[ISSUE 2827]: hotfix config dump

.travis.yml

@@ -29,7 +29,7 @@ before_install:
 script:
   - mvn -B clean package apache-rat:check findbugs:findbugs -Dmaven.test.skip=true
   - mvn -Prelease-nacos -Dmaven.test.skip=true clean install -U
-  - mvn clean install -Pit-test
+  - mvn clean package -Pit-test
 after_success:
   - mvn clean package -Pit-test
   - mvn sonar:sonar -Psonar-apache

client/src/test/java/com/alibaba/nacos/client/ConfigTest.java

@@ -18,19 +18,46 @@
 
 package com.alibaba.nacos.client;
 
+import com.alibaba.nacos.api.NacosFactory;
+import com.alibaba.nacos.api.PropertyKeyConst;
 import com.alibaba.nacos.api.config.ConfigService;
+import com.alibaba.nacos.common.utils.ThreadUtils;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Test;
+
+import java.util.Properties;
 
 /**
  * @author <a href="mailto:liaochuntao@live.com">liaochuntao</a>
  */
+@Ignore
 public class ConfigTest {
 
-	private ConfigService config7;
-	private ConfigService config8;
-	private ConfigService config9;
+	private ConfigService configService;
+
+	@Before
+	public void before() throws Exception {
+		Properties properties = new Properties();
+		properties.setProperty(PropertyKeyConst.NAMESPACE, "bebf0150-e1ea-47e2-81fe-6814caf2b952");
+		properties.setProperty(PropertyKeyConst.SERVER_ADDR, "127.0.0.1:8848");
+		properties.setProperty(PropertyKeyConst.USERNAME, "chuntaojun");
+		properties.setProperty(PropertyKeyConst.PASSWORD, "1017");
+		configService = NacosFactory.createConfigService(properties);
+	}
 
-	public void test() {
+	@Test
+	public void test() throws Exception {
+		final String dataId = "lessspring";
+		final String group = "lessspring";
+		final String content = "lessspring-" + System.currentTimeMillis();
+		boolean result = configService.publishConfig(dataId, group, content);
+		Assert.assertTrue(result);
 
+		ThreadUtils.sleep(10_000);
+		String response = configService.getConfig(dataId, group, 5000);
+		System.out.println(response);
 	}
 
 }

common/src/main/java/com/alibaba/nacos/common/utils/Observable.java

@@ -16,6 +16,7 @@
 
 package com.alibaba.nacos.common.utils;
 
+import java.util.Objects;
 import java.util.Set;
 
 /**
@@ -25,6 +26,8 @@ public class Observable {
 
 	private transient boolean changed = false;
 	private transient Set<Observer> obs = new ConcurrentHashSet<>();
+	private volatile int observerCnt = 0;
+	private boolean alreadyAddObserver = false;
 
 	/**
 	 * Adds an observer to the set of observers for this object, provided
@@ -35,20 +38,24 @@ public class Observable {
 	 * @param   o   an observer to be added.
 	 * @throws NullPointerException   if the parameter o is null.
 	 */
-	public void addObserver(Observer o) {
-		if (o == null) {
-			throw new NullPointerException();
-		}
+	public synchronized void addObserver(Observer o) {
+		Objects.requireNonNull(o, "Observer");
 		obs.add(o);
+		observerCnt ++;
+		if (!alreadyAddObserver) {
+			notifyAll();
+		}
+		alreadyAddObserver = true;
 	}
 
 	/**
 	 * Deletes an observer from the set of observers of this object.
 	 * Passing {@code null} to this method will have no effect.
 	 * @param   o   the observer to be deleted.
 	 */
-	public void deleteObserver(Observer o) {
+	public synchronized void deleteObserver(Observer o) {
 		obs.remove(o);
+		observerCnt --;
 	}
 
 	/**
@@ -96,6 +103,9 @@ public void notifyObservers(Object arg) {
 				return;
 			}
 			clearChanged();
+			if (!alreadyAddObserver) {
+				ThreadUtils.objectWait(this);
+			}
 		}
 
 		for (Observer observer : obs) {
@@ -150,8 +160,8 @@ public synchronized boolean hasChanged() {
 	 * @return  the number of observers of this object.
 	 */
 	public int countObservers() {
-		return obs.size();
+		return observerCnt;
 	}
 
 
-}
+}

common/src/main/java/com/alibaba/nacos/common/utils/ThreadUtils.java

@@ -24,6 +24,14 @@
  */
 public final class ThreadUtils {
 
+    public static void objectWait(Object object) {
+        try {
+            object.wait();
+        } catch (InterruptedException ignore) {
+            Thread.interrupted();
+        }
+    }
+
     public static void sleep(long millis) {
         try {
             Thread.sleep(millis);
@@ -49,7 +57,8 @@ public static void latchAwait(CountDownLatch latch, long time, TimeUnit unit) {
     }
 
     /**
-     * 通过内核数，算出合适的线程数；1.5-2倍cpu内核数
+     * Through the number of cores, calculate the appropriate number of threads;
+     * 1.5-2 times the number of CPU cores
      *
      * @return thread count
      */