[issue-87]: Added a new feature to get instance count by namespace. (#103)

* feat:#87 Get instance count

* feat:#87 Get instance count Test

* feat:#87 update CHANGES.md

Author: yuhaowin

CHANGES.md

@@ -7,6 +7,7 @@ Apollo Java 2.5.0
 ------------------
 
 * [Feature Provide a new open APl to return the organization list](https://github.com/apolloconfig/apollo-java/pull/102)
+* [Feature Added a new feature to get instance count by namespace.](https://github.com/apolloconfig/apollo-java/pull/103)
 
 ------------------
 All issues and pull requests are [here](https://github.com/apolloconfig/apollo-java/milestone/5?closed=1)

apollo-openapi/src/main/java/com/ctrip/framework/apollo/openapi/api/InstanceOpenApiService.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2024 Apollo Authors
+ *
+ * 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.ctrip.framework.apollo.openapi.api;
+
+public interface InstanceOpenApiService {
+
+    /**
+     * Return instance count by namespace
+     * @since 2.5.0
+     */
+    int getInstanceCountByNamespace(String appId, String env, String clusterName, String namespaceName);
+}

apollo-openapi/src/main/java/com/ctrip/framework/apollo/openapi/client/ApolloOpenApiClient.java

@@ -22,6 +22,7 @@
 import com.ctrip.framework.apollo.openapi.client.service.ItemOpenApiService;
 import com.ctrip.framework.apollo.openapi.client.service.NamespaceOpenApiService;
 import com.ctrip.framework.apollo.openapi.client.service.ReleaseOpenApiService;
+import com.ctrip.framework.apollo.openapi.client.service.InstanceOpenApiService;
 import com.ctrip.framework.apollo.openapi.client.service.OrganizationOpenApiService;
 import com.ctrip.framework.apollo.openapi.dto.*;
 import com.google.common.base.Preconditions;
@@ -51,6 +52,7 @@ public class ApolloOpenApiClient {
   private final ReleaseOpenApiService releaseService;
   private final NamespaceOpenApiService namespaceService;
   private final ClusterOpenApiService clusterService;
+  private final InstanceOpenApiService instanceService;
   private static final Gson GSON = new GsonBuilder().setDateFormat(ApolloOpenApiConstants.JSON_DATE_FORMAT).create();
 
   private ApolloOpenApiClient(String portalUrl, String token, RequestConfig requestConfig) {
@@ -66,6 +68,7 @@ private ApolloOpenApiClient(String portalUrl, String token, RequestConfig reques
     itemService = new ItemOpenApiService(client, baseUrl, GSON);
     releaseService = new ReleaseOpenApiService(client, baseUrl, GSON);
     organizationOpenService = new OrganizationOpenApiService(client, baseUrl, GSON);
+    instanceService = new InstanceOpenApiService(client, baseUrl, GSON);
   }
 
   public void createApp(OpenCreateAppDTO req) {
@@ -243,6 +246,14 @@ public void rollbackRelease(String env, long releaseId, String operator) {
     releaseService.rollbackRelease(env, releaseId, operator);
   }
 
+  /**
+   * Get instance count by namespace
+   * @since 2.5.0
+   */
+  public int getInstanceCountByNamespace(String appId, String env, String clusterName, String namespaceName) {
+    return instanceService.getInstanceCountByNamespace(appId, env, clusterName, namespaceName);
+  }
+
 
   public String getPortalUrl() {
     return portalUrl;

