Implementation for Fetching and Caching Server Side Remote Config

src/main/java/com/google/firebase/remoteconfig/AndCondition.java

@@ -0,0 +1,64 @@
+
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.firebase.remoteconfig;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.collect.ImmutableList;
+import com.google.firebase.internal.NonNull;
+import com.google.firebase.remoteconfig.internal.ServerTemplateResponse.AndConditionResponse;
+import com.google.firebase.remoteconfig.internal.ServerTemplateResponse.OneOfConditionResponse;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+final class AndCondition {
+  private final ImmutableList<OneOfCondition> conditions;
+
+  AndCondition(@NonNull List<OneOfCondition> conditions) {
+    checkNotNull(conditions, "List of conditions for AND operation must not be null.");
+    checkArgument(!conditions.isEmpty(), 
+        "List of conditions for AND operation must not be empty.");
+    this.conditions = ImmutableList.copyOf(conditions);
+  }
+
+  AndCondition(AndConditionResponse andConditionResponse) {
+    List<OneOfConditionResponse> conditionList = andConditionResponse.getConditions();
+    checkNotNull(conditionList, "List of conditions for AND operation must not be null.");
+    checkArgument(!conditionList.isEmpty(), 
+        "List of conditions for AND operation must not be empty");
+    this.conditions = conditionList.stream()
+                                  .map(OneOfCondition::new) 
+                                  .collect(ImmutableList.toImmutableList());
+  }
+
+  @NonNull
+  List<OneOfCondition> getConditions() {
+    return new ArrayList<>(conditions);
+  }
+
+  AndConditionResponse toAndConditionResponse() {
+    return new AndConditionResponse()
+                   .setConditions(this.conditions.stream()
+                                                 .map(OneOfCondition::toOneOfConditionResponse)
+                                                 .collect(Collectors.toList()));    
+  }
+}
+

src/main/java/com/google/firebase/remoteconfig/FirebaseRemoteConfig.java

@@ -101,6 +101,73 @@ protected Template execute() throws FirebaseRemoteConfigException {
     };
   }
 
+  /**
+   * Alternative to {@link #getServerTemplate} where developers can initialize with a pre-cached
+   * template or config.
+   */
+  public ServerTemplateImpl.Builder serverTemplateBuilder() {
+    return new ServerTemplateImpl.Builder(this.remoteConfigClient);
+  }
+
+  /**
+   * Initializes a template instance and loads the latest template data.
+   *
+   * @param defaultConfig Default parameter values to use if a getter references a parameter not
+   *     found in the template.
+   * @return A {@link Template} instance with the latest template data.
+   */
+  public ServerTemplate getServerTemplate(KeysAndValues defaultConfig)
+      throws FirebaseRemoteConfigException {
+    return getServerTemplateOp(defaultConfig).call();
+  }
+
+  /**
+   * Initializes a template instance without any defaults and loads the latest template data.
+   *
+   * @return A {@link Template} instance with the latest template data.
+   */
+  public ServerTemplate getServerTemplate() throws FirebaseRemoteConfigException {
+    return getServerTemplate(null);
+  }
+
+  /**
+   * Initializes a template instance and asynchronously loads the latest template data.
+   *
+   * @param defaultConfig Default parameter values to use if a getter references a parameter not
+   *     found in the template.
+   * @return A {@link Template} instance with the latest template data.
+   */
+  public ApiFuture<ServerTemplate> getServerTemplateAsync(KeysAndValues defaultConfig) {
+    return getServerTemplateOp(defaultConfig).callAsync(app);
+  }
+
+  /**
+   * Initializes a template instance without any defaults and asynchronously loads the latest
+   * template data.
+   *
+   * @return A {@link Template} instance with the latest template data.
+   */
+  public ApiFuture<ServerTemplate> getServerTemplateAsync() {
+    return getServerTemplateAsync(null);
+  }
+
+  private CallableOperation<ServerTemplate, FirebaseRemoteConfigException> getServerTemplateOp(
+      KeysAndValues defaultConfig) {
+    return new CallableOperation<ServerTemplate, FirebaseRemoteConfigException>() {
+      @Override
+      protected ServerTemplate execute() throws FirebaseRemoteConfigException {
+        String serverTemplateData = remoteConfigClient.getServerTemplate();
+        ServerTemplate template =
+                serverTemplateBuilder()
+                .defaultConfig(defaultConfig)
+                .cachedTemplate(serverTemplateData)
+                .build();
+
+        return template;
+      }
+    };
+  }
+
   /**
    * Gets the requested version of the of the Remote Config template.
    *
@@ -413,3 +480,4 @@ public void destroy() {
     }
   }
 }
+

