5、zookeeper的java -Curator（服务注册与发现）
Zookeeper系列文章目录
1、zookeeper3.7.1安装与验证
2、zookeeper基本操作及应用示例（shell、java api、应用场景示例）
3、zookeeper的选举----经验证符合事实，网上很多都是错误的
4、zookeeper的java三种客户端介绍-Curator（crud、事务操作、监听、分布式计数器、分布式锁）
5、zookeeper的java -Curator（服务注册与发现）
目录
本文介绍使用zookeeper的Curator类库实现服务的注册与发现。
该示例会涉及到本专栏下的其他文章，比如：4、zookeeper的java三种客户端介绍-Curator（crud、事务操作、监听、分布式计数器、分布式锁）
等文章，都是在该专栏下的。
一、知识介绍
Curator Service Discovery它对此抽象出了ServiceInstance、ServiceProvider、ServiceDiscovery三个接口，通过它我们可以很轻易的实现Service Discovery。
1、ServiceInstance
Curator中使用ServiceInstance作为一个服务实例，ServiceInstances具有名称，ID，地址，端口和/或ssl端口以及可选的payload(用户定义）。ServiceInstances以下列方式序列化并存储在ZooKeeper中：
2、ServiceProvider
ServiceProvider是主要的抽象类。它封装了发现服务为特定的命名服务和提供者策略。提供者策略方案是从一组给定的服务实例选择一个实例。有三个捆绑策略:轮询调度、随机和粘性(总是选择相同的一个)。
ServiceProviders是使用ServiceProviderBuilder分配的。消费者可以从ServiceDiscovery获取ServiceProviderBuilder。ServiceProviderBuilder允许设置服务名称和其他几个可选值。
必须通过调用start()来启动ServiceProvider 。完成后，应该调用close()。
ServiceProvider中有以下两个重要方法：
/** 获取一个服务实例 */
public ServiceInstance<T> getInstance() throws Exception;
/** 获取所有的服务实例 */
public Collection<ServiceInstance<T>> getAllInstances() throws Exception;
在使用curator 2.x(ZooKeep3.4.x)时，服务提供者对象必须由应用程序缓存并重用。因为服务提供者添加的内部NamespaceWatcher对象无法在ZooKeep3.4.x中删除，所以为每个对相同服务的调用创建一个新的服务提供者最终将耗尽JVM的内存。
3、ServiceDiscovery
为了创建ServiceProvider,必须有一个ServiceDiscovery。它是由一个ServiceDiscoveryBuilder创建。开始必须调用start()方法。当使用完成应该调用close()方法。
如果特定实例有I/O错误，等等。您应该调用ServiceProvider.NoteError()，并传入实例。ServiceProvider将临时将有错误的实例视为“关闭”。实例的阈值和超时是通过DownInstancePolicy设置的，该策略可以传递给ServiceProviderBuilder(注意：如果没有指定默认DownInstancePolicy，则使用默认DownInstancePolicy)。
对于更精细的控制，您可以使用以下方法：
1）、注册/注销服务
通常，将应用程序的服务描述符传递给ServiceDiscovery构造函数，它将自动注册/注销服务。但是，如果需要手动执行此操作，请使用以下方法：
/** 注册服务 */
public void registerService(ServiceInstance<T> service) throws Exception;
/** 注销服务 */
public void unregisterService(ServiceInstance<T> service) throws Exception;
2）、查询服务
您可以查询所有服务名称、特定服务的所有实例或单个服务实例。
/** 查询所有服务名称 */
public Collection<String> queryForNames() throws Exception;
/** 查询特定服务的所有实例 */
public Collection<ServiceInstance<T>> queryForInstances(String name) throws Exception;
/** 查询单个服务实例 */
public ServiceInstance<T> queryForInstance(String name, String id) throws Exception;
3）、服务缓存
上述每个查询方法都直接调用ZooKeeper。
如果经常查询服务，还可以使用ServiceCache。它在内存中缓存特定服务的实例列表。它使用Watcher监听使列表保持最新。
可以通过ServiceDiscovery.serviceCacheBuilder()返回的构建器分配ServiceCache 。
通过调用start()启动ServiceCache对象，完成后，应调用close()。
然后可以通过调用以下内容获取服务的当前已知实例列表：
/** 获取缓存服务列表 */
public List<ServiceInstance<T>> getInstances();
ServiceCache支持在Watcher更新实例列表时收到通知的侦听器：
/**
* Listener for changes to a service cache
*/
public interface ServiceCacheListener extends ConnectionStateListener {
/**
* Called when the cache has changed (instances added/deleted, etc.)
