = "Direct instantiation of Entry is not allowed. Use ContentType.entry(uid) to create an instance.";
+    
+    // ========== REQUIRED FIELD ERRORS ==========
+    
+    public static final String CONTENT_TYPE_UID_REQUIRED = "Content type UID is required. Provide a valid UID and try again.";
+    public static final String ENTRY_UID_REQUIRED = "Missing entry UID. Provide a valid UID and try again.";
+    public static final String GLOBAL_FIELD_UID_REQUIRED = "Missing global field UID. Provide a valid UID and try again.";
+    
+    // ========== DATA VALIDATION ERRORS ==========
+    
+    public static final String INVALID_PARAMETER_KEY = "Invalid parameter key. Use only alphanumeric characters, underscores, and dots.";
+    public static final String INVALID_PARAMETER_VALUE = "Invalid parameter value. Remove unsupported characters and try again.";
+    public static final String INVALID_QUERY_URL = "Invalid query URL. Use a valid URL and try again.";
+    public static final String INVALID_DATE_FORMAT = "Invalid date format for field. Provide the date in ISO format and try again.";
+    
+    // ========== DATA TYPE ERRORS ==========
+    
+    public static final String INVALID_ASSETS_TYPE = "Invalid type for 'assets' key. Provide assets as a List or ArrayList and try again.";
+    public static final String INVALID_OBJECT_TYPE_ASSET_MODEL = "Invalid object type. Use an AssetModel object and try again.";
+    public static final String INVALID_CONTENT_TYPE_DATA = "Invalid content type data. Provide a LinkedHashMap structure and try again.";
+    public static final String INVALID_CONTENT_TYPES_LIST = "Invalid type in content types list. Use a LinkedHashMap and try again.";
+    public static final String INVALID_GLOBAL_FIELD_DATA = "Invalid global field data. Provide a LinkedHashMap structure and try again.";
+    public static final String INVALID_GLOBAL_FIELDS_LIST = "Invalid type in global fields list. Use a LinkedHashMap and try again.";
+    
+    // ========== MISSING DATA ERRORS ==========
+    
+    public static final String MISSING_ASSETS_LIST = "Missing assets list. Provide a valid list of assets and try again.";
+    public static final String MISSING_JSON_OBJECT_SYNC = "Missing JSON object for sync operation. Provide a valid JSON object with sync parameters and try again.";
+    
+    // ========== NETWORK & CONNECTION ERRORS ==========
+    
+    public static final String URL_PARAMETER_ENCODING_FAILED = "URL parameter encoding failed. Provide a valid key and value, then try again.";
+    public static final String LIVE_PREVIEW_URL_FAILED = "Failed to execute the Live Preview URL. Check your connection and try again.";
+    public static final String TAXONOMY_QUERY_FAILED = "Failed to execute taxonomy query. Check your network connection and verify taxonomy parameters.";
+    public static final String INVALID_JSON_RESPONSE = "Invalid JSON response. Check the server response format and try again.";
+    
+    // ========== CONFIGURATION ERRORS ==========
+    
+    public static final String MISSING_PREVIEW_TOKEN = "Missing preview token for rest-preview.contentstack.com. Set the preview token in your configuration to use Live Preview.";
+    public static final String LIVE_PREVIEW_NOT_ENABLED = "Live Preview is not enabled in the configuration. Enable it and try again.";
+    public static final String EMBEDDED_ITEMS_NOT_INCLUDED = "Embedded items are not included in the entry. Call includeEmbeddedItems() and try again.";
+    
+    // ========== OPERATION ERRORS ==========
