Refactor

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/registry/AbstractSpringCloudRegistry.java

@@ -18,7 +18,6 @@ package org.springframework.cloud.alibaba.dubbo.registry;
 
 import org.apache.dubbo.common.Constants;
 import org.apache.dubbo.common.URL;
-import org.apache.dubbo.common.utils.UrlUtils;
 import org.apache.dubbo.registry.NotifyListener;
 import org.apache.dubbo.registry.RegistryFactory;
 import org.apache.dubbo.registry.support.FailbackRegistry;
@@ -29,20 +28,21 @@ import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.cloud.client.discovery.DiscoveryClient;
 
 import java.util.Collection;
-import java.util.Collections;
-import java.util.Iterator;
 import java.util.LinkedHashSet;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
 
+import static java.util.Collections.emptyList;
 import static java.util.Collections.singleton;
 import static org.apache.dubbo.common.Constants.PROVIDER_SIDE;
 import static org.apache.dubbo.common.Constants.SIDE_KEY;
 import static org.springframework.util.ObjectUtils.isEmpty;
+import static org.springframework.util.StringUtils.hasText;
 
 /**
  * Abstract Dubbo {@link RegistryFactory} uses Spring Cloud Service Registration abstraction, whose protocol is "spring-cloud"
@@ -144,13 +144,8 @@ public abstract class AbstractSpringCloudRegistry extends FailbackRegistry {
         }
     }
 
-    private void filterServiceNames(Collection<String> serviceNames) {
-        filter(serviceNames, new Filter<String>() {
-            @Override
-            public boolean accept(String serviceName) {
-                return supports(serviceName);
-            }
-        });
+    private Set<String> filterServiceNames(Collection<String> serviceNames) {
+        return new LinkedHashSet<>(filter(serviceNames, this::supports));
     }
 
     protected abstract boolean supports(String serviceName);
@@ -185,8 +180,7 @@ public abstract class AbstractSpringCloudRegistry extends FailbackRegistry {
      */
     protected Set<String> getServiceNamesForOps(URL url) {
         Set<String> serviceNames = getAllServiceNames();
-        filterServiceNames(serviceNames);
-        return serviceNames;
+        return filterServiceNames(serviceNames);
     }
 
     protected abstract String getServiceName(URL url);
@@ -206,7 +200,7 @@ public abstract class AbstractSpringCloudRegistry extends FailbackRegistry {
     }
 
     protected List<ServiceInstance> getServiceInstances(String serviceName) {
-        return discoveryClient.getInstances(serviceName);
+        return hasText(serviceName) ? discoveryClient.getInstances(serviceName) : emptyList();
     }
 
     private void subscribe(final URL url, final NotifyListener listener, final Collection<String> serviceNames) {
@@ -227,67 +221,9 @@ public abstract class AbstractSpringCloudRegistry extends FailbackRegistry {
      */
     protected abstract void notifySubscriber(URL url, NotifyListener listener, List<ServiceInstance> serviceInstances);
 
-    protected void filterHealthyInstances(Collection<ServiceInstance> instances) {
-        filter(instances, new Filter<ServiceInstance>() {
-            @Override
-            public boolean accept(ServiceInstance data) {
-                // TODO check the details of status
-//                return serviceRegistry.getStatus(new DubboRegistration(data)) != null;
-                return true;
-            }
-        });
-    }
-
-    protected List<URL> buildURLs(URL consumerURL, Collection<ServiceInstance> serviceInstances) {
-        if (serviceInstances.isEmpty()) {
-            return Collections.emptyList();
-        }
-        List<URL> urls = new LinkedList<URL>();
-        for (ServiceInstance serviceInstance : serviceInstances) {
-            URL url = buildURL(serviceInstance);
-            if (UrlUtils.isMatch(consumerURL, url)) {
-                urls.add(url);
-            }
-        }
-        return urls;
-    }
-
-    private URL buildURL(ServiceInstance serviceInstance) {
-        URL url = new URL(serviceInstance.getMetadata().get(Constants.PROTOCOL_KEY),
-                serviceInstance.getHost(),
-                serviceInstance.getPort(),
-                serviceInstance.getMetadata());
-        return url;
-    }
-
-    private <T> void filter(Collection<T> collection, Filter<T> filter) {
-        Iterator<T> iterator = collection.iterator();
-        while (iterator.hasNext()) {
-            T data = iterator.next();
-            if (!filter.accept(data)) { // remove if not accept
-                iterator.remove();
-            }
-        }
-    }
-
-    private static <T> T[] of(T... values) {
-        return values;
-    }
-
-    /**
-     * A filter
-     */
-    public interface Filter<T> {
-
-        /**
-         * Tests whether or not the specified data should be accepted.
-         *
-         * @param data The data to be tested
-         * @return <code>true</code> if and only if <code>data</code>
-         * should be accepted
-         */
-        boolean accept(T data);
-
+    protected <T> Collection<T> filter(Collection<T> collection, Predicate<T> filter) {
+        return collection.stream()
+                .filter(filter)
+                .collect(Collectors.toList());
     }
-
 }