1.简介:
引用自Dubbo官方文档简介:
http://dubbo.apache.org/zh-cn/docs/user/dependencies.html
随着互联网的发展，网站应用的规模不断扩大，常规的垂直应用架构已无法应对，分布式服务架构以及流动计算架构势在必行，亟需一个治理系统确保架构有条不紊的演进。
单一应用架构
当网站流量很小时，只需一个应用，将所有功能都部署在一起，以减少部署节点和成本。此时，用于简化增删改查工作量的数据访问框架(ORM)是关键。
垂直应用架构
当访问量逐渐增大，单一应用增加机器带来的加速度越来越小，将应用拆成互不相干的几个应用，以提升效率。此时，用于加速前端页面开发的Web框架(MVC)是关键。
分布式服务架构
当垂直应用越来越多，应用之间交互不可避免，将核心业务抽取出来，作为独立的服务，逐渐形成稳定的服务中心，使前端应用能更快速的响应多变的市场需求。此时，用于提高业务复用及整合的分布式服务框架(RPC)是关键。
流动计算架构
当服务越来越多，容量的评估，小服务资源的浪费等问题逐渐显现，此时需增加一个调度中心基于访问压力实时管理集群容量，提高集群利用率。此时，用于提高机器利用率的资源调度和治理中心(SOA)是关键。
2.Dubbo相关实例
dubbo的官方sample的github地址:
https://github.com/apache/dubbo-samples/tree/2.6.x
以下的demo参考以上官方文档而来：
pom.xm
4.0.0
com.home
dubbo-demo
1.0-SNAPSHOT
demo-api
pom
dubbo-demo Maven Webapp
http://www.example.com
UTF-8
1.7
1.7
2.7.3
org.apache.dubbo
dubbo
${dubbo.version}
spring
org.springframework
org.apache.curator
curator-framework
4.0.1
org.apache.curator
curator-framework
4.2.0
org.apache.curator
curator-recipes
4.2.0
org.springframework
spring-webmvc
4.3.14.RELEASE
com.101tec
zkclient
0.11
junit
junit
4.11
test
dubbo-demo
maven-clean-plugin
3.1.0
maven-resources-plugin
3.0.2
maven-compiler-plugin
3.8.0
maven-surefire-plugin
2.22.1
maven-war-plugin
3.2.2
maven-install-plugin
2.5.2
maven-deploy-plugin
2.8.2
EchoProvider:
package com.dubbo.service.provider;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import java.io.IOException;
public class EchoProvider {
public static void main(String[] args) throws IOException {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(
new String[]{"spring/echo-provider.xml"}
);
context.start();
System.in.read();
}
}EchoServiceImpl:
package com.dubbo.service.impl;
import com.alibaba.dubbo.rpc.RpcContext;
import com.dubbo.service.EchoService;
import java.text.SimpleDateFormat;
import java.util.Date;
public class EchoServiceImpl implements EchoService {
@Override
public String echo(String name) {
System.out.println("[" + new SimpleDateFormat("HH:mm:ss").format(new Date()) + "] Hello " +
name + ", request from consumer: " + RpcContext.getContext().getRemoteAddress());
return "Hello " + name + ", response from provider: " + RpcContext.getContext().getLocalAddress();
}
}echo-provider.xml:
EchoProvider:
package com.dubbo.service.provider;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import java.io.IOException;
public class EchoProvider {
public static void main(String[] args) throws IOException {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(
new String[]{"spring/echo-provider.xml"}
);
context.start();
System.in.read();
}
}
echo-consumer.xml
EchoConsumer
package com.dubbo.service.consumer;
import com.dubbo.service.EchoService;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class EchoConsumer {
public static void main(String[] args) {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(
new String[]{"spring/echo-consumer.xml"}
);
context.start();
EchoService echoService = (EchoService) context.getBean("echoService");
String status = echoService.echo("hello world");
System.out.println("echo:"+status);
}
}
主要需要先启动Zokeeper,然后启动提供方,之后启动消费方就可以收到相应的消息了.
