SpringBoot自动配置实现

创建SpringBoot自动配置

新建一个Maven工程

创建安全配置类

package com.cvsea.test.spring_boot_starter_hello;

import org.springframework.boot.context.properties.ConfigurationProperties;

@ConfigurationProperties(prefix="hello")//引用application.properties中的配置
public class HelloServiceProperties {

private static final String MSG="world";

private String msg=MSG;

public String getMsg() {
return msg;
}

public void setMsg(String msg) {
this.msg = msg;
}

}

创建使用配置的Service

package com.cvsea.test.spring_boot_starter_hello;

public class HelloService {
private String msg;

public String getMsg() {
return msg;
}

public void setMsg(String msg) {
this.msg = msg;
}

public String sayHello()
{
return "Hello,"+msg;
}
}

创建自动配置类

package com.cvsea.test.spring_boot_starter_hello;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
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(HelloServiceProperties.class)
@ConditionalOnClass(HelloService.class)
@ConditionalOnProperty(prefix="hello",value="enabled",matchIfMissing=true)
public class HelloServiceAutoConfiguration {

@Autowired
private HelloServiceProperties helloServiceProperties;

@Bean
public HelloService helloService()
{
HelloService helloService=new HelloService();
helloService.setMsg(helloServiceProperties.getMsg());
return helloService;
}
}

使用spring.factories注册自动配置类

org.springframework.boot.autoconfiguration.EnableAutoConfig=com.cvsea.test.spring_boot_starter_hello.HelloServiceAutoConfiguration

测试

：使用starter创建一个SpringBoot项目，加入刚刚实现的自动配置的starter作为依赖

<dependency>
<groupId>com.cvsea</groupId>
<artifactId>spring-boot-starter-hello</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>

在application.properties添加配置内容

hello.msg=pxs

调用自动配置中的方法

package com.cvsea;

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.cvsea.test.spring_boot_starter_hello.HelloService;

@RestController
@SpringBootApplication
public class Learning1Application {

@Autowired
HelloService helloService;

@RequestMapping("/")
public String hello()
{
return helloService.sayHello();
}

public static void main(String[] args) {
SpringApplication.run(Learning1Application.class, args);
}
}