127.【SpringBoot 源码刨析D】（五）

package com.jsxs.bean;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.stereotype.Component;
/**
 * @Author Jsxs
 * @Date 2023/7/29 13:29
 * @PackageName:com.jsxs
 * @ClassName: HelloProperties
 * @Description: TODO
 * @Version 1.0
 */
@ConfigurationProperties("atguigu.hello")
public class HelloProperties {
    private String prefix;
    private String suffix;
    public String getPrefix() {
        return prefix;
    }
    public void setPrefix(String prefix) {
        this.prefix = prefix;
    }
    public String getSuffix() {
        return suffix;
    }
    public void setSuffix(String suffix) {
        this.suffix = suffix;
    }
}

package com.jsxs.service;
import com.jsxs.bean.HelloProperties;
import javax.annotation.Resource;
/**
 * @Author Jsxs
 * @Date 2023/7/29 13:27
 * @PackageName:com.jsxs.service
 * @ClassName: HelloService
 * @Description: TODO
 * @Version 1.0
 */
public class HelloService {
    @Resource
    HelloProperties helloProperties;
    public String sayHello(String username) {
        return helloProperties.getPrefix() + ": " + username + ">" + helloProperties.getSuffix();
    }
}

package com.jsxs.auto;
import com.jsxs.bean.HelloProperties;
import com.jsxs.service.HelloService;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingClass;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
/**
 * @Author Jsxs
 * @Date 2023/7/29 13:37
 * @PackageName:com.jsxs.auto
 * @ClassName: HelloServiceAutoConfig
 * @Description: TODO
 * @Version 1.0
 */
@Configuration
@ConditionalOnMissingBean(HelloService.class)  // 1.假如没存在这个组件，就自动引入
@EnableConfigurationProperties(HelloProperties.class)  // 1.将属性放入容器 2.且绑定属性
public class HelloServiceAutoConfig {
    @Bean
    public HelloService helloService(){
        return new HelloService();
    }
}

# Auto Configure
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
com.jsxs.auto.HelloServiceAutoConfig

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

package com.jsxs.Controller;
import com.jsxs.service.HelloService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
/**
 * @Author Jsxs
 * @Date 2023/7/29 14:15
 * @PackageName:com.jsxs.Controller
 * @ClassName: HelloController
 * @Description: TODO
 * @Version 1.0
 */
@RestController
public class HelloController {
    @Resource
    HelloService helloService;
    @GetMapping("/")
    public String sayHello(){
        return helloService.sayHello("李明");
    }
}

atguigu.hello.prefix:你好
atguigu.hello.suffix:!

public static ConfigurableApplicationContext run(Class<?>[] primarySources, String[] args) {
    return new SpringApplication(primarySources).run(args);
  }

/*
 * Copyright 2012-2020 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.springframework.boot;
/**
 * Callback interface that can be used to initialize a {@link BootstrapRegistry} before it
 * is used.
 *
 * @author Phillip Webb
 * @since 2.4.0
 * @see SpringApplication#addBootstrapper(Bootstrapper)
 * @see BootstrapRegistry
 */
public interface Bootstrapper {
  /**
   * Initialize the given {@link BootstrapRegistry} with any required registrations.
   * @param registry the registry to initialize
   */
  void intitialize(BootstrapRegistry registry);
}