*/
public void cacheChanged();
}
二、示例1
1、pom.xml
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.22</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
<version>5.3.0</version>
</dependency>
<!--https://mvnrepository.com/artifact/org.apache.curator/curator-client -->
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-client</artifactId>
<version>5.3.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.curator/curator-x-discovery -->
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-x-discovery</artifactId>
<version>5.3.0</version>
</dependency>
2、ServiceInstance
该serviceInstance是经过扩展后的，也可以不需要那么多的属性。
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import lombok.Data;
/**
* @author alanchan
*
*/
@Data
public class InstanceDetails {
public static final String ROOT_PATH = "/service";
//该服务拥有哪些方法
public Map<String, Service> services = new HashMap<>();
//服务描述
private String serviceDescription;
public InstanceDetails() {
this.serviceDescription = "";
}
public InstanceDetails(String serviceDescription) {
this.serviceDescription = serviceDescription;
}
@Data
public static class Service {
//方法名称
private String methodName;
//方法描述
private String description;
//方法所需要的参数列表
private List<String> params;
}
}
3、ServiceProvider及ServiceDiscovery
import java.io.Closeable;
import java.io.IOException;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.utils.CloseableUtils;
import org.apache.curator.x.discovery.ServiceDiscovery;
import org.apache.curator.x.discovery.ServiceDiscoveryBuilder;
import org.apache.curator.x.discovery.ServiceInstance;
import org.apache.curator.x.discovery.UriSpec;
import org.apache.curator.x.discovery.details.JsonInstanceSerializer;
/**
* @author alanchan
*
*/
public class ExampleServer implements Closeable {
private final ServiceDiscovery<InstanceDetails> serviceDiscovery;
private final ServiceInstance<InstanceDetails> serviceInstance;
public ExampleServer(CuratorFramework client, String path, String serviceName, String description)
throws Exception {
UriSpec uriSpec = new UriSpec("{scheme}://foo.com:{port}");
serviceInstance = ServiceInstance
.<InstanceDetails>builder()
.name(serviceName)
.payload(new InstanceDetails(description))
.port((int) (65535 * Math.random()))
.uriSpec(uriSpec)
.build();
JsonInstanceSerializer<InstanceDetails> serializer = new JsonInstanceSerializer<InstanceDetails>(
InstanceDetails.class);
serviceDiscovery = ServiceDiscoveryBuilder
.builder(InstanceDetails.class)
.client(client)
.basePath(path)
.serializer(serializer)
.thisInstance(serviceInstance)
.build();
}
public ServiceInstance<InstanceDetails> getServiceInstance() {
return serviceInstance;
}
public void start() throws Exception {
serviceDiscovery.start();
}
@Override
public void close() throws IOException {
CloseableUtils.closeQuietly(serviceDiscovery);
}
}
4、注册服务的添加、删除、查询
本示例是通过键盘输入方式进行服务的注册、删除、查询操作。
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.curator.framework.CuratorFramework;
//import org.apache.curator.shaded.com.google.common.base.Predicate;
//import org.apache.curator.shaded.com.google.common.collect.Iterables;
//import org.apache.curator.shaded.com.google.common.collect.Lists;
//import org.apache.curator.shaded.com.google.common.collect.Maps;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import org.apache.curator.utils.CloseableUtils;
import org.apache.curator.x.discovery.ServiceDiscovery;
import org.apache.curator.x.discovery.ServiceDiscoveryBuilder;
import org.apache.curator.x.discovery.ServiceInstance;
import org.apache.curator.x.discovery.ServiceProvider;
import org.apache.curator.x.discovery.details.JsonInstanceSerializer;
import org.apache.curator.x.discovery.strategies.RandomStrategy;
import org.apache.zookeeper.KeeperException;
import org.zookeeper_curator.App;
import org.zookeeper_curator.Constant;
/**
* @author alanchan
*
*/
public class ConsumerExampleServer {
private static final String PATH = "/discovery/example";
public static void main(String[] args) throws Exception {
CuratorFramework client = null;
ServiceDiscovery<InstanceDetails> serviceDiscovery = null;
Map<String, ServiceProvider<InstanceDetails>> providers = Maps.newHashMap();
try {
