feat: support least connection loadbalancer

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

@@ -35,7 +35,7 @@ import org.springframework.context.annotation.Configuration;
  * @author Haotian Zhang
  */
 @Configuration(proxyBeanMethods = false)
-@EnableConfigurationProperties(PolairsShortestResponseTimeLoadBalancerProperties.class)
+@EnableConfigurationProperties
 @ConditionalOnDiscoveryEnabled
 @ConditionalOnPolarisEnabled
 @ConditionalOnProperty(value = "spring.cloud.polaris.loadbalancer.enabled", matchIfMissing = true)

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

@@ -0,0 +1,171 @@
+/*
+ * Tencent is pleased to support the open source community by making spring-cloud-tencent available.
+ *
+ * Copyright (C) 2021 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.loadbalancer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.tencent.cloud.common.metadata.StaticMetadataManager;
+import com.tencent.cloud.common.metadata.config.MetadataLocalProperties;
+import com.tencent.cloud.common.pojo.PolarisServiceInstance;
+import com.tencent.cloud.common.util.ApplicationContextAwareUtils;
+import com.tencent.polaris.api.exception.ErrorCode;
+import com.tencent.polaris.api.exception.PolarisException;
+import com.tencent.polaris.api.pojo.Instance;
+import com.tencent.polaris.router.api.core.RouterAPI;
+import com.tencent.polaris.router.api.rpc.ProcessLoadBalanceResponse;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.MockedStatic;
+import org.mockito.Mockito;
+import org.mockito.junit.jupiter.MockitoExtension;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.loadbalancer.Request;
+import org.springframework.cloud.client.loadbalancer.Response;
+import org.springframework.cloud.loadbalancer.core.NoopServiceInstanceListSupplier;
+import org.springframework.cloud.loadbalancer.core.ServiceInstanceListSupplier;
+import org.springframework.context.ApplicationContext;
+
+import static com.tencent.cloud.common.metadata.MetadataContext.LOCAL_NAMESPACE;
+import static com.tencent.cloud.common.metadata.MetadataContext.LOCAL_SERVICE;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+/**
+ * PolarisShortestResponseTimeLoadBalancerTest.
+ *
+ * @author Yuwei Fu
+ */
+@ExtendWith(MockitoExtension.class)
+public class PolarisLeastConnectionLoadBalancerTest {
+
+	private static MockedStatic<ApplicationContextAwareUtils> mockedApplicationContextAwareUtils;
+	private static Instance testInstance;
+	@Mock
+	private RouterAPI routerAPI;
+	@Mock
+	private ObjectProvider<ServiceInstanceListSupplier> supplierObjectProvider;
+
+	@BeforeAll
+	static void beforeAll() {
+		mockedApplicationContextAwareUtils = Mockito.mockStatic(ApplicationContextAwareUtils.class);
+		mockedApplicationContextAwareUtils.when(() -> ApplicationContextAwareUtils.getProperties(anyString()))
+				.thenReturn("unit-test");
+		ApplicationContext applicationContext = mock(ApplicationContext.class);
+		MetadataLocalProperties metadataLocalProperties = mock(MetadataLocalProperties.class);
+		StaticMetadataManager staticMetadataManager = mock(StaticMetadataManager.class);
+		doReturn(metadataLocalProperties).when(applicationContext).getBean(MetadataLocalProperties.class);
+		doReturn(staticMetadataManager).when(applicationContext).getBean(StaticMetadataManager.class);
+		mockedApplicationContextAwareUtils.when(ApplicationContextAwareUtils::getApplicationContext)
+				.thenReturn(applicationContext);
+		testInstance = Instance.createDefaultInstance("instance-id", LOCAL_NAMESPACE,
+				LOCAL_SERVICE, "host", 8090);
+	}
+
+	@AfterAll
+	static void afterAll() {
+		mockedApplicationContextAwareUtils.close();
+	}
+
+	@Test
+	public void chooseNormalLogicTest_thenReturnAvailablePolarisInstance() {
+		Request request = Mockito.mock(Request.class);
+		List<ServiceInstance> mockInstanceList = new ArrayList<>();
+		mockInstanceList.add(new PolarisServiceInstance(testInstance));
+
+		ServiceInstanceListSupplier serviceInstanceListSupplier = Mockito.mock(ServiceInstanceListSupplier.class);
