BAEL-1270 intro to dubbo (#3109)

* BAEL-1270 intro to dubbo

* BAEL-1270: add cluster and load-balancing tests

* BAEL-1270 exclude *LiveTest

* BAEL-1270 using call() instead of run() in executorService.submit()

dubbo/src/test/java/com/baeldung/dubbo/APIConfigurationLiveTest.java

@@ -0,0 +1,57 @@
+package com.baeldung.dubbo;
+
+import com.alibaba.dubbo.config.ApplicationConfig;
+import com.alibaba.dubbo.config.ReferenceConfig;
+import com.alibaba.dubbo.config.RegistryConfig;
+import com.alibaba.dubbo.config.ServiceConfig;
+import com.baeldung.dubbo.remote.GreetingsService;
+import com.baeldung.dubbo.remote.GreetingsServiceImpl;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author aiet
+ */
+public class APIConfigurationLiveTest {
+
+    @Before
+    public void initProvider() {
+        ApplicationConfig application = new ApplicationConfig();
+        application.setName("demo-provider");
+        application.setVersion("1.0");
+
+        RegistryConfig registryConfig = new RegistryConfig();
+        registryConfig.setAddress("multicast://224.1.1.1:9090");
+
+        ServiceConfig<GreetingsService> service = new ServiceConfig<>();
+        service.setApplication(application);
+        service.setRegistry(registryConfig);
+        service.setInterface(GreetingsService.class);
+        service.setRef(new GreetingsServiceImpl());
+
+        service.export();
+    }
+
+    @Test
+    public void givenProviderConsumer_whenSayHi_thenGotResponse() {
+        ApplicationConfig application = new ApplicationConfig();
+        application.setName("demo-consumer");
+        application.setVersion("1.0");
+
+        RegistryConfig registryConfig = new RegistryConfig();
+        registryConfig.setAddress("multicast://224.1.1.1:9090");
+
+        ReferenceConfig<GreetingsService> reference = new ReferenceConfig<>();
+        reference.setApplication(application);
+        reference.setRegistry(registryConfig);
+        reference.setInterface(GreetingsService.class);
+
+        GreetingsService greetingsService = reference.get();
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        assertEquals("hi, baeldung", hiMessage);
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/ClusterDynamicLoadBalanceLiveTest.java

@@ -0,0 +1,70 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.OptionalDouble;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author aiet
+ */
+public class ClusterDynamicLoadBalanceLiveTest {
+
+    private ExecutorService executorService;
+
+    @Before
+    public void initRemote() {
+        executorService = Executors.newFixedThreadPool(2);
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext remoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-default.xml");
+            remoteContext.start();
+        });
+        executorService.submit(() -> {
+            SECONDS.sleep(2);
+            ClassPathXmlApplicationContext backupRemoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-special.xml");
+            backupRemoteContext.start();
+            return null;
+        });
+    }
+
+    @Test
+    public void givenProviderCluster_whenConsumerSaysHi_thenResponseBalanced() throws InterruptedException {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("cluster/consumer-app-lb.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        List<Long> elapseList = new ArrayList<>(6);
+        for (int i = 0; i < 6; i++) {
+            long current = System.currentTimeMillis();
+            String hiMessage = greetingsService.sayHi("baeldung");
+            assertNotNull(hiMessage);
+            elapseList.add(System.currentTimeMillis() - current);
+            SECONDS.sleep(1);
+        }
+
+        OptionalDouble avgElapse = elapseList
+          .stream()
+          .mapToLong(e -> e)
+          .average();
+        assertTrue(avgElapse.isPresent());
+        assertTrue(avgElapse.getAsDouble() > 1666.0);
+
+    }
+
+    @After
+    public void destroy() {
+        executorService.shutdown();
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/ClusterFailoverLiveTest.java