client = App.createWithOptions(Constant.zkServerAddress, Constant.retryPolicy, Constant.CONNECTION_TIMEOUT,
Constant.SESSION_TIMEOUT);
client.start();
JsonInstanceSerializer<InstanceDetails> serializer = new JsonInstanceSerializer<InstanceDetails>(
InstanceDetails.class);
serviceDiscovery = ServiceDiscoveryBuilder.builder(InstanceDetails.class).client(client).basePath(PATH)
.serializer(serializer).build();
serviceDiscovery.start();
// 服务列表
// List<ExampleServer> servers = Lists.newArrayList();
// testingServiceName 添加成功
// 1 type(s)
// testingServiceName
// desc: http://foo.com:57438
// addInstance(String serviceName, String description, CuratorFramework client,List<ExampleServer> servers)
// addInstance("testingServiceName","desc", client, servers);
//
// deleteInstance(String serviceName, List<ExampleServer> servers)
// deleteInstance("testingServiceName", servers);
// listRandomInstance(String serviceName, ServiceDiscovery<InstanceDetails>
// serviceDiscovery,Map<String, ServiceProvider<InstanceDetails>> providers)
// listRandomInstance("testingServiceName", serviceDiscovery, providers);
// listInstances(ServiceDiscovery<InstanceDetails> serviceDiscovery)
// listInstances(serviceDiscovery);
// 采用命令方式操作几个方法
command(serviceDiscovery, providers, client);
} finally {
for (ServiceProvider<InstanceDetails> cache : providers.values()) {
CloseableUtils.closeQuietly(cache);
}
CloseableUtils.closeQuietly(serviceDiscovery);
CloseableUtils.closeQuietly(client);
}
}
private static void command(ServiceDiscovery<InstanceDetails> serviceDiscovery,
Map<String, ServiceProvider<InstanceDetails>> providers, CuratorFramework client) throws Exception {
List<ExampleServer> servers = Lists.newArrayList();
try {
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
boolean done = false;
while (!done) {
System.out.print("> ");
String line = in.readLine();
if (line == null) {
break;
}
String command = line.trim();
String[] parts = command.split("\\s");
if (parts.length == 0) {
continue;
}
String operation = parts[0];
String args[] = Arrays.copyOfRange(parts, 1, parts.length);
if (operation.equalsIgnoreCase("q") || operation.equalsIgnoreCase("quit")) {
done = true;
} else if (operation.equals("add")) {
addInstance(args[0], args[1], client, servers);
} else if (operation.equals("delete")) {
deleteInstance(args[0], servers);
} else if (operation.equals("random")) {
listRandomInstance(args[0], serviceDiscovery, providers);
} else if (operation.equals("list")) {
listInstances(serviceDiscovery);
}
}
} finally {
for (ExampleServer server : servers) {
CloseableUtils.closeQuietly(server);
}
}
}
// 删除服务
private static void deleteInstance(String serviceName, List<ExampleServer> servers) {
ExampleServer server = Iterables.find(servers, new Predicate<ExampleServer>() {
@Override
public boolean apply(ExampleServer server) {
return server.getServiceInstance().getName().endsWith(serviceName);
}
}, null);
if (server == null) {
System.err.println("没有查到服务名称为: " + serviceName + "的服务");
return;
}
servers.remove(server);
CloseableUtils.closeQuietly(server);
System.out.println("移除服务名称为：: " + serviceName + "的服务");
}
// 查看服务
private static void listRandomInstance(String serviceName, ServiceDiscovery<InstanceDetails> serviceDiscovery,
Map<String, ServiceProvider<InstanceDetails>> providers) throws Exception {
ServiceProvider<InstanceDetails> provider = providers.get(serviceName);
if (provider == null) {
provider = serviceDiscovery.serviceProviderBuilder().serviceName(serviceName)
.providerStrategy(new RandomStrategy<InstanceDetails>()).build();
providers.put(serviceName, provider);
provider.start();
Thread.sleep(2500); // give the provider time to warm up - in a real application you wouldn't need
// to do this
}
ServiceInstance<InstanceDetails> instance = provider.getInstance();
if (instance == null) {
System.err.println("没有查到服务名称为: " + serviceName + "的服务");
} else {
System.out.println("\t" + instance.getPayload().getServiceDescription() + ": " + instance.buildUriSpec());
}
}
// 查看服务列表
private static void listInstances(ServiceDiscovery<InstanceDetails> serviceDiscovery) throws Exception {
try {
Collection<String> serviceNames = serviceDiscovery.queryForNames();
for (String serviceName : serviceNames) {