+    
+    public static final String ENTRY_FETCH_FAILED = "Entry fetch operation failed due to missing UID. Provide a valid UID and try again.";
+    public static final String QUERY_EXECUTION_FAILED = "Query execution failed. Check the query and try again.";
+    public static final String ENTRIES_PROCESSING_FAILED = "Failed to process entries data. Check the entries format and try again.";
+    public static final String GROUP_DATE_PARSING_FAILED = "Failed to parse date from group field. Provide a valid date format and try again.";
+    public static final String QUERY_RESULT_PROCESSING_FAILED = "Failed to process query result data. Check the response format and try again.";
+}
diff --git a/src/main/java/com/contentstack/sdk/GlobalField.java b/src/main/java/com/contentstack/sdk/GlobalField.java
@@ -85,7 +85,7 @@ public GlobalField includeGlobalFieldSchema() {
     public void fetch(final GlobalFieldsCallback callback) throws IllegalAccessException {
         String urlString = "global_fields/" + globalFieldUid;
         if (globalFieldUid == null || globalFieldUid.isEmpty()) {
-            throw new IllegalAccessException("globalFieldUid is required");
+            throw new IllegalAccessException(ErrorMessages.GLOBAL_FIELD_UID_REQUIRED);
         }
         fetchGlobalFields(urlString, this.params, this.headers, callback);
     }
diff --git a/src/main/java/com/contentstack/sdk/GlobalFieldsModel.java b/src/main/java/com/contentstack/sdk/GlobalFieldsModel.java
@@ -21,7 +21,7 @@ public void setJSON(JSONObject responseJSON) {
                 try {
                     this.response = new JSONObject((LinkedHashMap<?, ?>) responseJSON.get(gfKey));
                 } catch (Exception e) {
-                    System.err.println("Error processing 'global_field': " + e.getMessage());
+                    System.err.println(ErrorMessages.INVALID_GLOBAL_FIELD_DATA + " Technical details: " + e.getMessage());
                 }
             }
             String gfListKey = "global_fields";
@@ -36,14 +36,14 @@ public void setJSON(JSONObject responseJSON) {
                                 JSONObject jsonModel = new JSONObject((LinkedHashMap<?, ?>) model);
                                 objectList.add(jsonModel);
                             } else {
-                                System.err.println("Invalid type in 'global_fields' list. Expected LinkedHashMap.");
+                                System.err.println(ErrorMessages.INVALID_GLOBAL_FIELDS_LIST);
                             }
                         });
                     }
                     this.response = new JSONArray(objectList);
                     this.responseJSONArray = new JSONArray(objectList);
                 } catch (Exception e) {
-                    System.err.println("Error processing 'global_fields': " + e.getMessage());
+                    System.err.println(ErrorMessages.INVALID_GLOBAL_FIELD_DATA + " Technical details: " + e.getMessage());
                 }
             }
         }
diff --git a/src/main/java/com/contentstack/sdk/Group.java b/src/main/java/com/contentstack/sdk/Group.java
@@ -291,7 +291,7 @@ public Calendar getDate(String key) {
             String value = getString(key);
             return Constants.parseDate(value, null);
         } catch (Exception e) {
-            logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
+            logger.log(Level.SEVERE, ErrorMessages.GROUP_DATE_PARSING_FAILED, e);
         }
         return null;
     }
