SpringBoot+Dubbo+Zookeeper build distributed project practice

1, Explanation of terms (from Baidu Encyclopedia):

Spring Boot is a new framework provided by pivot team. It is designed to simplify the initial construction and development process of new spring applications. The framework uses a specific way to configure, so that developers no longer need to define templated configurations.

Dubbo is a high-performance and excellent open source service framework of Alibaba company, which enables applications to realize service output and input functions through high-performance RPC, and can be seamlessly integrated with Spring framework.

ZooKeeper is a distributed, open-source distributed application coordination service. It is an open-source implementation of Chubby of Google and an important component of Hadoop and Hbase. It is a software that provides consistency services for distributed applications. Its functions include configuration maintenance, domain name service, distributed synchronization, group service, etc.

2, Project construction steps:

1. Install the local Zookeeper registry at: Apache Downloads

After downloading, unzip it, and then open the configuration and copy a zoo_sample.cfg, change the name to zoo.cfg, and open zoo_ CFG, modify the data saving path, as shown in the figure below, to a locally available path, and create the corresponding folder directory without:

Start zookeeper service, as shown in the following figure:

So far, Zookeeper has been started successfully.

2. Open the IDEA development tool, create a parent project based on maven SpringBoot, and then create three sub module modules based on the parent project. The final project structure is as follows:

1. Open the parent project pom.xml file and add the three sub modules just created, as shown in the following figure:

Note: < packaging > POM < / packaging > needs to be added manually.

 <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.0.RELEASE</version>
        <relativePath/>
    </parent>

    <groupId>org.example</groupId>
    <artifactId>springboot-dubbo-demo</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>

    <modules>
        <module>dubbo-api</module>
        <module>dubbo-provider</module>
        <module>dubbo-customer</module>
    </modules>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
    </dependencies>

2. Dubbo API module

Add a new service interface class HelloService with the following code:

public interface HelloService {
 
    String sayHello(String name);
}

The pom.xml code in Dubbo API is as follows:

     <parent>
        <artifactId>springboot-dubbo-demo</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <modelVersion>4.0.0</modelVersion>
    <artifactId>dubbo-api</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

3. Dubbo provider module

Add the implementation interface class HelloServiceImpl. The code is as follows:

import com.alibaba.dubbo.config.annotation.Service;
import com.api.service.HelloService;

@Service //Publishing services
public class HelloServiceImpl implements HelloService {
 
    @Override
    public String sayHello(String name) {
        return "Hello, " + name;
    }
}

Add dubbo annotation to the DubboProviderApplication startup class in dubbo provider. The code is as follows:

@EnableDubbo
@SpringBootApplication
public class DubboProviderApplication {
 
    public static void main(String[] args) {
        SpringApplication.run(DubboProviderApplication.class, args);
    }
 
}

pom.xml code in Dubbo provider is as follows:

   <parent>
        <artifactId>springboot-dubbo-demo</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <modelVersion>4.0.0</modelVersion>
    <artifactId>dubbo-provider</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <java.version>1.8</java.version>
        <zookeeper.version>3.4.13</zookeeper.version>
        <dubbo.version>0.2.0</dubbo.version>
    </properties>

    <dependencies>
        <dependency>
            <artifactId>dubbo-api</artifactId>
            <groupId>org.example</groupId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba.boot</groupId>
            <artifactId>dubbo-spring-boot-starter</artifactId>
            <version>${dubbo.version}</version>
        </dependency>

        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>${zookeeper.version}</version>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>log4j</groupId>
                    <artifactId>log4j</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

    </dependencies>

The configuration of application.yml in Dubbo provider is as follows:

server:
  port: 8000
 
dubbo:
  application:
    name: dubbo-provider
  protocol:
    name: dubbo
    port: 20880
  registry:
    address: zookeeper://127.0.0.1:2181

be careful:

@Service is the annotation of dubbo publishing service;
@EnableDubbo is the annotation to start the dubbo service;
Log4j and slf4j-log4j12 need to be excluded, otherwise they will conflict with zookeeper;

4. Dubbo customer module

A new control class HelloController is added to facilitate testing. The code is as follows:

@RestController
public class HelloController {
 
    @Reference //Reference service
    private HelloService helloService;
 
    @GetMapping("/sayHello")
    private String sayHello(@RequestParam String name){
 
        System.out.println("call sayHello succeed..." + " name:" + name);
 
        return helloService.sayHello(name);
    }
 
}

The pom.xml code in Dubbo customer is as follows:

 <parent>
        <artifactId>springboot-dubbo-demo</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>dubbo-customer</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <java.version>1.8</java.version>
        <zookeeper.version>3.4.13</zookeeper.version>
        <dubbo.version>0.2.0</dubbo.version>
    </properties>

    <dependencies>
        <dependency>
            <artifactId>dubbo-api</artifactId>
            <groupId>org.example</groupId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.alibaba.boot</groupId>
            <artifactId>dubbo-spring-boot-starter</artifactId>
            <version>${dubbo.version}</version>
        </dependency>

        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>${zookeeper.version}</version>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>log4j</groupId>
                    <artifactId>log4j</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

The configuration of application.yml in Dubbo customer is as follows:

server:
  port: 9000
 
dubbo:
  application:
    name: dubbo-customer
  registry:
    address: zookeeper://127.0.0.1:2181

Note: @ Reference is the annotation of dubbo Reference service;

So far, the distributed project framework based on dubbo has been built

3, Project consumption service function test:

1) First run the startup service provider Dubbo provider module

2) Then start the service consumer Dubbo customer module

3) The test results are as follows:

Tags: Java Spring Boot Distribution

Posted on Sat, 23 Oct 2021 08:42:09 -0400 by wih

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