Collection<ServiceInstance<InstanceDetails>> instances = serviceDiscovery
.queryForInstances(serviceName);
System.out.println(serviceName);
for (ServiceInstance<InstanceDetails> instance : instances) {
System.out.println(
"\t" + instance.getPayload().getServiceDescription() + ": " + instance.buildUriSpec());
}
}
} catch (KeeperException.NoNodeException e) {
e.printStackTrace();
System.err.println("没有找到服务注册实例.");
} finally {
CloseableUtils.closeQuietly(serviceDiscovery);
}
}
// 添加服务
private static void addInstance(String serviceName, String description, CuratorFramework client,
List<ExampleServer> servers) throws Exception {
ExampleServer server = new ExampleServer(client, PATH, serviceName, description);
servers.add(server);
server.start();
System.out.println(serviceName + " 添加成功");
}
}
5、验证示例1
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.curator.framework.CuratorFramework;
//import org.apache.curator.shaded.com.google.common.base.Predicate;
//import org.apache.curator.shaded.com.google.common.collect.Iterables;
//import org.apache.curator.shaded.com.google.common.collect.Lists;
//import org.apache.curator.shaded.com.google.common.collect.Maps;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import org.apache.curator.utils.CloseableUtils;
import org.apache.curator.x.discovery.ServiceDiscovery;
import org.apache.curator.x.discovery.ServiceDiscoveryBuilder;
import org.apache.curator.x.discovery.ServiceInstance;
import org.apache.curator.x.discovery.ServiceProvider;
import org.apache.curator.x.discovery.details.JsonInstanceSerializer;
import org.apache.curator.x.discovery.strategies.RandomStrategy;
import org.apache.zookeeper.KeeperException;
import org.zookeeper_curator.App;
import org.zookeeper_curator.Constant;
public class Test {
private static final String PATH = "/discovery/example";
public static void main(String[] args) throws Exception {
CuratorFramework client = null;
ServiceDiscovery<InstanceDetails> serviceDiscovery = null;
Map<String, ServiceProvider<InstanceDetails>> providers = Maps.newHashMap();
try {
client = App.createWithOptions(Constant.zkServerAddress, Constant.retryPolicy, Constant.CONNECTION_TIMEOUT,
Constant.SESSION_TIMEOUT);
client.start();
JsonInstanceSerializer<InstanceDetails> serializer = new JsonInstanceSerializer<InstanceDetails>(
InstanceDetails.class);
serviceDiscovery = ServiceDiscoveryBuilder.builder(InstanceDetails.class).client(client).basePath(PATH)
.serializer(serializer).build();
serviceDiscovery.start();
processCommands(serviceDiscovery, providers, client);
} finally {
for (ServiceProvider<InstanceDetails> cache : providers.values()) {
CloseableUtils.closeQuietly(cache);
}
CloseableUtils.closeQuietly(serviceDiscovery);
CloseableUtils.closeQuietly(client);
}
}
private static void processCommands(ServiceDiscovery<InstanceDetails> serviceDiscovery,
Map<String, ServiceProvider<InstanceDetails>> providers, CuratorFramework client) throws Exception {
printHelp();
List<ExampleServer> servers = Lists.newArrayList();
try {
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
boolean done = false;
while (!done) {
System.out.print("> ");
String line = in.readLine();
if (line == null) {
break;
}
String command = line.trim();
String[] parts = command.split("\\s");
if (parts.length == 0) {
continue;
}
String operation = parts[0];
String args[] = Arrays.copyOfRange(parts, 1, parts.length);
if (operation.equalsIgnoreCase("help") || operation.equalsIgnoreCase("?")) {
printHelp();
} else if (operation.equalsIgnoreCase("q") || operation.equalsIgnoreCase("quit")) {
done = true;
} else if (operation.equals("add")) {
addInstance(args, client, command, servers);
} else if (operation.equals("delete")) {
deleteInstance(args, command, servers);
} else if (operation.equals("random")) {
listRandomInstance(args, serviceDiscovery, providers, command);
} else if (operation.equals("list")) {
listInstances(serviceDiscovery);
}
}
} finally {
for (ExampleServer server : servers) {
CloseableUtils.closeQuietly(server);
}
}
}
private static void deleteInstance(String[] args, String command, List<ExampleServer> servers) {
if (args.length != 1) {
System.err.println("syntax error (expected delete <name>): " + command);
return;
}