src/main/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigClient.java

@@ -40,4 +40,7 @@ Template publishTemplate(Template template, boolean validateOnly,
 
   ListVersionsResponse listVersions(
           ListVersionsOptions options) throws FirebaseRemoteConfigException;
+
+  String getServerTemplate() throws FirebaseRemoteConfigException;
 }
+

src/main/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigClientImpl.java

@@ -38,6 +38,7 @@
 import com.google.firebase.internal.NonNull;
 import com.google.firebase.internal.SdkUtils;
 import com.google.firebase.remoteconfig.internal.RemoteConfigServiceErrorResponse;
+import com.google.firebase.remoteconfig.internal.ServerTemplateResponse;
 import com.google.firebase.remoteconfig.internal.TemplateResponse;
 
 import java.io.IOException;
@@ -51,6 +52,9 @@ final class FirebaseRemoteConfigClientImpl implements FirebaseRemoteConfigClient
 
   private static final String REMOTE_CONFIG_URL = "https://firebaseremoteconfig.googleapis.com/v1/projects/%s/remoteConfig";
 
+  private static final String SERVER_REMOTE_CONFIG_URL =
+      "https://firebaseremoteconfig.googleapis.com/v1/projects/%s/namespaces/firebase-server/serverRemoteConfig";
+
   private static final Map<String, String> COMMON_HEADERS =
           ImmutableMap.of(
                   "X-Firebase-Client", "fire-admin-java/" + SdkUtils.getVersion(),
@@ -62,13 +66,15 @@ final class FirebaseRemoteConfigClientImpl implements FirebaseRemoteConfigClient
           );
 
   private final String remoteConfigUrl;
+  private final String serverRemoteConfigUrl;
   private final HttpRequestFactory requestFactory;
   private final JsonFactory jsonFactory;
   private final ErrorHandlingHttpClient<FirebaseRemoteConfigException> httpClient;
 
   private FirebaseRemoteConfigClientImpl(Builder builder) {
     checkArgument(!Strings.isNullOrEmpty(builder.projectId));
     this.remoteConfigUrl = String.format(REMOTE_CONFIG_URL, builder.projectId);
+    this.serverRemoteConfigUrl = String.format(SERVER_REMOTE_CONFIG_URL, builder.projectId);
     this.requestFactory = checkNotNull(builder.requestFactory);
     this.jsonFactory = checkNotNull(builder.jsonFactory);
     HttpResponseInterceptor responseInterceptor = builder.responseInterceptor;
@@ -82,6 +88,11 @@ String getRemoteConfigUrl() {
     return remoteConfigUrl;
   }
 
+  @VisibleForTesting
+  String getServerRemoteConfigUrl() {
+    return serverRemoteConfigUrl;
+  }
+
   @VisibleForTesting
   HttpRequestFactory getRequestFactory() {
     return requestFactory;
@@ -102,6 +113,18 @@ public Template getTemplate() throws FirebaseRemoteConfigException {
     return template.setETag(getETag(response));
   }
 