diff --git a/src/main/java/com/contentstack/sdk/Query.java b/src/main/java/com/contentstack/sdk/Query.java
@@ -1235,7 +1235,7 @@ private void throwException(String queryName, String messageString, @Nullable Ex
         }
         errorHashMap.put("detail", messageString);
         assert e != null;
-        logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
+        logger.log(Level.SEVERE, ErrorMessages.QUERY_EXECUTION_FAILED, e);
     }
 
     protected void setQueryJson() {
diff --git a/src/main/java/com/contentstack/sdk/QueryResult.java b/src/main/java/com/contentstack/sdk/QueryResult.java
diff --git a/src/main/java/com/contentstack/sdk/Stack.java b/src/main/java/com/contentstack/sdk/Stack.java
diff --git a/src/main/java/com/contentstack/sdk/SyncStack.java b/src/main/java/com/contentstack/sdk/SyncStack.java

Original file line number	Diff line number	Diff line change
`@@ -31,7 +31,7 @@ public AssetsModel(JSONObject response) {`
`31`	`31`	`List<?> assetsList = (List<?>) rawAssets;`
`32`	`32`	`listResponse = new JSONArray(assetsList); // Convert to JSONArray`
`33`	`33`	`} else if (rawAssets != null) {`
`34`		`- throw new IllegalArgumentException("Invalid type for 'assets' key: " + rawAssets.getClass().getName());`
	`34`	`+ throw new IllegalArgumentException(ErrorMessages.INVALID_ASSETS_TYPE);`
`35`	`35`	`}`
`36`	`36`	`if (listResponse != null) {`
`37`	`37`	`listResponse.forEach(model -> {`
Original file line number	Diff line number	Diff line change
`@@ -93,7 +93,7 @@ protected void checkHeader(@NotNull Map<String, Object> headers) {`
`93`	`93`	`final Logger logger = Logger.getLogger("CSBackgroundTask");`
`94`	`94`	`if (headers.size() == 0) {`
`95`	`95`	`try {`
`96`		`- throw new IllegalAccessException("CSBackgroundTask Header Exception");`
	`96`	`+ throw new IllegalAccessException(ErrorMessages.MISSING_REQUEST_HEADERS);`
`97`	`97`	`} catch (IllegalAccessException e) {`
`98`	`98`	`logger.log(Level.SEVERE, e.getLocalizedMessage(), e);`
`99`	`99`	`}`
Original file line number	Diff line number	Diff line change
`@@ -158,7 +158,7 @@ private String getParams(HashMap<String, Object> params) {`
`158`	`158`	`urlParams += urlParams.equals("?") ? key + "=" + value : "&" + key + "=" + value;`
`159`	`159`	`}`
`160`	`160`	`} catch (Exception e1) {`
`161`		`- logger.log(Level.SEVERE, e1.getLocalizedMessage(), e1);`
	`161`	`+ logger.log(Level.SEVERE, ErrorMessages.URL_PARAMETER_ENCODING_FAILED, e1);`
`162`	`162`	`}`
`163`	`163`	`}`
`164`	`164`	`return urlParams;`
`@@ -187,7 +187,7 @@ public void send() {`
`187`	`187`	`try {`
`188`	`188`	`getService(url);`
`189`	`189`	`} catch (IOException \| JSONException e) {`
`190`		`- logger.log(Level.SEVERE, e.getLocalizedMessage(), e);`
	`190`	`+ logger.log(Level.SEVERE, ErrorMessages.URL_PARAMETER_ENCODING_FAILED, e);`
`191`	`191`	`}`
`192`	`192`	`}`
`193`	`193`
`@@ -238,7 +238,7 @@ private void getService(String requestUrl) throws IOException {`
`238`	`238`	`connectionRequest.onRequestFinished(CSHttpConnection.this);`
`239`	`239`	`} catch (JSONException e) {`
`240`	`240`	`// Handle non-JSON response`
`241`		`- setError("Invalid JSON response");`
	`241`	`+ setError(ErrorMessages.INVALID_JSON_RESPONSE);`
`242`	`242`	`}`
`243`	`243`	`} else {`
`244`	`244`	`assert response.errorBody() != null;`
Original file line number	Diff line number	Diff line change
`@@ -40,7 +40,7 @@ public class ContentType {`
`40`	`40`	`public JSONObject contentTypeData;`
`41`	`41`
`42`	`42`	`protected ContentType() throws IllegalAccessException {`
`43`		`- throw new IllegalAccessException("Can Not Access Private Modifier");`