+		when(serviceInstanceListSupplier.get(request)).thenReturn(Flux.just(mockInstanceList));
+
+		when(supplierObjectProvider.getIfAvailable(any())).thenReturn(serviceInstanceListSupplier);
+
+		ProcessLoadBalanceResponse mockLbRes = new ProcessLoadBalanceResponse(testInstance);
+		when(routerAPI.processLoadBalance(any())).thenReturn(mockLbRes);
+
+		// request construct and execute invoke
+		PolarisLeastConnectionLoadBalancer polarisLeastConnectionLoadBalancer = new PolarisLeastConnectionLoadBalancer(LOCAL_SERVICE, supplierObjectProvider, routerAPI);
+		Mono<Response<ServiceInstance>> responseMono = polarisLeastConnectionLoadBalancer.choose(request);
+		ServiceInstance serviceInstance = responseMono.block().getServer();
+
+		// verify method has invoked
+		verify(supplierObjectProvider).getIfAvailable(any());
+
+		//result assert
+		Assertions.assertThat(serviceInstance).isNotNull();
+		Assertions.assertThat(serviceInstance instanceof PolarisServiceInstance).isTrue();
+
+		PolarisServiceInstance polarisServiceInstance = (PolarisServiceInstance) serviceInstance;
+
+		Assertions.assertThat(polarisServiceInstance.getPolarisInstance().getId()).isEqualTo("instance-id");
+		Assertions.assertThat(polarisServiceInstance.getPolarisInstance().getNamespace()).isEqualTo(LOCAL_NAMESPACE);
+		Assertions.assertThat(polarisServiceInstance.getPolarisInstance().getService()).isEqualTo(LOCAL_SERVICE);
+		Assertions.assertThat(polarisServiceInstance.getPolarisInstance().getHost()).isEqualTo("host");
+		Assertions.assertThat(polarisServiceInstance.getPolarisInstance().getPort()).isEqualTo(8090);
+	}
+
+	@Test
+	public void chooseExceptionTest_thenReturnEmptyInstance() {
+
+		Request request = Mockito.mock(Request.class);
+		List<ServiceInstance> mockInstanceList = new ArrayList<>();
+		mockInstanceList.add(new PolarisServiceInstance(testInstance));
+
+		ServiceInstanceListSupplier serviceInstanceListSupplier = Mockito.mock(ServiceInstanceListSupplier.class);
+		when(serviceInstanceListSupplier.get(request)).thenReturn(Flux.just(mockInstanceList));
+
+		when(supplierObjectProvider.getIfAvailable(any())).thenReturn(serviceInstanceListSupplier);
+
+		when(routerAPI.processLoadBalance(any())).thenThrow(new PolarisException(ErrorCode.API_TIMEOUT));
+
+		// request construct and execute invoke
+		PolarisShortestResponseTimeLoadBalancer polarisShortestResponseTimeLoadBalancer = new PolarisShortestResponseTimeLoadBalancer(LOCAL_SERVICE, supplierObjectProvider, routerAPI);
+		Mono<Response<ServiceInstance>> responseMono = polarisShortestResponseTimeLoadBalancer.choose(request);
+		ServiceInstance serviceInstance = responseMono.block().getServer();
+
+		// verify method has invoked
+		verify(supplierObjectProvider).getIfAvailable(any());
+
+		//result assert
+		Assertions.assertThat(serviceInstance).isNull();
+	}
+
+	@Test
+	public void chooseEmptySupplierTest_thenReturnEmptyInstance() {
+		ServiceInstanceListSupplier noopSupplier = new NoopServiceInstanceListSupplier();
+		when(supplierObjectProvider.getIfAvailable(any())).thenReturn(noopSupplier);
+
+		// request construct and execute invoke
+		PolarisShortestResponseTimeLoadBalancer polarisShortestResponseTimeLoadBalancer = new PolarisShortestResponseTimeLoadBalancer(LOCAL_SERVICE, supplierObjectProvider, routerAPI);
+		Mono<Response<ServiceInstance>> responseMono = polarisShortestResponseTimeLoadBalancer.choose();
+		ServiceInstance serviceInstance = responseMono.block().getServer();
+
+		//result assert
+		Assertions.assertThat(serviceInstance).isNull();
+	}
+}

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

@@ -64,7 +64,7 @@ import static org.mockito.Mockito.when;
  * @author Yuwei Fu
  */
 @ExtendWith(MockitoExtension.class)
-public class PolarisShortestResponseTimeBalancerTest {
+public class PolarisShortestResponseTimeLoadBalancerTest {
 
 	private static MockedStatic<ApplicationContextAwareUtils> mockedApplicationContextAwareUtils;
 	private static Instance testInstance;