+  @Override
+  public String getServerTemplate() throws FirebaseRemoteConfigException {
+    HttpRequestInfo request =
+        HttpRequestInfo.buildGetRequest(serverRemoteConfigUrl).addAllHeaders(COMMON_HEADERS);
+    IncomingHttpResponse response = httpClient.send(request);
+    ServerTemplateResponse templateResponse = httpClient.parse(response, 
+                                ServerTemplateResponse.class);
+    ServerTemplateData serverTemplateData = new ServerTemplateData(templateResponse);
+    serverTemplateData.setETag(getETag(response));
+    return serverTemplateData.toJSON(); 
+  }
+
   @Override
   public Template getTemplateAtVersion(
           @NonNull String versionNumber) throws FirebaseRemoteConfigException {
@@ -267,3 +290,4 @@ private RemoteConfigServiceErrorResponse safeParse(String response) {
     }
   }
 }
+

src/main/java/com/google/firebase/remoteconfig/KeysAndValues.java

@@ -0,0 +1,136 @@
+
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.firebase.remoteconfig;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableMap;
+import com.google.firebase.internal.NonNull;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Represents data stored in context passed to server-side Remote Config.
+ */
+public class KeysAndValues {
+  final ImmutableMap<String, String> keysAndValues;
+
+  private KeysAndValues(@NonNull Builder builder) {
+    keysAndValues = ImmutableMap.<String, String>builder().putAll(builder.keysAndValues).build(); 
+  }
+
+  /**
+   * Checks whether a key is present in the context.
+   * 
+   * @param key The key for data stored in context.
+   * @return Boolean representing whether the key passed is present in context.
+   */
+  public boolean containsKey(String key) {
+    return keysAndValues.containsKey(key);
+  }
+
+  /**
+   * Gets the value of the data stored in context.
+   * 
+   * @param key The key for data stored in context.
+   * @return Value assigned to the key in context.
+   */
+  public String get(String key) {
+    return keysAndValues.get(key);
+  }
+
+  /**
+   * Builder class for KeysAndValues using which values will be assigned to
+   * private variables.
+   */
+  public static class Builder {
+    // Holds the converted pairs of custom keys and values.
+    private final Map<String, String> keysAndValues = new HashMap<>();
+
+    /**
+     * Adds a context data with string value.
+     * 
+     * @param key   Identifies the value in context.
+     * @param value Value assigned to the context.
+     * @return Reference to class itself so that more data can be added.
+     */
+    @NonNull
+    public Builder put(@NonNull String key, @NonNull String value) {
+      checkArgument(!Strings.isNullOrEmpty(key), "Context key must not be null or empty.");
+      checkArgument(!Strings.isNullOrEmpty(value), "Context key must not be null or empty.");
+      keysAndValues.put(key, value);
+      return this;
+    }
+
+    /**
+     * Adds a context data with boolean value.
+     * 
+     * @param key   Identifies the value in context.
+     * @param value Value assigned to the context.
+     * @return Reference to class itself so that more data can be added.
+     */
+    @NonNull
+    public Builder put(@NonNull String key, boolean value) {
+      checkArgument(!Strings.isNullOrEmpty(key), "Context key must not be null or empty.");
+      keysAndValues.put(key, Boolean.toString(value));
+      return this;
+    }
+
+    /**
+     * Adds a context data with double value.
+     * 
+     * @param key   Identifies the value in context.
+     * @param value Value assigned to the context.
+     * @return Reference to class itself so that more data can be added.
+     */
+    @NonNull
+    public Builder put(@NonNull String key, double value) {
+      checkArgument(!Strings.isNullOrEmpty(key), "Context key must not be null or empty.");
+      keysAndValues.put(key, Double.toString(value));
+      return this;
+    }
+
+    /**
+     * Adds a context data with long value.
+     * 
+     * @param key   Identifies the value in context.
+     * @param value Value assigned to the context.
+     * @return Reference to class itself so that more data can be added.
+     */
+    @NonNull
+    public Builder put(@NonNull String key, long value) {
+      checkArgument(!Strings.isNullOrEmpty(key), "Context key must not be null or empty.");
+      keysAndValues.put(key, Long.toString(value));
+      return this;
+    }
+
+    /**
+     * Creates an instance of KeysAndValues with the values assigned through
+     * builder.
+     * 
+     * @return instance of KeysAndValues
+     */
+    @NonNull
+    public KeysAndValues build() {
+      return new KeysAndValues(this);
+    }
+  }
+}
+