final String serviceName = args[0];
ExampleServer server = Iterables.find(servers, new Predicate<ExampleServer>() {
@Override
public boolean apply(ExampleServer server) {
return server.getServiceInstance().getName().endsWith(serviceName);
}
}, null);
if (server == null) {
System.err.println("No servers found named: " + serviceName);
return;
}
servers.remove(server);
CloseableUtils.closeQuietly(server);
System.out.println("Removed a random instance of: " + serviceName);
}
private static void listRandomInstance(String[] args, ServiceDiscovery<InstanceDetails> serviceDiscovery,
Map<String, ServiceProvider<InstanceDetails>> providers, String command) throws Exception {
if (args.length != 1) {
System.err.println("syntax error (expected random <name>): " + command);
return;
}
String serviceName = args[0];
ServiceProvider<InstanceDetails> provider = providers.get(serviceName);
if (provider == null) {
provider = serviceDiscovery.serviceProviderBuilder().serviceName(serviceName)
.providerStrategy(new RandomStrategy<InstanceDetails>()).build();
providers.put(serviceName, provider);
provider.start();
Thread.sleep(2500); // give the provider time to warm up - in a real application you wouldn't need
// to do this
}
ServiceInstance<InstanceDetails> instance = provider.getInstance();
if (instance == null) {
System.err.println("No instances named: " + serviceName);
} else {
outputInstance(instance);
}
}
private static void outputInstance(ServiceInstance<InstanceDetails> instance) {
System.out.println("\t" + instance.getPayload().getServiceDescription() + ": " + instance.buildUriSpec());
}
private static void listInstances(ServiceDiscovery<InstanceDetails> serviceDiscovery) throws Exception {
try {
Collection<String> serviceNames = serviceDiscovery.queryForNames();
System.out.println(serviceNames.size() + " type(s)");
for (String serviceName : serviceNames) {
Collection<ServiceInstance<InstanceDetails>> instances = serviceDiscovery
.queryForInstances(serviceName);
System.out.println(serviceName);
for (ServiceInstance<InstanceDetails> instance : instances) {
outputInstance(instance);
}
}
} catch (KeeperException.NoNodeException e) {
System.err.println("There are no registered instances.");
} finally {
CloseableUtils.closeQuietly(serviceDiscovery);
}
}
private static void printHelp() {
System.out.println(
"An example of using the ServiceDiscovery APIs. This example is driven by entering commands at the prompt:\n");
System.out.println("add <name> <description>: Adds a mock service with the given name and description");
System.out.println("delete <name>: Deletes one of the mock services with the given name");
System.out.println("list: Lists all the currently registered services");
System.out.println("random <name>: Lists a random instance of the service with the given name");
System.out.println("quit: Quit the example");
System.out.println();
}
private static void addInstance(String[] args, CuratorFramework client, String command, List<ExampleServer> servers)
throws Exception {
// simulate a new instance coming up
// in a real application, this would be a separate process
if (args.length < 2) {
System.err.println("syntax error (expected add <name> <description>): " + command);
return;
}
StringBuilder description = new StringBuilder();
for (int i = 1; i < args.length; ++i) {
if (i > 1) {
description.append(' ');
}
description.append(args[i]);
}
String serviceName = args[0];
ExampleServer server = new ExampleServer(client, PATH, serviceName, description.toString());
servers.add(server);
server.start();
System.out.println(serviceName + " added");
}
}
运行该类，出现如下界面
An example of using the ServiceDiscovery APIs. This example is driven by entering commands at the prompt:
add <name> <description>: Adds a mock service with the given name and description
delete <name>: Deletes one of the mock services with the given name
list: Lists all the currently registered services
random <name>: Lists a random instance of the service with the given name
quit: Quit the example
> list
There are no registered instances.
> add reg testing
reg added
> list
1 type(s)
reg
testing: http://foo.com:35438
> delete reg
Removed a random instance of: reg
> list
There are no registered instances.