	`43`	`+ throw new IllegalAccessException(ErrorMessages.DIRECT_INSTANTIATION_CONTENT_TYPE);`
`44`	`44`	`}`
`45`	`45`
`46`	`46`	`protected ContentType(String contentTypeUid) {`
`@@ -158,7 +158,7 @@ public void fetch(@NotNull JSONObject params, final ContentTypesCallback callbac`
`158`	`158`	`}`
`159`	`159`	`params.put("environment", headers.get("environment"));`
`160`	`160`	`if (contentTypeUid == null \|\| contentTypeUid.isEmpty()) {`
`161`		`- throw new IllegalAccessException("contentTypeUid is required");`
	`161`	`+ throw new IllegalAccessException(ErrorMessages.CONTENT_TYPE_UID_REQUIRED);`
`162`	`162`	`}`
`163`	`163`	`fetchContentTypes(urlString, params, headers, callback);`
`164`	`164`	`}`
Original file line number	Diff line number	Diff line change
`@@ -29,7 +29,7 @@ public void setJSON(JSONObject responseJSON) {`
`29`	`29`	`try {`
`30`	`30`	`this.response = new JSONObject((LinkedHashMap<?, ?>) responseJSON.get(ctKey));`
`31`	`31`	`} catch (Exception e) {`
`32`		`- System.err.println("Error processing 'content_type': " + e.getMessage());`
	`32`	`+ System.err.println(ErrorMessages.INVALID_CONTENT_TYPE_DATA + " Technical details: " + e.getMessage());`
`33`	`33`	`}`
`34`	`34`	`}`
`35`	`35`	`String ctListKey = "content_types";`
`@@ -44,14 +44,14 @@ public void setJSON(JSONObject responseJSON) {`
`44`	`44`	`JSONObject jsonModel = new JSONObject((LinkedHashMap<?, ?>) model);`
`45`	`45`	`objectList.add(jsonModel);`
`46`	`46`	`} else {`
`47`		`- System.err.println("Invalid type in 'content_types' list. Expected LinkedHashMap.");`
	`47`	`+ System.err.println(ErrorMessages.INVALID_CONTENT_TYPES_LIST);`
`48`	`48`	`}`
`49`	`49`	`});`
`50`	`50`	`}`
`51`	`51`	`this.response = new JSONArray(objectList);`
`52`	`52`	`this.responseJSONArray = new JSONArray(objectList);`
`53`	`53`	`} catch (Exception e) {`
`54`		`- System.err.println("Error processing 'content_types': " + e.getMessage());`
	`54`	`+ System.err.println(ErrorMessages.INVALID_CONTENT_TYPE_DATA + " Technical details: " + e.getMessage());`
`55`	`55`	`}`
`56`	`56`	`}`
`57`	`57`	`}`
Original file line number	Diff line number	Diff line change
`@@ -19,7 +19,7 @@ public class Contentstack {`
`19`	`19`
`20`	`20`	`// Modifier Protected`
`21`	`21`	`protected Contentstack() throws IllegalAccessException {`
`22`		`- throw new IllegalAccessException("Can Not Access Private Modifier");`
	`22`	`+ throw new IllegalAccessException(ErrorMessages.DIRECT_INSTANTIATION_CONTENTSTACK);`
`23`	`23`	`}`
`24`	`24`
`25`	`25`	`/**`
`@@ -88,13 +88,13 @@ private static void validateCredentials(String stackApiKey, String deliveryToken`
`88`	`88`	`Objects.requireNonNull(environment, "Environment can not be null");`
`89`	`89`
`90`	`90`	`if (stackApiKey.isEmpty()) {`
`91`		`- throw new IllegalAccessException("API Key can not be empty");`
	`91`	`+ throw new IllegalAccessException(ErrorMessages.MISSING_API_KEY);`
`92`	`92`	`}`
`93`	`93`	`if (deliveryToken.isEmpty()) {`
`94`		`- throw new IllegalAccessException("Delivery Token can not be empty");`
	`94`	`+ throw new IllegalAccessException(ErrorMessages.MISSING_DELIVERY_TOKEN);`
`95`	`95`	`}`
`96`	`96`	`if (environment.isEmpty()) {`
`97`		`- throw new IllegalAccessException("Environment can not be empty");`
	`97`	`+ throw new IllegalAccessException(ErrorMessages.MISSING_ENVIRONMENT);`
`98`	`98`	`}`
`99`	`99`	`}`
`100`	`100`
Original file line number	Diff line number	Diff line change
`@@ -33,7 +33,7 @@ protected EntriesModel(JSONObject responseJSON) {`
`33`	`33`	`}`
`34`	`34`	`} catch (Exception e) {`
`35`	`35`	`Logger logger = Logger.getLogger(EntriesModel.class.getSimpleName());`
