Spring Boot自定义starter pom实例（/META-INFO/spring.factory文件）

自定义starter pom
自己实现一个简单的例子,当某个类存在的时候,自动配置这个Bean,并且可以讲这个属性在application.properties中配置

新建一个maven项目（需要引入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;  
  
/** 
 * 通过application.properties的hello.msg来配置,默认为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;  
  
/** 
 * 属性配置,Spring boot 自身的自动配置 
 * @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)//开启属性注入,通过@autowired注入  
@ConditionalOnClass(Hello.class)//这个类在classpath中存在 才会实例化一个对象 
//当设置hello=enabled的情况下,如果没有设置则默认为true,即条件符合  
@ConditionalOnProperty(prefix="hello", value="enabled", matchIfMissing = true)  
public class HelloAutoConfiguration {  
      
    @Autowired  
    private HelloProperties helloProperties;  
      
    @Bean//使用java配置方式配置这个类  
    @ConditionalOnMissingBean(Hello.class)//容器中如果没有Hello这个类实例,那么自动配置这个Hello  
    public Hello hello() {  
        Hello hello = new Hello();  
        hello.setMsg(helloProperties.getMsg());  
        return hello;  
    }  
      
}  

并且要添加spring.factories

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

整个项目结构



好了,到这里我们就完成了一个starter项目了,下面自己测试下

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>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);  
    }  
}  

转自：https://blog.csdn.net/a67474506/article/details/52013634