@@ -0,0 +1,52 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * @author aiet
+ */
+public class ClusterFailoverLiveTest {
+
+    private ExecutorService executorService;
+
+    @Before
+    public void initRemote() {
+        executorService = Executors.newFixedThreadPool(2);
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext backupRemoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-special.xml");
+            backupRemoteContext.start();
+        });
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext remoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-failover.xml");
+            remoteContext.start();
+        });
+
+    }
+
+    @Test
+    public void givenProviderCluster_whenConsumerSaysHi_thenGotFailoverResponse() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("cluster/consumer-app-failtest.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        assertNotNull(hiMessage);
+        assertEquals("hi, failover baeldung", hiMessage);
+    }
+
+    @After
+    public void destroy() {
+        executorService.shutdown();
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/ClusterFailsafeLiveTest.java

@@ -0,0 +1,47 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+/**
+ * @author aiet
+ */
+public class ClusterFailsafeLiveTest {
+
+    private ExecutorService executorService;
+
+    @Before
+    public void initRemote() {
+        executorService = Executors.newFixedThreadPool(1);
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext remoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-special-failsafe.xml");
+            remoteContext.start();
+        });
+    }
+
+    @Test
+    public void givenProviderCluster_whenConsumerSaysHi_thenGotFailsafeResponse() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("cluster/consumer-app-failtest.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        assertNull(hiMessage);
+    }
+
+    @After
+    public void destroy() {
+        executorService.shutdown();
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/ClusterLoadBalanceLiveTest.java

@@ -0,0 +1,66 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.OptionalDouble;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author aiet
+ */
+public class ClusterLoadBalanceLiveTest {
+
+    private ExecutorService executorService;
+
+    @Before
+    public void initRemote() {
+        executorService = Executors.newFixedThreadPool(2);
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext remoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-default.xml");
+            remoteContext.start();
+        });
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext backupRemoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-special.xml");
+            backupRemoteContext.start();
+        });
+    }
+
+    @Test
+    public void givenProviderCluster_whenConsumerSaysHi_thenResponseBalanced() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("cluster/consumer-app-lb.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        List<Long> elapseList = new ArrayList<>(6);
+        for (int i = 0; i < 6; i++) {
+            long current = System.currentTimeMillis();
+            String hiMessage = greetingsService.sayHi("baeldung");
+            assertNotNull(hiMessage);
+            elapseList.add(System.currentTimeMillis() - current);
+        }
+
+        OptionalDouble avgElapse = elapseList
+          .stream()
+          .mapToLong(e -> e)
+          .average();
+        assertTrue(avgElapse.isPresent());
+        System.out.println(avgElapse.getAsDouble());
+        assertTrue(avgElapse.getAsDouble() > 2500.0);
+
+    }
+
+    @After
+    public void destroy() {
+        executorService.shutdown();
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/MulticastRegistryLiveTest.java

@@ -0,0 +1,36 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * @author aiet
+ */
+public class MulticastRegistryLiveTest {
+
+    private ClassPathXmlApplicationContext remoteContext;
+
+    @Before
+    public void initRemote() {
+        remoteContext = new ClassPathXmlApplicationContext("multicast/provider-app.xml");
+        remoteContext.start();
+    }
+
+    @Test
+    public void givenProvider_whenConsumerSaysHi_thenGotResponse() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("multicast/consumer-app.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        assertNotNull(hiMessage);
+        assertEquals("hi, baeldung", hiMessage);
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/ResultCacheLiveTest.java

@@ -0,0 +1,47 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author aiet
+ */
+public class ResultCacheLiveTest {
+
+    private ClassPathXmlApplicationContext remoteContext;
+
+    @Before
+    public void initRemote() {
+        remoteContext = new ClassPathXmlApplicationContext("multicast/provider-app-special.xml");
+        remoteContext.start();
+    }
+
+    @Test
+    public void givenProvider_whenConsumerSaysHi_thenGotResponse() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("multicast/consumer-app.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+
+        long before = System.currentTimeMillis();
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        long timeElapsed = System.currentTimeMillis() - before;
+        assertTrue(timeElapsed > 5000);
+        assertNotNull(hiMessage);
+        assertEquals("hi, baeldung", hiMessage);
+
+
+        before = System.currentTimeMillis();
+        hiMessage = greetingsService.sayHi("baeldung");
+        timeElapsed = System.currentTimeMillis() - before;
+        assertTrue(timeElapsed < 1000);
+        assertNotNull(hiMessage);
+        assertEquals("hi, baeldung", hiMessage);
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/SimpleRegistryLiveTest.java

