Java-sdk的开发

java , 评论

前言

在公司的开发中, 我们经常会开发一些jar供其他业务小组使用, 在当前 spring 为主的开发环境下, 我们应该如何去包装一个jar让大家更加方便的使用呢？这里就涉及到sdk的开发, 比如kafka出品的 kafka-client 提供核心业务代码, 然后用 spring-kafka 包装 kafka-client 供 spring 更加方便的调用。这里我们模仿这种思路做一个简单的sdk开发流程介绍。

kafka-client的开发

我们通过构造方法简单的读取参数来模拟一个 kafka-client, 能够将读取的变量打印出来即可。

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/**
 * @author cc
 * @description 模拟一个客户端sdk
 * @date 2020-12-30
 */
public class KafkaClient {

    public KafkaClient(Properties properties) {
        this(propsToMap(properties));
    }

    KafkaClient(Map<String, Object> configs) {
        ClientConfig config = new ClientConfig(configs);
    }

    private static Map<String, Object> propsToMap(Properties properties) {
        Map<String, Object> map = new HashMap(properties.size());
        Iterator var2 = properties.entrySet().iterator();

        while(var2.hasNext()) {
            Map.Entry<Object, Object> entry = (Map.Entry)var2.next();
            if (!(entry.getKey() instanceof String)) {
                throw new RuntimeException(entry.getKey().toString() + entry.getValue() + "Key must be a string.");
            }

            String k = (String)entry.getKey();
            map.put(k, properties.get(k));
        }

        return map;
    }
}

配置文件对象

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public class ClientConfig extends AbstractConfig{

    public ClientConfig(Map<String, Object> props) {
        super(props, true);
    }

}
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public class AbstractConfig {

    Logger logger = Logger.getLogger("AbstractConfig");

    public AbstractConfig(Map<?, ?> originals, boolean doLog) {
        for (Map.Entry<?, ?> entry : originals.entrySet()) {
            if (doLog) {
                logger.info("读取到配置文件:[" + entry.getKey() + ":" + entry.getValue() + "]");
            }
        }
    }
}

然后我们测试下效果

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public class Test {

    /**
     * 1月 03, 2021 12:55:48 下午 cn.idea360.AbstractConfig <init>
     * 信息: 读取到配置文件:[name:admin]
     * 1月 03, 2021 12:55:48 下午 cn.idea360.AbstractConfig <init>
     * 信息: 读取到配置文件:[password:123456]
     * 
     * @param args
     */
    public static void main(String[] args) {
        Properties properties = new Properties();
        properties.setProperty("name", "admin");
        properties.setProperty("password", "123456");
        new KafkaClient(properties);
    }
}

由结果可见，我们的sdk已经可以正常使用, 将jar打包进我们的本地maven仓库, 接下来我们来包装spring-boot-adapter

kafka-spring-boot-starter开发

我们自定义的starter要遵守官方推荐的命名规范 xxx-spring-boot-starter。
在我们使用开源社区提供的jar包时发现，好多变量在配置的时候是有提示补全功能的，这个我们也来实现下。

  1. 首先引入pom.xml依赖
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<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
        <version>2.4.1</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-configuration-processor</artifactId>
        <version>2.4.1</version>
    </dependency>
    <dependency>
        <groupId>cn.idea360</groupId>
        <artifactId>idea360-kafka-client</artifactId>
        <version>1.0-SNAPSHOT</version>
    </dependency>
</dependencies>
  1. 创建配置类

@ConfigurationProperties 注解即是配置变量补全的关键

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@Configuration
@ConfigurationProperties(prefix = "idea360.kafka")
public class DemoProperties {

    private String name;
    private String password;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}
  1. 将配置信息注入sdk的bean对象 kafka-client 中
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@Configuration
@EnableConfigurationProperties(DemoProperties.class)
public class DemoConfig {

    @Bean
    public KafkaClient kafkaClient(DemoProperties demoProperties) {
        Properties properties = new Properties();
        properties.setProperty("name", demoProperties.getName());
        properties.setProperty("password", demoProperties.getPassword());
        return new KafkaClient(properties);
    }
}
  1. 按照spring的spi机制定义自启动类。 在 src/main/resources/META-INF/spring.factories 文件中定义
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org.springframework.boot.autoconfigure.EnableAutoConfiguration=cn.idea360.starter.DemoConfig
  1. 将我们包装好的starter打包进本地maven仓库

自定义starter测试

  1. 创建一个普通的spring-boot项目, pom.xml如下
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<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>cn.idea360</groupId>
    <artifactId>idea360-kafka-spring-boot-demo</artifactId>
    <version>0.0.1</version>
    <name>dea360-kafka-spring-boot-demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.3.7.RELEASE</spring-boot.version>
    </properties>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.example</groupId>
            <artifactId>idea360-kafka-spring-boot-starter</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.3.7.RELEASE</version>
                <configuration>
                    <mainClass>cn.idea360.springdemo.SpringDemoApplication</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>
  1. 配置application.properties
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# 应用名称
spring.application.name=idea360-kafka-spring-boot-demo
# 应用服务 WEB 访问端口
server.port=8080

idea360.kafka.name=admin
idea360.kafka.password=123456

这里我们看到已经可以自动提示补全参数了

  1. 启动springboot项目, 控制台我们看到上边我们配置的参数已经被正确注入到了 kafka-client 中。
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2021-01-03 13:10:53.402  INFO 13169 --- [           main] AbstractConfig                           : 读取到配置文件:[name:admin]
2021-01-03 13:10:53.402  INFO 13169 --- [           main] AbstractConfig                           : 读取到配置文件:[password:123456]

最后

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