3.使用注解形式,摘自官方文档
项目结构如下:
AnnotationAction
/*
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package annotation.action;
import annotation.AnnotationConstants;
import annotation.api.GreetingService;
import annotation.api.HelloService;
import org.apache.dubbo.config.annotation.Method;
import org.apache.dubbo.config.annotation.Reference;
import org.springframework.stereotype.Component;
@Component("annotationAction")
public class AnnotationAction {
@Reference(interfaceClass = HelloService.class, version = AnnotationConstants.VERSION)
private HelloService helloService;
@Reference(interfaceClass = GreetingService.class,
version = AnnotationConstants.VERSION,
methods = {@Method(name = "greeting", timeout = 250, retries = 1)})
private GreetingService greetingService;
public String doSayHello(String name) {
try {
return helloService.sayHello(name);
} catch (Exception e) {
e.printStackTrace();
return "Throw Exception";
}
}
public String doSayGoodbye(String name) {
try {
return helloService.sayGoodbye(name);
} catch (Exception e) {
e.printStackTrace();
return "Throw Exception";
}
}
public String doGreeting(String name) {
try {
return greetingService.greeting(name);
} catch (Exception e) {
e.printStackTrace();
return "Throw Exception";
}
}
public String replyGreeting(String name) {
try {
return greetingService.replyGreeting(name);
} catch (Exception e) {
e.printStackTrace();
return "Throw Exception";
}
}
}
GreetingService
package annotation.api;
import java.util.concurrent.CompletableFuture;
public interface GreetingService {
String greeting(String name);
default String replyGreeting(String name) {
return "Fine, " + name;
}
default CompletableFuture greeting(String name, byte signal) {
return CompletableFuture.completedFuture(greeting(name));
}
}
HelloService
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package annotation.api;
public interface HelloService {
String sayHello(String name);
default String sayGoodbye(String name) {
return "Goodbye, " + name;
}
}
AnnotationGreetingServiceImpl
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package annotation.impl;
import annotation.AnnotationConstants;
import annotation.api.GreetingService;
import org.apache.dubbo.config.annotation.Service;
@Service(version = AnnotationConstants.VERSION)
public class AnnotationGreetingServiceImpl implements GreetingService {
@Override
public String greeting(String name) {
System.out.println("provider received invoke of greeting: " + name);
sleepWhile();
return "Annotation, greeting " + name;
}
public String replyGreeting(String name) {
System.out.println("provider received invoke of replyGreeting: " + name);
sleepWhile();
return "Annotation, fine " + name;
}
private void sleepWhile() {
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
AnnotationHelloServiceImpl
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package annotation.impl;
import annotation.AnnotationConstants;
import annotation.api.HelloService;
import org.apache.dubbo.config.annotation.Method;
import org.apache.dubbo.config.annotation.Service;
@Service(version = AnnotationConstants.VERSION, methods = {@Method(name = "sayGoodbye", timeout = 250, retries = 0)})
public class AnnotationHelloServiceImpl implements HelloService {
@Override
public String sayHello(String name) {
System.out.println("provider received invoke of sayHello: " + name);
sleepWhile();
return "Annotation, hello " + name;
}
public String sayGoodbye(String name) {
System.out.println("provider received invoke of sayGoodbye: " + name);
sleepWhile();
return "Goodbye, " + name;
}
private void sleepWhile() {
try {
Thread.sleep(300);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
AnnotationConstants
package annotation;
public interface AnnotationConstants {
String VERSION = "1.0.0_annotation";
}
AnnotationConsumerBootstrap
/*
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package annotation;
import annotation.action.AnnotationAction;
import org.apache.dubbo.config.spring.context.annotation.EnableDubbo;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
public class AnnotationConsumerBootstrap {
public static void main(String[] args) {
