diff --git a/src/main/java/common/GourouException.java b/src/main/java/common/GourouException.java
new file mode 100644
index 0000000..2f92270
--- /dev/null
+++ b/src/main/java/common/GourouException.java
@@ -0,0 +1,71 @@
+package common;
+
+/**
+ * Custom exception class for general Gourou library operations.
+ */
+
+public class GourouException extends RuntimeException
+{
+    public static final int GOUROU_INVALID_CLIENT = 101;
+    public static final int GOUROU_DEVICE_DOES_NOT_MATCH = 102;
+    public static final int GOUROU_ADEPT_ERROR = 103;
+    public static final int GOUROU_FILE_ERROR = 104;
+    public static final int GGOUROU_TAG_NOT_FOUND = 105;
+    public static final int GGOUROU_ADEPT_ERROR = 106;
+    public static final int GGOUROU_FILE_ERROR = 107;
+    public static final int GGOUROU_INVALID_PROPERTY = 108;
+
+    public static final int DRM_ERR_ENCRYPTION_KEY_FP = 201;
+    public static final int DRM_INVALID_USER = 202;
+    public static final int DRM_INVALID_KEY_SIZE = 203;
+    public static final int DRM_ERR_ENCRYPTION_KEY = 204;
+    public static final int DRM_MISSING_PARAMETER = 205;
+    public static final int DRM_IN_OUT_EQUALS = 206;
+    public static final int DRM_VERSION_NOT_SUPPORTED = 207;
+
+    public static final int FF_NOT_ACTIVATED = 301;
+    public static final int FF_INVALID_ACSM_FILE = 302;
+    public static final int FF_SERVER_INTERNAL_ERROR = 303;
+    public static final int FF_NO_HMAC_IN_ACSM_FILE = 304;
+    public static final int FF_NO_OPERATOR_URL = 305;
+    public static final int FF_REQUESTS_EXPIRED = 306;
+
+    public static final int DW_NO_ITEM = 401;
+    public static final int DW_NO_EBX_HANDLER = 402;
+
+    public static final int SIGN_INVALID_CREDENTIALS = 501;
+
+    public static final int CLIENT_ZIP_ERROR = 601; // Example, if Client.zipOpen throws error
+
+    private final int errorCode;
+
+    public GourouException( String message )
+    {
+        super( message );
+        this.errorCode = -1; // Default or unknown error code
+    }
+
+    public GourouException( int errorCode, String message )
+    {
+        super( message );
+        this.errorCode = errorCode;
+    }
+
+    public GourouException( String message, Throwable cause )
+    {
+        super( message, cause );
+        this.errorCode = -1;
+    }
+
+    public GourouException( int errorCode, String message, Throwable cause )
+    {
+        super( message, cause );
+        this.errorCode = errorCode;
+    }
+
+    public int getErrorCode()
+    {
+        return errorCode;
+    }
+}
+