Optimize disposable metadata transfer logic .

spring-cloud-starter-tencent-metadata-transfer/src/main/java/com/tencent/cloud/metadata/core/DecodeTransferMetadataReactiveFilter.java

@@ -97,5 +97,4 @@ public class DecodeTransferMetadataReactiveFilter implements WebFilter, Ordered
 
 		return JacksonUtils.deserialize2Map(customMetadataStr);
 	}
-
 }

spring-cloud-starter-tencent-metadata-transfer/src/main/java/com/tencent/cloud/metadata/core/EncodeTransferMedataFeignInterceptor.java

@@ -71,5 +71,4 @@ public class EncodeTransferMedataFeignInterceptor implements RequestInterceptor,
 			}
 		}
 	}
-
 }

spring-cloud-starter-tencent-metadata-transfer/src/main/java/com/tencent/cloud/metadata/core/EncodeTransferMetadataZuulFilter.java

@@ -79,5 +79,4 @@ public class EncodeTransferMetadataZuulFilter extends ZuulFilter {
 		}
 		return null;
 	}
-
 }

spring-cloud-tencent-commons/src/main/java/com/tencent/cloud/common/constant/MetadataConstant.java

@@ -26,6 +26,12 @@ import org.springframework.core.Ordered;
  */
 public final class MetadataConstant {
 
+	/**
+	 * Default Private Constructor.
+	 */
+	private MetadataConstant() {
+	}
+
 	/**
 	 * sct transitive header prefix.
 	 */
@@ -44,9 +50,11 @@ public final class MetadataConstant {
 	 */
 	public static final int POLARIS_TRANSITIVE_HEADER_PREFIX_LENGTH = POLARIS_TRANSITIVE_HEADER_PREFIX.length();
 
-	private MetadataConstant() {
+	/**
+	 * internal metadata disposable status key.
+	 */
+	public static final String INTERNAL_METADATA_DISPOSABLE = "internal-disposable-status";
 
-	}
 	/**
 	 * Order of filter, interceptor, ...
 	 */

spring-cloud-tencent-commons/src/main/java/com/tencent/cloud/common/metadata/MetadataContext.java

@@ -40,6 +40,7 @@ public class MetadataContext {
 	 * transitive context.
 	 */
 	public static final String FRAGMENT_TRANSITIVE = "transitive";
+
 	private static final Logger LOG = LoggerFactory.getLogger(MetadataContext.class);
 	/**
 	 * Namespace of local instance.

spring-cloud-tencent-commons/src/main/java/com/tencent/cloud/common/metadata/StaticMetadataManager.java

@@ -18,6 +18,7 @@
 
 package com.tencent.cloud.common.metadata;
 
+import java.io.UnsupportedEncodingException;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -32,6 +33,11 @@ import org.slf4j.LoggerFactory;
 
 import org.springframework.util.CollectionUtils;
 
+import static com.tencent.cloud.common.constant.ContextConstant.UTF_8;
+import static com.tencent.cloud.common.constant.MetadataConstant.INTERNAL_METADATA_DISPOSABLE;
+import static com.tencent.cloud.common.util.JacksonUtils.serialize2Json;
+import static java.net.URLEncoder.encode;
+
 /**
  * manage metadata from env/config file/custom spi.
  *
@@ -63,7 +69,7 @@ public class StaticMetadataManager {
 	private Map<String, String> configTransitiveMetadata;
 	private Map<String, String> customSPIMetadata;
 	private Map<String, String> customSPITransitiveMetadata;
-
+	private Map<String, String> disposableStatusMetadata;
 	private Map<String, String> mergedStaticMetadata;
 	private Map<String, String> mergedStaticTransitiveMetadata;
 	private String zone;
@@ -80,6 +86,8 @@ public class StaticMetadataManager {
 
 		parseLocationMetadata(metadataLocalProperties, instanceMetadataProvider);
 
+		parseDisposableStatusMetadata(metadataLocalProperties);
+
 		merge();
 
 		LOGGER.info("[SCT] Loaded static metadata info. {}", this);
@@ -164,6 +172,19 @@ public class StaticMetadataManager {
 		customSPITransitiveMetadata = Collections.unmodifiableMap(transitiveMetadata);
 	}
 
+	private void parseDisposableStatusMetadata(MetadataLocalProperties metadataLocalProperties) {
+		Map<String, String> allMetadata = metadataLocalProperties.getContent();
+		List<String> disposableKeys = metadataLocalProperties.getDisposable();
+
+		Map<String, String> result = new HashMap<>();
+		for (String key : disposableKeys) {
+			if (allMetadata.containsKey(key)) {
+				result.put(key, "false");
+			}
+		}
+		disposableStatusMetadata = Collections.unmodifiableMap(result);
+	}
+
 	private void merge() {
 		// the priority is : custom > env > config
 		Map<String, String> mergedMetadataResult = new HashMap<>();
@@ -181,6 +202,14 @@ public class StaticMetadataManager {
 		mergedTransitiveMetadataResult.putAll(envTransitiveMetadata);
 		mergedTransitiveMetadataResult.putAll(customSPITransitiveMetadata);
 
+		// append disposable status
+		try {
+			mergedTransitiveMetadataResult.put(INTERNAL_METADATA_DISPOSABLE, encode(serialize2Json(disposableStatusMetadata), UTF_8));
+		}
+		catch (UnsupportedEncodingException e) {
+			LOGGER.error("Runtime system does not support utf-8 coding.", e);
+		}
+
 		this.mergedStaticTransitiveMetadata = Collections.unmodifiableMap(mergedTransitiveMetadataResult);
 	}
 

spring-cloud-tencent-commons/src/main/java/com/tencent/cloud/common/spi/InstanceMetadataProvider.java

@@ -43,6 +43,13 @@ public interface InstanceMetadataProvider {
 		return Collections.emptySet();
 	}
 
+	/**
+	 * @return the keys of disposable metadata.
+	 */
+	default Set<String> getDisposableMetadataKeys() {
+		return Collections.emptySet();
+	}
+
 	/**
 	 * The region of current instance.
 	 *