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(ConsumerConfiguration.class);
context.start();
final AnnotationAction annotationAction = (AnnotationAction) context.getBean("annotationAction");
System.out.println("hello :" + annotationAction.doSayHello("world"));
System.out.println("goodbye :" + annotationAction.doSayGoodbye("world"));
System.out.println("greeting :" + annotationAction.doGreeting("world"));
System.out.println("reply :" + annotationAction.replyGreeting("world"));
}
@Configuration
@EnableDubbo(scanBasePackages = "annotation.action")
@PropertySource("classpath:/spring/dubbo-consumer.properties")
@ComponentScan(value = {"annotation.action"})
static public class ConsumerConfiguration {
}
}
AnnotationProviderBootstrap
/*
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package annotation;
import org.apache.dubbo.config.ProviderConfig;
import org.apache.dubbo.config.spring.context.annotation.EnableDubbo;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import java.util.concurrent.CountDownLatch;
public class AnnotationProviderBootstrap {
public static void main(String[] args) throws Exception {
new EmbeddedZooKeeper(2181, false).start();
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(ProviderConfiguration.class);
context.start();
System.out.println("dubbo service started.");
new CountDownLatch(1).await();
}
@Configuration
@EnableDubbo(scanBasePackages = "annotation.impl")
@PropertySource("classpath:/spring/dubbo-provider.properties")
static public class ProviderConfiguration {
@Bean
public ProviderConfig providerConfig() {
ProviderConfig providerConfig = new ProviderConfig();
providerConfig.setTimeout(1000);
return providerConfig;
}
}
}
EmbeddedZooKeeper:
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package annotation;
import org.apache.zookeeper.server.ServerConfig;
import org.apache.zookeeper.server.ZooKeeperServerMain;
import org.apache.zookeeper.server.quorum.QuorumPeerConfig;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.SmartLifecycle;
import org.springframework.util.ErrorHandler;
import org.springframework.util.SocketUtils;
import java.io.File;
import java.lang.reflect.Method;
import java.util.Properties;
import java.util.UUID;
/**
* from: https://github.com/spring-projects/spring-xd/blob/v1.3.1.RELEASE/spring-xd-dirt/src/main/java/org/springframework/xd/dirt/zookeeper/ZooKeeperUtils.java
*
* Helper class to start an embedded instance of standalone (non clustered) ZooKeeper.
*
* NOTE: at least an external standalone server (if not an ensemble) are recommended, even for
* {@link org.springframework.xd.dirt.server.singlenode.SingleNodeApplication}
*
* @author Patrick Peralta
* @author Mark Fisher
* @author David Turanski
*/
public class EmbeddedZooKeeper implements SmartLifecycle {
/**
* Logger.
*/
private static final Logger logger = LoggerFactory.getLogger(EmbeddedZooKeeper.class);
/**
* ZooKeeper client port. This will be determined dynamically upon startup.
*/
private final int clientPort;
/**
* Whether to auto-start. Default is true.
*/
private boolean autoStartup = true;
/**
* Lifecycle phase. Default is 0.
*/
private int phase = 0;
/**
* Thread for running the ZooKeeper server.
*/
private volatile Thread zkServerThread;
/**
* ZooKeeper server.
*/
private volatile ZooKeeperServerMain zkServer;
/**
* {@link ErrorHandler} to be invoked if an Exception is thrown from the ZooKeeper server thread.
*/
private ErrorHandler errorHandler;
private boolean daemon = true;
/**
* Construct an EmbeddedZooKeeper with a random port.
*/
public EmbeddedZooKeeper() {
clientPort = SocketUtils.findAvailableTcpPort();
}
/**
* Construct an EmbeddedZooKeeper with the provided port.
*
* @param clientPort port for ZooKeeper server to bind to
*/
public EmbeddedZooKeeper(int clientPort, boolean daemon) {
this.clientPort = clientPort;
this.daemon = daemon;
}
/**
* Returns the port that clients should use to connect to this embedded server.
*
* @return dynamically determined client port
*/
public int getClientPort() {
return this.clientPort;
}
/**
* Specify whether to start automatically. Default is true.
