Spring Boot custom starter pom instance

A simple example of custom starter pom
is implemented by itself. When a class exists, the bean is automatically configured, and this property can be configured in application.properties.

Create a new maven project (need to introduce spring-boot-autoconfigure )

Pom. xml

<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">  
  <modelVersion>4.0.0</modelVersion>  
  
  <groupId>com.ibigsea</groupId>  
  <artifactId>spring-boot-starter-hello</artifactId>  
  <version>0.0.1-SNAPSHOT</version>  
  <packaging>jar</packaging>  
  
  <name>spring-boot-starter-hello</name>  
  <url>http://maven.apache.org</url>  
  
  <properties>  
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
  </properties>  
  
  <dependencies>  
    <dependency>  
      <groupId>org.springframework.boot</groupId>  
      <artifactId>spring-boot-autoconfigure</artifactId>  
      <version>1.3.3.RELEASE</version>  
    </dependency>  
  </dependencies>  
</project>  

package com.ibigsea.spring_boot_starter_hello;  
  
/**
 * Configured by hello.msg of application.properties, the default is world
 * @author bigsea
 *
 */  
public class Hello {  
      
    private String msg;  
  
    public String sayHello() {  
        return "hello " + msg;  
    }  
      
    public String getMsg() {  
        return msg;  
    }  
  
    public void setMsg(String msg) {  
        this.msg = msg;  
    }  
      
}  

HelloProperties.java

package com.ibigsea.spring_boot_starter_hello;  
  
import org.springframework.boot.context.properties.ConfigurationProperties;  
  
/**
 * Property configuration, Spring boot's own automatic configuration
 * @author bigsea
 *
 */  
@ConfigurationProperties(prefix="hello")  
public class HelloProperties {  
      
    private static final String MSG = "world";  
      
    private String msg = MSG ;  
  
    public String getMsg() {  
        return msg;  
    }  
  
    public void setMsg(String msg) {  
        this.msg = msg;  
    }  
      
      
}  

HelloAutoConfiguration.java

package com.ibigsea.spring_boot_starter_hello;  
  
import org.springframework.beans.factory.annotation.Autowired;  
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;  
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;  
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;  
import org.springframework.boot.context.properties.EnableConfigurationProperties;  
import org.springframework.context.annotation.Bean;  
import org.springframework.context.annotation.Configuration;  
  
@Configuration  
@EnableConfigurationProperties(HelloProperties.class)//Enable property injection, injected through @autowired  
@ConditionalOnClass(Hello.class)//This class will only instantiate an object if it exists in the classpath
//When hello=enabled is set, if it is not set, the default is true, that is, the condition is met  
@ConditionalOnProperty(prefix="hello", value="enabled", matchIfMissing = true)  
public class HelloAutoConfiguration {  
      
    @Autowired  
    private HelloProperties helloProperties;  
      
    @Bean//Configure this class using java configuration  
    @ConditionalOnMissingBean(Hello.class)//If there is no Hello class instance in the container, then this Hello is automatically configured  
    public Hello hello() {  
        Hello hello = new Hello();  
        hello.setMsg(helloProperties.getMsg());  
        return hello;  
    }  
      
}  

and to add spring.factories

# Auto Configure  
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\  
com.ibigsea.spring_boot_starter_hello.HelloAutoConfiguration  

The entire project structure



Well , here we have completed a starter project, let's test

Pom.xml by ourselves

<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">  
  <modelVersion>4.0.0</modelVersion>  
  
  <groupId>com.ibigsea</groupId>  
  <artifactId>test-starter</artifactId>  
  <version>0.0.1-SNAPSHOT</version>  
  <packaging>jar</packaging>  
  
  <name>test-starter</name>  
  <url>http://maven.apache.org</url>  
  
    <properties>  
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
        <boot.version>1.3.3.RELEASE</boot.version>  
    </properties>  
  
    <dependencies>  
        <dependency>  
            <groupId>com.ibigsea</groupId>  
            <artifactId>spring-boot-starter-hello</artifactId>  
            <version>0.0.1-SNAPSHOT</version>  
        </dependency>  
        <dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-starter-web</artifactId>  
            <version>${boot.version}</version>  
        </dependency>  
        <dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-starter-test</artifactId>  
            <version>${boot.version}</version>  
            <scope>test</scope>  
        </dependency>  
    </dependencies>  
</project>  

App.java

package com.ibigsea.test_starter;  
  
import org.springframework.beans.factory.annotation.Autowired;  
import org.springframework.boot.SpringApplication;  
import org.springframework.boot.autoconfigure.SpringBootApplication;  
import org.springframework.web.bind.annotation.RequestMapping;  
import org.springframework.web.bind.annotation.RestController;  
  
import com.ibigsea.spring_boot_starter_hello.Hello;  
  
  
@SpringBootApplication   
@RestController  
public class App {  
      
    @Autowired  
    private Hello hello;  
      
    @RequestMapping("/")  
    public String index() {  
        return hello.sayHello();  
    }  
      
    public static void main(String[] args) {  
        SpringApplication.run(App.class, args);  
    }  
}  

Reprinted from: https://blog.csdn.net/a67474506/article/details/52013634