> random reg2
No instances named: reg2
> list
1 type(s)
reg2
注意，delete的时候，可能需要等到时间轮询到才会删除，执行命令可能不会理解被删除。
三、示例2
通过模拟真实使用方式示例，即，定义一个serviceInstance、定义不同的服务提供方并注册至zookeeper、供消费方进行消费。模式是生产者-消费者模式。
本示例以来示例1的pom.xml和部分的文件，此处不再赘述。
1、InstanceDetails
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import lombok.Data;
/**
* @author alanchan
*
*/
@Data
public class InstanceDetails {
public static final String ROOT_PATH = "/service";
//该服务拥有哪些方法
public Map<String, Service> services = new HashMap<>();
//服务描述
private String serviceDescription;
public InstanceDetails() {
this.serviceDescription = "";
}
public InstanceDetails(String serviceDescription) {
this.serviceDescription = serviceDescription;
}
@Data
public static class Service {
//方法名称
private String methodName;
//方法描述
private String description;
//方法所需要的参数列表
private List<String> params;
}
}
2、ProviderService
可以注册很多的服务。
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.x.discovery.ServiceDiscovery;
import org.apache.curator.x.discovery.ServiceDiscoveryBuilder;
import org.apache.curator.x.discovery.ServiceInstance;
import org.apache.curator.x.discovery.ServiceInstanceBuilder;
import org.apache.curator.x.discovery.UriSpec;
import org.apache.curator.x.discovery.details.JsonInstanceSerializer;
import org.zookeeper_curator.App;
import org.zookeeper_curator.Constant;
public class ProviderService {
public static void main(String[] args) throws Exception {
CuratorFramework client = App.createWithOptions(Constant.zkServerAddress, Constant.retryPolicy,
Constant.CONNECTION_TIMEOUT, Constant.SESSION_TIMEOUT);
client.start();
client.blockUntilConnected();
// 该服务中所有的接口
Map<String, InstanceDetails.Service> services = new HashMap<>();
// 添加订单服务接口
InstanceDetails.Service addOrderService = new InstanceDetails.Service();
addOrderService.setDescription("添加订单");
addOrderService.setMethodName("addOrder");
ArrayList<String> addOrderParams = new ArrayList<>();
addOrderParams.add("createTime");
addOrderParams.add("state");
addOrderService.setParams(addOrderParams);
services.put("addOrder", addOrderService);
// 添加删除订单服务接口
InstanceDetails.Service delOrderService = new InstanceDetails.Service();
delOrderService.setDescription("删除订单");
delOrderService.setMethodName("delOrder");
ArrayList<String> delOrderParams = new ArrayList<>();
delOrderParams.add("orderId");
delOrderService.setParams(delOrderParams);
services.put("delOrder", delOrderService);
// 服务的其他信息
InstanceDetails payload = new InstanceDetails();
payload.setServiceDescription("订单服务");
payload.setServices(services);
// 服务构造器
ServiceInstanceBuilder<InstanceDetails> serviceInstanceBuilder = ServiceInstance.builder();
// 将订单服务添加到 ServiceInstance
ServiceInstance<InstanceDetails> orderService = serviceInstanceBuilder
.address("127.0.0.1")
.port(8082)
.name("OrderService")
.payload(payload)
.uriSpec(new UriSpec("{scheme}://{address}:{port}"))
.build();
// 构建 ServiceDiscovery 用来注册服务
ServiceDiscovery<InstanceDetails> serviceDiscovery = ServiceDiscoveryBuilder
.builder(InstanceDetails.class)
.client(client)
.serializer(new JsonInstanceSerializer<InstanceDetails>(InstanceDetails.class))
.basePath(InstanceDetails.ROOT_PATH)
.build();
// 服务注册
serviceDiscovery.registerService(orderService);
serviceDiscovery.start();
System.out.println("第一台服务注册成功......");
TimeUnit.SECONDS.sleep(Integer.MAX_VALUE);
serviceDiscovery.close();
client.close();
}
}
3、ConsumerService
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.x.discovery.ServiceDiscovery;
import org.apache.curator.x.discovery.ServiceDiscoveryBuilder;
import org.apache.curator.x.discovery.ServiceInstance;
import org.apache.curator.x.discovery.details.JsonInstanceSerializer;
import org.zookeeper_curator.App;
import org.zookeeper_curator.Constant;
/**
* @author alanchan
*
*/