@@ -0,0 +1,39 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * @author aiet
+ */
+public class SimpleRegistryLiveTest {
+
+    private ClassPathXmlApplicationContext remoteContext;
+    private ClassPathXmlApplicationContext registryContext;
+
+    @Before
+    public void initRemote() {
+        registryContext = new ClassPathXmlApplicationContext("simple/registry.xml");
+        registryContext.start();
+
+        remoteContext = new ClassPathXmlApplicationContext("simple/provider-app.xml");
+        remoteContext.start();
+    }
+
+    @Test
+    public void givenProvider_whenConsumerSaysHi_thenGotResponse() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("simple/consumer-app.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        assertNotNull(hiMessage);
+        assertEquals("hi, baeldung", hiMessage);
+    }
+
+}

dubbo/src/test/resources/cluster/consumer-app-failtest.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-consumer" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- remote service proxy, acting like a local bean while invoking -->
+    <dubbo:reference interface="com.baeldung.dubbo.remote.GreetingsService" id="greetingsService" retries="2" timeout="2000" />
+
+</beans>

dubbo/src/test/resources/cluster/consumer-app-lb.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-consumer" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- remote service proxy, acting like a local bean while invoking -->
+    <dubbo:reference interface="com.baeldung.dubbo.remote.GreetingsService" id="greetingsService" retries="2" timeout="10000" loadbalance="roundrobin" />
+
+</beans>

dubbo/src/test/resources/cluster/provider-app-default.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20880"/>
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService" cluster="failsafe"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceImpl"/>
+
+</beans>

dubbo/src/test/resources/cluster/provider-app-failover.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20880"/>
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService" cluster="failover"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsFailoverServiceImpl"/>
+
+</beans>

dubbo/src/test/resources/cluster/provider-app-special-failsafe.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20881" />
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService" cluster="failsafe"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceSpecialImpl"/>
+
+</beans>

dubbo/src/test/resources/cluster/provider-app-special.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20881" />
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService" cluster="failover"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceSpecialImpl"/>
+
+</beans>

dubbo/src/test/resources/log4j.properties

@@ -0,0 +1,6 @@
+log4j.rootLogger=INFO, stdout
+
+log4j.appender.stdout=org.apache.log4j.ConsoleAppender
+log4j.appender.stdout.Target=System.out
+log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
+log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

dubbo/src/test/resources/multicast/consumer-app.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-consumer" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="multicast://224.1.1.1:9090"/>
+
+    <!-- remote service proxy, acting like a local bean while invoking -->
+    <dubbo:reference interface="com.baeldung.dubbo.remote.GreetingsService" id="greetingsService" cache="lru" />
+
+</beans>

dubbo/src/test/resources/multicast/provider-app-special.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="multicast://224.1.1.1:9090"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20881" />
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceSpecialImpl"/>
+
+</beans>

dubbo/src/test/resources/multicast/provider-app.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="multicast://224.1.1.1:9090"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20880"/>
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceImpl"/>
+
+</beans>

dubbo/src/test/resources/simple/consumer-app.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-consumer" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="127.0.0.1:9090"/>
+
+    <!-- remote service proxy, acting like a local bean while invoking -->
+    <dubbo:reference interface="com.baeldung.dubbo.remote.GreetingsService" id="greetingsService" cluster="failover" retries="2"/>
+
+</beans>

dubbo/src/test/resources/simple/provider-app.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="127.0.0.1:9090"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20880"/>
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceImpl"/>
+
+</beans>

dubbo/src/test/resources/simple/registry.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <dubbo:application name="simple-registry" />
+
+    <dubbo:protocol port="9090" />
+
+    <dubbo:service interface="com.alibaba.dubbo.registry.RegistryService" ref="registryService" registry="N/A" ondisconnect="disconnect">
+        <dubbo:method name="subscribe"><dubbo:argument index="1" callback="true" /></dubbo:method>
+        <dubbo:method name="unsubscribe"><dubbo:argument index="1" callback="true" /></dubbo:method>
+    </dubbo:service>
+
+    <bean id="registryService" class="com.alibaba.dubbo.registry.simple.SimpleRegistryService" />
+
+</beans>