`36`		`- logger.log(Level.SEVERE, e.getLocalizedMessage(), e);`
	`36`	`+ logger.log(Level.SEVERE, ErrorMessages.ENTRIES_PROCESSING_FAILED, e);`
`37`	`37`	`}`
`38`	`38`
`39`	`39`	`}`
Original file line number	Diff line number	Diff line change
`@@ -45,7 +45,7 @@ public class Entry {`
`45`	`45`	`protected String rteContent = null;`
`46`	`46`
`47`	`47`	`protected Entry() throws IllegalAccessException {`
`48`		`- throw new IllegalAccessException("Can Not Access Private Modifier");`
	`48`	`+ throw new IllegalAccessException(ErrorMessages.DIRECT_INSTANTIATION_ENTRY);`
`49`	`49`	`}`
`50`	`50`
`51`	`51`	`protected Entry(String contentTypeName) {`
`@@ -503,7 +503,7 @@ public Calendar getDate(@NotNull String key) {`
`503`	`503`	`String value = getString(key);`
`504`	`504`	`return Constants.parseDate(value, null);`
`505`	`505`	`} catch (Exception e) {`
`506`		`- logger.log(Level.SEVERE, e.getLocalizedMessage(), e);`
	`506`	`+ logger.log(Level.SEVERE, ErrorMessages.INVALID_DATE_FORMAT, e);`
`507`	`507`	`}`
`508`	`508`	`return null;`
`509`	`509`	`}`
`@@ -525,7 +525,7 @@ public Calendar getCreateAt() {`
`525`	`525`	`String value = getString("created_at");`
`526`	`526`	`return Constants.parseDate(value, null);`
`527`	`527`	`} catch (Exception e) {`
`528`		`- logger.log(Level.SEVERE, e.getLocalizedMessage(), e);`
	`528`	`+ logger.log(Level.SEVERE, ErrorMessages.INVALID_DATE_FORMAT, e);`
`529`	`529`	`}`
`530`	`530`	`return null;`
`531`	`531`	`}`
`@@ -562,7 +562,7 @@ public Calendar getUpdateAt() {`
`562`	`562`	`String value = getString("updated_at");`
`563`	`563`	`return Constants.parseDate(value, null);`
`564`	`564`	`} catch (Exception e) {`
`565`		`- logger.log(Level.SEVERE, e.getLocalizedMessage(), e);`
	`565`	`+ logger.log(Level.SEVERE, ErrorMessages.INVALID_DATE_FORMAT, e);`
`566`	`566`	`}`
`567`	`567`	`return null;`
`568`	`568`	`}`
`@@ -601,7 +601,7 @@ public Calendar getDeleteAt() {`
`601`	`601`	`String value = getString("deleted_at");`
`602`	`602`	`return Constants.parseDate(value, null);`
`603`	`603`	`} catch (Exception e) {`
`604`		`- logger.log(Level.SEVERE, e.getLocalizedMessage(), e);`
	`604`	`+ logger.log(Level.SEVERE, ErrorMessages.INVALID_DATE_FORMAT, e);`
`605`	`605`	`}`
`606`	`606`	`return null;`
`607`	`607`	`}`
`@@ -764,7 +764,7 @@ public List<Entry> getAllEntries(String refKey, String refContentType) {`
`764`	`764`	`entryInstance = contentType.stackInstance.contentType(refContentType).entry();`
`765`	`765`	`} catch (Exception e) {`
`766`	`766`	`entryInstance = new Entry(refContentType);`
`767`		`- logger.log(Level.SEVERE, e.getLocalizedMessage(), e);`
	`767`	`+ logger.log(Level.SEVERE, ErrorMessages.INVALID_DATE_FORMAT, e);`
`768`	`768`	`}`
`769`	`769`	`entryInstance.setUid(model.uid);`
`770`	`770`	`entryInstance.resultJson = model.jsonObject;`
`@@ -928,9 +928,9 @@ public Entry exceptWithReferenceUid(@NotNull List<String> fieldUid, @NotNull Str`
`928`	`928`	`public void fetch(EntryResultCallBack callback) {`
`929`	`929`	`if (uid.isEmpty()) { // throws IllegalAccessException if uid is Empty`
`930`	`930`	`try {`
`931`		`- throw new IllegalAccessException("Entry Uid is required");`
	`931`	`+ throw new IllegalAccessException(ErrorMessages.ENTRY_UID_REQUIRED);`
`932`	`932`	`} catch (IllegalAccessException e) {`
`933`		`- logger.log(Level.SEVERE, e.getLocalizedMessage(), e);`
	`933`	`+ logger.log(Level.SEVERE, ErrorMessages.ENTRY_FETCH_FAILED, e);`
`934`	`934`	`}`
`935`	`935`	`}`
`936`	`936`	`String urlString = "content_types/" + contentTypeUid + "/entries/" + uid;`