public class ConsumerService {
public static void main(String[] args) throws Exception {
CuratorFramework client = App.createWithOptions(Constant.zkServerAddress, Constant.retryPolicy,
Constant.CONNECTION_TIMEOUT, Constant.SESSION_TIMEOUT);
client.start();
client.blockUntilConnected();
ServiceDiscovery<InstanceDetails> serviceDiscovery = ServiceDiscoveryBuilder
.builder(InstanceDetails.class)
.client(client)
.basePath(InstanceDetails.ROOT_PATH)
.serializer(new JsonInstanceSerializer<>(InstanceDetails.class))
.build();
serviceDiscovery.start();
// 根据名称获取服务
Collection<ServiceInstance<InstanceDetails>> services = serviceDiscovery.queryForInstances("OrderService");
System.out.println(services.toString());
for (ServiceInstance<InstanceDetails> service : services) {
// 获取请求的scheme 例如：http://127.0.0.1:8080
String uriSpec = service.buildUriSpec();
// 获取服务的其他信息
InstanceDetails payload = service.getPayload();
// 服务描述
String serviceDesc = payload.getServiceDescription();
// 获取该服务下的所有接口
Map<String, InstanceDetails.Service> allService = payload.getServices();
Set<Map.Entry<String, InstanceDetails.Service>> entries = allService.entrySet();
for (Map.Entry<String, InstanceDetails.Service> entry : entries) {
System.out.println(serviceDesc + uriSpec + "/" + service.getName() + "/" + entry.getKey()
+ " 该方法需要的参数为：" + entry.getValue().getParams().toString());
}
}
System.out.println("---------------------");
Thread.sleep(3 * 1000);
}
}
4、验证
该示例验证需要先启动ProviderService，再启动ConsumerService服务。
启动ProviderService后，控制台简单输出：
第一台服务注册成功…
启动ConsumerService服务后，控制台简单输出：
[ServiceInstance{name='OrderService', id='b6014a82-b924-4004-8790-27211457a23f', address='127.0.0.1', port=8082, sslPort=null, payload=InstanceDetails(services={delOrder=InstanceDetails.Service(methodName=delOrder, description=删除订单, params=[orderId]), addOrder=InstanceDetails.Service(methodName=addOrder, description=添加订单, params=[createTime, state])}, serviceDescription=订单服务), registrationTimeUTC=1659926704836, serviceType=DYNAMIC, uriSpec=org.apache.curator.x.discovery.UriSpec@6c2ac0dc, enabled=true}]
订单服务http://127.0.0.1:8082/OrderService/delOrder 该方法需要的参数为：[orderId]
订单服务http://127.0.0.1:8082/OrderService/addOrder 该方法需要的参数为：[createTime, state]
---------------------
如果启动多个ProviderService后（本例启动2个），每个控制台简单输出：
第一台服务注册成功…
启动ConsumerService服务后，控制台简单输出：
[ServiceInstance{name='OrderService', id='f79b7fb0-4979-4b32-a330-da028583fbf8', address='127.0.0.1', port=8082, sslPort=null, payload=InstanceDetails(services={delOrder=InstanceDetails.Service(methodName=delOrder, description=删除订单, params=[orderId]), addOrder=InstanceDetails.Service(methodName=addOrder, description=添加订单, params=[createTime, state])}, serviceDescription=订单服务), registrationTimeUTC=1682233116512, serviceType=DYNAMIC, uriSpec=org.apache.curator.x.discovery.UriSpec@6c2ac0dc, enabled=true}, ServiceInstance{name='OrderService', id='89e1f334-eae0-4116-8e83-dec65cfca8ea', address='127.0.0.1', port=8082, sslPort=null, payload=InstanceDetails(services={delOrder=InstanceDetails.Service(methodName=delOrder, description=删除订单, params=[orderId]), addOrder=InstanceDetails.Service(methodName=addOrder, description=添加订单, params=[createTime, state])}, serviceDescription=订单服务), registrationTimeUTC=1682232987649, serviceType=DYNAMIC, uriSpec=org.apache.curator.x.discovery.UriSpec@6c2ac0dc, enabled=true}]
订单服务http://127.0.0.1:8082/OrderService/delOrder 该方法需要的参数为：[orderId]
订单服务http://127.0.0.1:8082/OrderService/addOrder 该方法需要的参数为：[createTime, state]
订单服务http://127.0.0.1:8082/OrderService/delOrder 该方法需要的参数为：[orderId]
订单服务http://127.0.0.1:8082/OrderService/addOrder 该方法需要的参数为：[createTime, state]
本文来自博客园，作者：一瓢一瓢的饮，转载请注明原文链接：https://www.cnblogs.com/alanchan2win/p/17403668.html
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