Add locale support to Asset and AssetLibrary classes

- Introduced `language` field in Asset and AssetModel to store locale information.
- Added `setLocale` and `getLocale` methods in Asset and AssetLibrary for locale management.
- Updated tests to verify locale functionality in Asset, AssetLibrary, and AssetModel.

src/main/java/com/contentstack/sdk/Asset.java

@@ -43,6 +43,7 @@ public class Asset {
     protected String fileSize = null;
     protected String fileName = null;
     protected String uploadUrl = null;
+    protected String language = null;
     protected JSONObject json = null;
     protected String[] tagsArray = null;
     protected LinkedHashMap<String, Object> headers;
@@ -75,6 +76,7 @@ public Asset configure(JSONObject jsonObject) {
         this.contentType = model.contentType;
         this.fileSize = model.fileSize;
         this.uploadUrl = model.uploadUrl;
+        this.language = model.language;
         this.fileName = model.fileName;
         this.json = model.json;
         this.assetUid = model.uploadedUid;
@@ -558,6 +560,38 @@ public Asset assetFields(String... fields) {
         return this;
     }
 
+    /**
+     * Specifies the fields to be included in the asset response.
+     * <p>
+     * This method allows you to specify one or more field names, and only those fields
+     * will be included in the returned asset data. This is useful for reducing response size
+     * and fetching only the required asset properties.
+     *
+     * @param fields Variable number of field names to be included in the asset response.
+     * @return The {@link Asset} instance for chaining further calls.
+     *
+     * <b>Example:</b><br>
+     * <pre class="prettyprint">
+     * Asset asset = stack.asset("asset_uid");
+     * asset.assetFields("title", "filename");
+     * </pre>
+     */
+
+    public Asset setLocale(String locale) {
+        urlQueries.put("locale",locale);
+        return this;
+    }
+
+
+    /**
+     * Returns the locale (language) associated with this asset.
+     *
+     * @return The asset's locale as a {@link String}, or {@code null} if not set.
+     */
+    public String getLocale() {
+        return this.language;
+    }
+
     /**
      * Fetch.
      *

src/main/java/com/contentstack/sdk/AssetLibrary.java

@@ -151,6 +151,28 @@ public AssetLibrary includeMetadata() {
         return this;
     }
 
+    /**
+     * Sets the locale for asset queries.
+     * <p>
+     * This method allows you to specify a locale code, so asset results are returned 
+     * for a particular language or region. If not explicitly set, the default locale 
+     * configured in the stack will be used.
+     *
+     * @param locale The locale code to filter assets by (e.g., "en-us").
+     * @return The {@link AssetLibrary} instance for method chaining.
+     *
+     * <b>Example:</b>
+     * <pre class="prettyprint">
+     * Stack stack = Contentstack.stack("apiKey", "deliveryToken", "environment");
+     * AssetLibrary assetLibrary = stack.assetLibrary();
+     * assetLibrary.setLocale("en-us");
+     * </pre>
+     */
+    public AssetLibrary setLocale(String locale) {
+        urlQueries.put("locale",locale);
+        return this;
+    }
+
     /**
      * Gets count.
      *

src/main/java/com/contentstack/sdk/AssetModel.java

@@ -21,6 +21,7 @@ class AssetModel {
     String fileSize;
     String fileName;
     String uploadUrl;
+    String language;
     String[] tags;
     JSONObject json;
     int count = 0;
@@ -45,6 +46,7 @@ public AssetModel(JSONObject response, boolean isArray) {
             fileSize = (String) json.opt("file_size");
             fileName = (String) json.opt("filename");
             uploadUrl = (String) json.opt("url");
+            language = (String) json.opt("locale");
             if (json.opt("tags") instanceof JSONArray) {
                 extractTags();
             }

src/test/java/com/contentstack/sdk/TestAsset.java

@@ -81,6 +81,79 @@ void testConfigureWithMinimalJson() {
         assertSame(asset, result);
     }
 
+    @Test
+    void testConfigureWithLocaleSetsLanguage() {
+        JSONObject json = new JSONObject();
+        json.put("uid", "locale_asset_uid");
+        json.put("locale", "en-us");
+        json.put("filename", "localized.jpg");
+
+        asset.configure(json);
+        assertEquals("en-us", asset.getLocale());
+        assertEquals("en-us", asset.language);
+    }
+
+    @Test
+    void testConfigureWithoutLocaleLeavesLanguageNull() {
+        JSONObject json = new JSONObject();
+        json.put("uid", "no_locale_uid");
+        json.put("filename", "test.jpg");
+
+        asset.configure(json);
+        assertNull(asset.getLocale());
+        assertNull(asset.language);
+    }
+
+    // ========== LOCALE TESTS (setLocale / getLocale) ==========
+
+    @Test
+    void testSetLocale() {
+        Asset result = asset.setLocale("en-us");
+        assertSame(asset, result);
+        assertTrue(asset.urlQueries.has("locale"));
+        assertEquals("en-us", asset.urlQueries.get("locale"));
+    }
+
+    @Test
+    void testSetLocaleReturnsThisForChaining() {
+        Asset result = asset.setLocale("fr-fr").includeDimension().includeMetadata();
+        assertSame(asset, result);
+        assertEquals("fr-fr", asset.urlQueries.get("locale"));
+        assertTrue(asset.urlQueries.has("include_dimension"));
+        assertTrue(asset.urlQueries.has("include_metadata"));
+    }
+
+    @Test
+    void testSetLocaleOverwritesPrevious() {
+        asset.setLocale("en-us");
+        assertEquals("en-us", asset.urlQueries.get("locale"));
+        asset.setLocale("de-de");
+        assertEquals("de-de", asset.urlQueries.get("locale"));
+    }
+
+    @Test
+    void testGetLocaleBeforeConfigureReturnsNull() {
+        assertNull(asset.getLocale());
+    }
+
+    @Test
+    void testGetLocaleAfterConfigureWithLocale() {
+        JSONObject json = new JSONObject();
+        json.put("uid", "uid");
+        json.put("locale", "ja-jp");
+        asset.configure(json);
+        assertEquals("ja-jp", asset.getLocale());
+    }
+
+    @Test
+    void testGetLocaleAfterSetLocaleOnlySetsQueryNotLanguage() {
+        asset.setLocale("es-es");
+        // setLocale only puts in urlQueries; it does not set this.language
+        assertTrue(asset.urlQueries.has("locale"));
+        assertEquals("es-es", asset.urlQueries.get("locale"));
+        assertNull(asset.getLocale()); // getLocale returns this.language, not urlQueries
+    }
+
     // ========== HEADER TESTS ==========
 