*
* @param autoStartup whether to start automatically
*/
public void setAutoStartup(boolean autoStartup) {
this.autoStartup = autoStartup;
}
/**
* {@inheritDoc}
*/
@Override
public boolean isAutoStartup() {
return this.autoStartup;
}
/**
* Specify the lifecycle phase for the embedded server.
*
* @param phase the lifecycle phase
*/
public void setPhase(int phase) {
this.phase = phase;
}
/**
* {@inheritDoc}
*/
@Override
public int getPhase() {
return this.phase;
}
/**
* {@inheritDoc}
*/
@Override
public boolean isRunning() {
return (zkServerThread != null);
}
/**
* Start the ZooKeeper server in a background thread.
*
* Register an error handler via {@link #setErrorHandler} in order to handle
* any exceptions thrown during startup or execution.
*/
@Override
public synchronized void start() {
if (zkServerThread == null) {
zkServerThread = new Thread(new ServerRunnable(), "ZooKeeper Server Starter");
zkServerThread.setDaemon(daemon);
zkServerThread.start();
}
}
/**
* Shutdown the ZooKeeper server.
*/
@Override
public synchronized void stop() {
if (zkServerThread != null) {
// The shutdown method is protected...thus this hack to invoke it.
// This will log an exception on shutdown; see
// https://issues.apache.org/jira/browse/ZOOKEEPER-1873 for details.
try {
Method shutdown = ZooKeeperServerMain.class.getDeclaredMethod("shutdown");
shutdown.setAccessible(true);
shutdown.invoke(zkServer);
} catch (Exception e) {
throw new RuntimeException(e);
}
// It is expected that the thread will exit after
// the server is shutdown; this will block until
// the shutdown is complete.
try {
zkServerThread.join(5000);
zkServerThread = null;
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
logger.warn("Interrupted while waiting for embedded ZooKeeper to exit");
// abandoning zk thread
zkServerThread = null;
}
}
}
/**
* Stop the server if running and invoke the callback when complete.
*/
@Override
public void stop(Runnable callback) {
stop();
callback.run();
}
/**
* Provide an {@link ErrorHandler} to be invoked if an Exception is thrown from the ZooKeeper server thread. If none
* is provided, only error-level logging will occur.
*
* @param errorHandler the {@link ErrorHandler} to be invoked
*/
public void setErrorHandler(ErrorHandler errorHandler) {
this.errorHandler = errorHandler;
}
/**
* Runnable implementation that starts the ZooKeeper server.
*/
private class ServerRunnable implements Runnable {
@Override
public void run() {
try {
Properties properties = new Properties();
File file = new File(System.getProperty("java.io.tmpdir")
+ File.separator + UUID.randomUUID());
file.deleteOnExit();
properties.setProperty("dataDir", file.getAbsolutePath());
properties.setProperty("clientPort", String.valueOf(clientPort));
QuorumPeerConfig quorumPeerConfig = new QuorumPeerConfig();
quorumPeerConfig.parseProperties(properties);
zkServer = new ZooKeeperServerMain();
ServerConfig configuration = new ServerConfig();
configuration.readFrom(quorumPeerConfig);
zkServer.runFromConfig(configuration);
} catch (Exception e) {
if (errorHandler != null) {
errorHandler.handleError(e);
} else {
logger.error("Exception running embedded ZooKeeper", e);
}
}
}
}
}
dubbo-consumer.properties
dubbo.application.name=samples-annotation-consumer
dubbo.registry.address=zookeeper://${zookeeper.address:127.0.0.1}:2181
dubbo.consumer.timeout=1000
dubbo-provider.properties
dubbo.application.name=samples-annotation-provider
dubbo.registry.address=zookeeper://${zookeeper.address:127.0.0.1}:2181
dubbo.protocol.name=dubbo
dubbo.protocol.port=20880log4j.properties
#
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
#
###set log levels###
log4j.rootLogger=info, stdout
###output to the console###
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{dd/MM/yy hh:mm:ss:sss z}] %t %5p %c{2}: %m%n