From e41751573a194e4e263b91a065eb43121dc3b20f Mon Sep 17 00:00:00 2001
From: reeshika-h <reeshika.hosmani@contentstack.com>
Date: Tue, 2 Sep 2025 11:21:25 +0530
Subject: [PATCH] Refactor error handling to use ErrorMessages constants for
 consistency in Contentstack, InvalidInputException, JSONUTF8Request, and
 NodeToHTML classes

---
 .../com/contentstack/sdk/Contentstack.java    |  2 +-
 .../com/contentstack/sdk/ErrorMessages.java   | 33 +++++++++++++++++++
 .../sdk/InvalidInputException.java            |  2 +-
 .../com/contentstack/sdk/JSONUTF8Request.java |  4 +--
 .../java/com/contentstack/sdk/NodeToHTML.java |  2 +-
 5 files changed, 38 insertions(+), 5 deletions(-)
 create mode 100644 contentstack/src/main/java/com/contentstack/sdk/ErrorMessages.java

diff --git a/contentstack/src/main/java/com/contentstack/sdk/Contentstack.java b/contentstack/src/main/java/com/contentstack/sdk/Contentstack.java
index 97fe6402..5d10650e 100755
--- a/contentstack/src/main/java/com/contentstack/sdk/Contentstack.java
+++ b/contentstack/src/main/java/com/contentstack/sdk/Contentstack.java
@@ -27,7 +27,7 @@ public class Contentstack {
     private static Contentstack instance;
 
     private Contentstack(Context context) {
-        throw new IllegalStateException("Private constructor not allowed");
+        throw new IllegalStateException(ErrorMessages.PRIVATE_CONSTRUCTOR_NOT_ALLOWED);
     }
 
     /**
diff --git a/contentstack/src/main/java/com/contentstack/sdk/ErrorMessages.java b/contentstack/src/main/java/com/contentstack/sdk/ErrorMessages.java
new file mode 100644
index 00000000..d80a7880
--- /dev/null
+++ b/contentstack/src/main/java/com/contentstack/sdk/ErrorMessages.java
@@ -0,0 +1,33 @@
+package com.contentstack.sdk;
+
+/**
+ * Contains all error messages used across the SDK.
+ * Centralizing messages here makes it easier to maintain and update them.
+ */
+public final class ErrorMessages {
+    private ErrorMessages() {
+        throw new IllegalStateException("Utility class - do not instantiate");
+    }
+
+    // Constructor related errors
+    public static final String PRIVATE_CONSTRUCTOR_NOT_ALLOWED = 
+        "This class does not support private constructors. Use a public constructor to create an instance.";
+    public static final String UTILITY_CLASS_INSTANTIATION = 
+        "This is a utility class and cannot be instantiated";
+    public static final String NODE_TO_HTML_INSTANTIATION = 
+        "Failed to create an instance of NodeToHTML, you can directly access the methods of this class";
+
+    // Input validation errors
+    public static final String NULL_OR_EMPTY_INPUT = 
+        "The input value cannot be null or empty. Provide a valid string to continue.";
+    
+    // Network and parsing errors
+    public static final String ENCODING_ERROR = 
+        "The system encountered an encoding issue while processing your request. Try again or contact support.";
+    public static final String JSON_PARSING_ERROR = 
+        "We couldn't process the response due to a data formatting issue. Try again or contact support if the problem persists.";
+
+    // Cache related errors
+    public static final String CACHE_INITIALIZATION_ERROR = 
+        "Failed to initialize cache. The application will continue without caching.";
+}
diff --git a/contentstack/src/main/java/com/contentstack/sdk/InvalidInputException.java b/contentstack/src/main/java/com/contentstack/sdk/InvalidInputException.java
index 37720f1f..950a1018 100644
--- a/contentstack/src/main/java/com/contentstack/sdk/InvalidInputException.java
+++ b/contentstack/src/main/java/com/contentstack/sdk/InvalidInputException.java
@@ -13,7 +13,7 @@
  * <code>
  * public void processInput(String input) throws InvalidInputException {
  * if (input == null || input.isEmpty()) {
- * throw new InvalidInputException("Input cannot be null or empty");
+ * throw new InvalidInputException(ErrorMessages.NULL_OR_EMPTY_INPUT);
  * }
  * // Process the input here
  * }
diff --git a/contentstack/src/main/java/com/contentstack/sdk/JSONUTF8Request.java b/contentstack/src/main/java/com/contentstack/sdk/JSONUTF8Request.java
index d9bc6913..40486733 100755
--- a/contentstack/src/main/java/com/contentstack/sdk/JSONUTF8Request.java
+++ b/contentstack/src/main/java/com/contentstack/sdk/JSONUTF8Request.java
@@ -24,9 +24,9 @@ protected Response<JSONObject> parseNetworkResponse(NetworkResponse response) {
             String jsonString = new String(response.data, "UTF-8");
             return Response.success(new JSONObject(jsonString), HttpHeaderParser.parseCacheHeaders(response));
         } catch (UnsupportedEncodingException e) {
-            return Response.error(new ParseError(e));
+            return Response.error(new ParseError(new UnsupportedEncodingException(ErrorMessages.ENCODING_ERROR)));
         } catch (JSONException je) {
-            return Response.error(new ParseError(je));
+            return Response.error(new ParseError(new JSONException(ErrorMessages.JSON_PARSING_ERROR)));
         }
     }
 
diff --git a/contentstack/src/main/java/com/contentstack/sdk/NodeToHTML.java b/contentstack/src/main/java/com/contentstack/sdk/NodeToHTML.java
index e290582a..21e9e632 100644
--- a/contentstack/src/main/java/com/contentstack/sdk/NodeToHTML.java
+++ b/contentstack/src/main/java/com/contentstack/sdk/NodeToHTML.java
@@ -4,7 +4,7 @@
 
 public class NodeToHTML {
     private NodeToHTML() {
-        throw new IllegalStateException("Could not create instance of NodeToHTML");
+        throw new IllegalStateException(ErrorMessages.NODE_TO_HTML_INSTANTIATION);
     }
     public static String textNodeToHTML(JSONObject nodeText, Option renderOption) {
         String text = nodeText.optString("text");