springboot自动配置demo

Posted on | Edited on

先创建需要自动配置的类

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package com.jianganwei.autoconfigdemo.demo;

import org.springframework.beans.factory.annotation.Value;

public class AutoconfigDemo {
    @Value("${init.message}")
    private String message;

    public void sout() {
        System.out.println("the message is: " + message);
    }
}

编写创建该类的条件

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import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class Demo {
    @Bean
    @ConditionalOnMissingBean(AutoconfigDemo.class)
    @ConfigurationProperties(prefix = "init")
    @ConditionalOnProperty(prefix = "init",value = "message")
   public AutoconfigDemo getDemo(){
        return new AutoconfigDemo();
    }
}

最后在resources 目录下创建 META-INF/spring.factories

在文件中配入需要自动创建的bean 条件类

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org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.jianganwei.autoconfigdemo.demo.Demo