     @Test

src/test/java/com/contentstack/sdk/TestAssetLibrary.java

@@ -136,6 +136,41 @@ void testIncludeMetadata() {
         assertEquals(true, assetLibrary.urlQueries.get("include_metadata"));
     }
 
+    // ========== LOCALE TESTS (setLocale for asset localisation) ==========
+
+    @Test
+    void testSetLocale() {
+        AssetLibrary result = assetLibrary.setLocale("en-us");
+        assertSame(assetLibrary, result);
+        assertTrue(assetLibrary.urlQueries.has("locale"));
+        assertEquals("en-us", assetLibrary.urlQueries.get("locale"));
+    }
+
+    @Test
+    void testSetLocaleReturnsThisForChaining() {
+        AssetLibrary result = assetLibrary.setLocale("fr-fr").includeCount().limit(10);
+        assertSame(assetLibrary, result);
+        assertEquals("fr-fr", assetLibrary.urlQueries.get("locale"));
+        assertTrue(assetLibrary.urlQueries.has("include_count"));
+        assertEquals(10, assetLibrary.urlQueries.get("limit"));
+    }
+
+    @Test
+    void testSetLocaleOverwritesPrevious() {
+        assetLibrary.setLocale("en-us");
+        assertEquals("en-us", assetLibrary.urlQueries.get("locale"));
+        assetLibrary.setLocale("de-de");
+        assertEquals("de-de", assetLibrary.urlQueries.get("locale"));
+    }
+
+    @Test
+    void testSetLocaleWithVariousLocaleCodes() {
+        assetLibrary.setLocale("ja-jp");
+        assertEquals("ja-jp", assetLibrary.urlQueries.get("locale"));
+        assetLibrary.setLocale("pt-br");
+        assertEquals("pt-br", assetLibrary.urlQueries.get("locale"));
+    }
+
     // ========== ASSET FIELDS TESTS (CDA asset_fields[] parameter) ==========
 
     @Test

src/test/java/com/contentstack/sdk/TestAssetModel.java

@@ -212,6 +212,70 @@ void testConstructorWithAllFields() {
         assertEquals(2, model.tags.length);
     }
 
+    // ========== LOCALE / LANGUAGE TESTS (asset localisation) ==========
+
+    @Test
+    void testConstructorWithLocaleIsArrayTrue() {
+        JSONObject response = new JSONObject();
+        response.put("uid", "localized_asset");
+        response.put("filename", "localized.jpg");
+        response.put("locale", "en-us");
+
+        AssetModel model = new AssetModel(response, true);
+
+        assertNotNull(model);
+        assertEquals("localized_asset", model.uploadedUid);
+        assertEquals("en-us", model.language);
+    }
+
+    @Test
+    void testConstructorWithoutLocaleLeavesLanguageNull() {
+        JSONObject response = new JSONObject();
+        response.put("uid", "no_locale_asset");
+        response.put("filename", "test.jpg");
+
+        AssetModel model = new AssetModel(response, true);
+
+        assertNotNull(model);
+        assertNull(model.language);
+    }
+
+    @Test
+    void testConstructorWithVariousLocaleCodes() {
+        JSONObject response = new JSONObject();
+        response.put("uid", "uid");
+        response.put("locale", "fr-fr");
+
+        AssetModel model = new AssetModel(response, true);
+        assertEquals("fr-fr", model.language);
+
+        JSONObject response2 = new JSONObject();
+        response2.put("uid", "uid2");
+        response2.put("locale", "ja-jp");
+        AssetModel model2 = new AssetModel(response2, true);
+        assertEquals("ja-jp", model2.language);
+    }
+
+    @Test
+    void testConstructorWithLocaleAndOtherFields() {
+        JSONObject response = new JSONObject();
+        response.put("uid", "full_localized");
+        response.put("content_type", "image/png");
+        response.put("file_size", "1024");
+        response.put("filename", "image.png");
+        response.put("url", "https://cdn.example.com/image.png");
+        response.put("locale", "de-de");
+
+        AssetModel model = new AssetModel(response, true);
+
+        assertEquals("full_localized", model.uploadedUid);
+        assertEquals("image/png", model.contentType);
+        assertEquals("1024", model.fileSize);
+        assertEquals("image.png", model.fileName);
+        assertEquals("https://cdn.example.com/image.png", model.uploadUrl);
+        assertEquals("de-de", model.language);
+    }
+
     @Test
     void testConstructorWithMinimalData() {
         JSONObject response = new JSONObject();