fix:fix NullPointerException error when using RestTemplate with no label. (#586)

CHANGELOG.md

@@ -37,3 +37,4 @@
 - [refactor:optimize project and code.](https://github.com/Tencent/spring-cloud-tencent/pull/571)
 - [Optimize:change default dynamic config refresh type to reflect.](https://github.com/Tencent/spring-cloud-tencent/pull/575)
 - [feat:optimize examples.](https://github.com/Tencent/spring-cloud-tencent/pull/578)
+- [fix:fix NullPointerException error when using RestTemplate with no label.](https://github.com/Tencent/spring-cloud-tencent/pull/586)

spring-cloud-starter-tencent-polaris-router/src/main/java/com/tencent/cloud/polaris/router/PolarisRouterServiceInstanceListSupplier.java

@@ -25,6 +25,7 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 import com.tencent.cloud.common.constant.RouterConstants;
 import com.tencent.cloud.common.metadata.MetadataContext;
@@ -121,8 +122,12 @@ public class PolarisRouterServiceInstanceListSupplier extends DelegatingServiceI
 
 		Map<String, String> labelHeaderValuesMap = new HashMap<>();
 		try {
-			String labelHeaderValuesContent = labelHeaderValues.stream().findFirst().get();
-			labelHeaderValuesMap.putAll(JacksonUtils.deserialize2Map(URLDecoder.decode(labelHeaderValuesContent, UTF_8)));
+			Optional<String> labelHeaderValuesOptional = labelHeaderValues.stream().findFirst();
+			if (labelHeaderValuesOptional.isPresent()) {
+				String labelHeaderValuesContent = labelHeaderValuesOptional.get();
+				labelHeaderValuesMap.putAll(
+						JacksonUtils.deserialize2Map(URLDecoder.decode(labelHeaderValuesContent, UTF_8)));
+			}
 		}
 		catch (UnsupportedEncodingException e) {
 			throw new RuntimeException("unsupported charset exception " + UTF_8);

spring-cloud-starter-tencent-polaris-router/src/main/java/com/tencent/cloud/polaris/router/resttemplate/PolarisLoadBalancerInterceptor.java

@@ -50,11 +50,13 @@ import org.springframework.http.client.ClientHttpResponse;
 import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 
+import static com.tencent.cloud.common.constant.ContextConstant.UTF_8;
+
 /**
  * PolarisLoadBalancerInterceptor extends LoadBalancerInterceptor capabilities.
  * Parses the label from the request and puts it into the RouterContext for routing.
  *
- *@author lepdou 2022-05-18
+ * @author lepdou, cheese8
  */
 public class PolarisLoadBalancerInterceptor extends LoadBalancerInterceptor {
 	private static final Logger LOGGER = LoggerFactory.getLogger(PolarisLoadBalancerInterceptor.class);
@@ -132,18 +134,14 @@ public class PolarisLoadBalancerInterceptor extends LoadBalancerInterceptor {
 		labels.putAll(transitiveLabels);
 
 		// pass label by header
-		if (labels.size() == 0) {
-			request.getHeaders().set(RouterConstants.ROUTER_LABEL_HEADER, null);
-			return;
-		}
+		String encodedLabelsContent;
 		try {
-			String headerMetadataStr = URLEncoder.encode(JacksonUtils.serialize2Json(labels), "UTF-8");
-			request.getHeaders().set(RouterConstants.ROUTER_LABEL_HEADER, headerMetadataStr);
+			encodedLabelsContent = URLEncoder.encode(JacksonUtils.serialize2Json(labels), UTF_8);
 		}
 		catch (UnsupportedEncodingException e) {
-			LOGGER.error("Set header failed.", e);
-			throw new RuntimeException(e);
+			throw new RuntimeException("unsupported charset exception " + UTF_8);
 		}
+		request.getHeaders().set(RouterConstants.ROUTER_LABEL_HEADER, encodedLabelsContent);
 	}
 
 	private Map<String, String> getExpressionLabels(HttpRequest request, Set<String> labelKeys) {

spring-cloud-tencent-dependencies/pom.xml

@@ -73,7 +73,7 @@
 		<revision>1.7.0-2021.0.3-SNAPSHOT</revision>
 
 		<!-- Dependencies -->
-		<polaris.version>1.7.4-SNAPSHOT</polaris.version>
+		<polaris.version>1.7.4</polaris.version>
 		<guava.version>31.0.1-jre</guava.version>
 		<logback.version>1.2.11</logback.version>
 		<mocktio.version>4.5.1</mocktio.version>