1.Hazelcast介绍
Hazelcast是Hazelcast公司开源的一款分布式内存数据库产品，提供弹性可扩展、高性能的分布式内存计算。并通过提供诸如Map，Queue，ExecutorService，Lock和JCache等Java的许多开发人员友好的分布式实现。
Hazelcast优势
Hazelcast提供开源版本。
Hazelcast无需安装，只是个极小jar包。
Hazelcast提供开箱即用的分布式数据结构，如Map，Queue，MultiMap，Topic，Lock和Executor。
Hazelcast集群非传统主从关系，避免了单点故障；集群中所有成员共同分担集群功能。
Hazelcast集群提供弹性扩展，新成员在内存不足或负载过高时能动态加入集群。
Hazelcast集群中成员分担数据缓存的同时互相冗余备份其他成员数据，防止某成员离线后数据丢失。
Hazelcast提供SPI接口支持用户自定义分布式数据结构。
Hazelcast适用场景
频繁读写数据
需要高可用分布式缓存
内存行NoSql存储
分布式环境中弹性扩展
2.代码工程
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>springboot-demo</artifactId><groupId>com.et</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>hazelcast</artifactId><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-autoconfigure</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-cache</artifactId></dependency><dependency><groupId>com.hazelcast</groupId><artifactId>hazelcast-all</artifactId><version>4.0.2</version></dependency></dependencies></project>hazelcast.xml
<hazelcastxsi:schemaLocation="http://www.hazelcast.com/schema/confighttp://www.hazelcast.com/schema/config/hazelcast-config-3.12.12.xsd"xmlns="http://www.hazelcast.com/schema/config"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><instance-name>XML_Hazelcast_Instance</instance-name><network><join><multicast enabled="false"></multicast><tcp-ip enabled="true"><member>10.11.68.77</member></tcp-ip></join></network>
</hazelcast>application.yaml
server:port: 8090entity
package com.et.hazelcast.entity;
import java.io.Serializable;
public class Employee implements Serializable{private static final long serialVersionUID = 1L;private int empId;private String name;private String department;public Employee(Integer id, String name, String department) {super();this.empId = id;this.name = name;this.department = department;}public int getEmpId() {return empId;}public void setEmpId(int empId) {this.empId = empId;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getDepartment() {return department;}public void setDepartment(String department) {this.department = department;}@Overridepublic String toString() {return "Employee [empId=" + empId + ", name=" + name + ", department=" + department + "]";}
}controller
package com.et.hazelcast.controller;import com.et.hazelcast.entity.Employee;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;import java.util.HashMap;
import java.util.Map;@Controller
public class HelloWorldController {@RequestMapping("/hello")@ResponseBodypublic Map<String, Object> showHelloWorld(){Map<String, Object> map = new HashMap<>();map.put("msg", "HelloWorld");return map;}@Cacheable(value = "employee")@GetMapping("employee/{id}")@ResponseBodypublic Employee getSubscriber(@PathVariable("id") int id) throwsInterruptedException {System.out.println("Finding employee information with id " + id + " ...");return new Employee(id, "John Smith", "CS");}
}准备三个启动类
package com.et.hazelcast;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;@EnableCaching
@SpringBootApplication
public class HazelcastNode1Starter {public static void main(String[] args) {SpringApplication.run(HazelcastNode1Starter.class, args);}}package com.et.hazelcast;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
@EnableCaching
@SpringBootApplication
public class HazelcastNode2Starter {public static void main(String[] args) {SpringApplication.run(HazelcastNode2Starter.class, args);}
}package com.et.hazelcast;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
@EnableCaching
@SpringBootApplication
public class HazelcastNode3Starter {public static void main(String[] args) {SpringApplication.run(HazelcastNode3Starter.class, args);}
}java代码客户端
这个代码中最关键的参数是需要设置之前定义的cluster-name “hazelcast-cluster”。 这样就实现了对hazelcast集群中map的调用。上述过程中，如果关闭任意一个hazelcast节点，上述缓存中的数据都可用。很好的实现了分布式。
package com.et.hazelcast;import com.hazelcast.client.HazelcastClient;
import com.hazelcast.client.config.ClientConfig;
import com.hazelcast.core.HazelcastInstance;
import lombok.extern.slf4j.Slf4j;import java.util.Map;@Slf4j
public class HazelcastGetStartClient {public static void main(String[] args) {ClientConfig clientConfig = new ClientConfig();clientConfig.setClusterName("hazelcast-cluster");HazelcastInstance instance = HazelcastClient.newHazelcastClient(clientConfig);Map<Integer, String> clusterMap = instance.getMap("map");}}代码仓库
https://github.com/Harries/springboot-demo
3.测试
端口修改8088，启动HazelcastNode1Starter
端口修改8089，启动HazelcastNode2Starter
端口修改8090，启动HazelcastNode3Starter
Members {size:3, ver:5} [Member [10.11.68.77]:5701 - 2faf3b2d-76f3-493c-be48-d19d25aeb581 thisMember [10.11.68.77]:5702 - 63caca7f-f8ba-4b0a-989a-6e86a199fb72Member [10.11.68.77]:5703 - 3e9fa03c-72f4-4866-8904-73b908c4005d
]浏览器输入http://localhost:8088/employee/6，存入数据到hazelcast里面，控制台输出
Finding employee information with id 6 ...浏览器输入http://localhost:8089/employee/6，可以直接获取缓存数据，控制台不会打印日志出来
浏览器输入http://localhost:8090/employee/6，可以直接获取缓存数据，控制台不会打印日志出来
4.引用
http://element-ui.cn/news/show-552564.html
http://www.liuhaihua.cn/archives/710310.html
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