apollo-openapi/src/main/java/com/ctrip/framework/apollo/openapi/client/service/InstanceOpenApiService.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2024 Apollo Authors
+ *
+ * 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.ctrip.framework.apollo.openapi.client.service;
+
+import com.ctrip.framework.apollo.core.ConfigConsts;
+import com.ctrip.framework.apollo.openapi.client.url.OpenApiPathBuilder;
+import com.google.common.base.Strings;
+import com.google.gson.Gson;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.util.EntityUtils;
+
+public class InstanceOpenApiService extends AbstractOpenApiService implements
+        com.ctrip.framework.apollo.openapi.api.InstanceOpenApiService {
+
+    public InstanceOpenApiService(CloseableHttpClient client, String baseUrl, Gson gson) {
+        super(client, baseUrl, gson);
+    }
+
+    @Override
+    public int getInstanceCountByNamespace(String appId, String env, String clusterName, String namespaceName) {
+        if (Strings.isNullOrEmpty(clusterName)) {
+            clusterName = ConfigConsts.CLUSTER_NAME_DEFAULT;
+        }
+        if (Strings.isNullOrEmpty(namespaceName)) {
+            namespaceName = ConfigConsts.NAMESPACE_APPLICATION;
+        }
+
+        checkNotEmpty(appId, "App id");
+        checkNotEmpty(env, "Env");
+
+        OpenApiPathBuilder pathBuilder = OpenApiPathBuilder.newBuilder()
+                .envsPathVal(env)
+                .appsPathVal(appId)
+                .clustersPathVal(clusterName)
+                .namespacesPathVal(namespaceName)
+                .customResource("instances");
+
+        try (CloseableHttpResponse response = get(pathBuilder)) {
+            return gson.fromJson(EntityUtils.toString(response.getEntity()), Integer.class);
+        } catch (Throwable ex) {
+            throw new RuntimeException(String.format("Get instance count: appId: %s, cluster: %s, namespace: %s in env: %s failed",
+                    appId, clusterName, namespaceName, env), ex);
+        }
+    }
+}

apollo-openapi/src/test/java/com/ctrip/framework/apollo/openapi/client/service/InstanceOpenApiServiceTest.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2022 Apollo Authors
+ *
+ * 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.ctrip.framework.apollo.openapi.client.service;
+
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.entity.StringEntity;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.ArgumentCaptor;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.*;
+
+public class InstanceOpenApiServiceTest extends AbstractOpenApiServiceTest {
+
+  private InstanceOpenApiService instanceOpenApiService;
+
+  private String someAppId;
+  private String someEnv;
+  private String someCluster;
+  private String someNamespace;
+
+  @Before
+  public void setUp() throws Exception {
+    super.setUp();
+    someAppId = "someAppId";
+    someEnv = "someEnv";
+    someCluster = "someCluster";
+    someNamespace = "someNamespace";
+    instanceOpenApiService = new InstanceOpenApiService(httpClient, someBaseUrl, gson);
+  }
+
+  @Test
+  public void testGetInstanceCountByNamespace() throws Exception {
+    final ArgumentCaptor<HttpGet> request = ArgumentCaptor.forClass(HttpGet.class);
+
+    StringEntity responseEntity = new StringEntity("1");
+    when(someHttpResponse.getEntity()).thenReturn(responseEntity);
+
+    instanceOpenApiService.getInstanceCountByNamespace(someAppId, someEnv, someCluster, someNamespace);
+
+    verify(httpClient, times(1)).execute(request.capture());
+
+    HttpGet get = request.getValue();
+
+    assertEquals(String.format("%s/envs/%s/apps/%s/clusters/%s/namespaces/%s/instances",
+            someBaseUrl, someEnv, someAppId, someCluster, someNamespace), get.getURI().toString());
+  }
+}

apollo-openapi/src/test/java/com/ctrip/framework/apollo/openapi/client/url/OpenApiPathBuilderTest.java

@@ -224,6 +224,20 @@ public void testBuildPath() {
         .addParam("operator", operator)
         .buildPath(baseURL);
     assertEquals(expected, actual);
+
+    // InstanceOpenApiService path check
+    path = String.format("envs/%s/apps/%s/clusters/%s/namespaces/%s/instances",
+            tools.escapePath(env), tools.escapePath(appId), tools.escapePath(clusterName),
+            tools.escapePath(namespaceName));
+    expected = String.format("%s/%s", baseURL, path);
+    actual = OpenApiPathBuilder.newBuilder()
+            .envsPathVal(env)
+            .appsPathVal(appId)
+            .clustersPathVal(clusterName)
+            .namespacesPathVal(namespaceName)
+            .customResource("instances")
+            .buildPath(baseURL);
+    assertEquals(expected, actual);
   }
 
   @Test(expected = IllegalArgumentException.class)