feat:refactor SDKContext as static.

spring-cloud-starter-tencent-polaris-discovery/src/main/java/com/tencent/cloud/polaris/discovery/PolarisDiscoveryHandler.java

@@ -68,7 +68,7 @@ public InstancesResponse getInstances(String service) {
 		GetAllInstancesRequest request = new GetAllInstancesRequest();
 		request.setNamespace(namespace);
 		request.setService(service);
-		return polarisConsumer.getAllInstance(request);
+		return polarisConsumer.getAllInstances(request);
 	}
 
 	/**

spring-cloud-starter-tencent-polaris-discovery/src/test/java/com/tencent/cloud/polaris/discovery/PolarisDiscoveryHandlerTest.java

@@ -0,0 +1,65 @@
+/*
+ * Tencent is pleased to support the open source community by making Spring Cloud Tencent available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ *
+ * Licensed under the BSD 3-Clause License (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://opensource.org/licenses/BSD-3-Clause
+ *
+ * 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.tencent.cloud.polaris.discovery;
+
+import com.tencent.cloud.polaris.PolarisDiscoveryProperties;
+import com.tencent.cloud.polaris.context.PolarisSDKContextManager;
+import com.tencent.polaris.api.core.ConsumerAPI;
+import com.tencent.polaris.api.exception.PolarisException;
+import com.tencent.polaris.api.rpc.ServicesResponse;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import static com.tencent.polaris.test.common.Consts.NAMESPACE_TEST;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Test for {@link PolarisDiscoveryHandler}.
+ *
+ * @author Haotian Zhang
+ */
+@ExtendWith(MockitoExtension.class)
+public class PolarisDiscoveryHandlerTest {
+
+	private PolarisDiscoveryHandler polarisDiscoveryHandler;
+
+	@BeforeEach
+	void setUp() {
+		PolarisDiscoveryProperties polarisDiscoveryProperties = mock(PolarisDiscoveryProperties.class);
+		doReturn(NAMESPACE_TEST).when(polarisDiscoveryProperties).getNamespace();
+
+		ConsumerAPI consumerAPI = mock(ConsumerAPI.class);
+		ServicesResponse servicesResponse = mock(ServicesResponse.class);
+		doReturn(servicesResponse).when(consumerAPI).getServices(any());
+
+		PolarisSDKContextManager polarisSDKContextManager = mock(PolarisSDKContextManager.class);
+		doReturn(consumerAPI).when(polarisSDKContextManager).getConsumerAPI();
+		polarisDiscoveryHandler = new PolarisDiscoveryHandler(polarisDiscoveryProperties, polarisSDKContextManager);
+	}
+
+	@Test
+	public void testGetServices() throws PolarisException {
+		ServicesResponse servicesResponse = polarisDiscoveryHandler.getServices();
+		assertThat(servicesResponse).isNotNull();
+	}
+}