springBoot @EnableAutoConfiguration深入分析

package com.boot.config.core.domain;public class Order {}

package com.boot.config.core.domain;public class Product {}

package com.boot.config.core.config;import com.boot.config.core.domain.Order;import com.boot.config.core.domain.Product;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;@Configurationpublic class BeanConfiguration {    @Bean    public Order createOrder() {        return new Order();    }    @Bean    public Product createProduct() {        return new Product();    }}

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\com.boot.config.core.config.BeanConfiguration

package com.boot.config.core;/** * 数据源的属性类 */public class DatasourceProperties {    private String driverClassName;    private String url;    private String username;    private String password;    public String getDriverClassName() {        return driverClassName;    }    public void setDriverClassName(String driverClassName) {        this.driverClassName = driverClassName;    }    public String getUrl() {        return url;    }    public void setUrl(String url) {        this.url = url;    }    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    public String getPassword() {        return password;    }    public void setPassword(String password) {        this.password = password;    }}

package com.boot.config.core;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;@Configurationpublic class DataSourceConfig {    @Bean    @ConfigurationProperties(prefix = "jdbc")    public DatasourceProperties createDatasource() {        return new DatasourceProperties();    }}

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\com.boot.config.core.DataSourceConfig

<?xml version="1.0" encoding="UTF-8"?><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.boot.auto.config</groupId>    <artifactId>boot-auto</artifactId>    <version>0.0.1-SNAPSHOT</version>    <packaging>jar</packaging>    <name>boot-auto</name>    <description>Demo project for Spring Boot</description>    <parent>        <groupId>org.springframework.boot</groupId>        <artifactId>spring-boot-starter-parent</artifactId>        <version>2.0.6.RELEASE</version>        <relativePath/> <!-- lookup parent from repository -->    </parent>    <properties>        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>        <java.version>1.8</java.version>    </properties>    <dependencies>        <!--引入三方依赖-->        <dependency>            <groupId>com.boot.config.core</groupId>            <artifactId>bean-core</artifactId>            <version>1.0-SNAPSHOT</version>        </dependency>        <dependency>            <groupId>com.boot.demo</groupId>            <artifactId>config-demo</artifactId>            <version>0.0.1-SNAPSHOT</version>        </dependency>    <!--gson是springboot中装配的对象-->        <dependency>            <groupId>com.google.code.gson</groupId>            <artifactId>gson</artifactId>            <version>2.8.0</version>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-web</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-test</artifactId>            <scope>test</scope>        </dependency>    </dependencies>    <build>        <plugins>            <plugin>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-maven-plugin</artifactId>            </plugin>        </plugins>    </build></project>

jdbc.driverClassName = com.mysql.jdbc.Driver#spring.boot.enableautoconfiguration = false   关闭配置功能，默认为true

package com.boot.auto.config.bootauto;import com.boot.config.core.DatasourceProperties;import com.boot.config.core.domain.Order;import com.boot.config.core.domain.Product;import com.google.gson.Gson;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.context.ConfigurableApplicationContext;// 这种方式只能排除配置类// @EnableAutoConfiguration(exclude = {BeanConfiguration.class, DataSourceConfig.class})// @EnableAutoConfiguration(excludeName = "com.boot.config.core.config.BeanConfiguration")// @ComponentScan@SpringBootApplication// 注意点： exclude和excludeName 排除的类必须是配置类public class BootAutoApplication {    public static void main(String[] args) {        ConfigurableApplicationContext context =                SpringApplication.run(BootAutoApplication.class, args);        System.out.println(context.getBean(Order.class));        System.out.println(context.getBean(Product.class));        System.out.println(context.getBean(DatasourceProperties.class).getDriverClassName());        System.out.println(context.getBean("gson", Gson.class));        context.close();    }}

//// Source code recreated from a .class file by IntelliJ IDEA// (powered by Fernflower decompiler)//package org.springframework.boot.autoconfigure.gson;import com.google.gson.Gson;import com.google.gson.GsonBuilder;import java.util.List;import java.util.function.Consumer;import java.util.function.Supplier;import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;import org.springframework.boot.context.properties.EnableConfigurationProperties;import org.springframework.boot.context.properties.PropertyMapper;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.core.Ordered;@Configuration@ConditionalOnClass({Gson.class})@EnableConfigurationProperties({GsonProperties.class})public class GsonAutoConfiguration {    public GsonAutoConfiguration() {    }    @Bean    @ConditionalOnMissingBean    public GsonBuilder gsonBuilder(List<GsonBuilderCustomizer> customizers) {        GsonBuilder builder = new GsonBuilder();        customizers.forEach((c) -> {            c.customize(builder);        });        return builder;    }    @Bean    @ConditionalOnMissingBean    public Gson gson(GsonBuilder gsonBuilder) {        return gsonBuilder.create();    }    @Bean    public GsonAutoConfiguration.StandardGsonBuilderCustomizer standardGsonBuilderCustomizer(GsonProperties gsonProperties) {        return new GsonAutoConfiguration.StandardGsonBuilderCustomizer(gsonProperties);    }    private static final class StandardGsonBuilderCustomizer implements GsonBuilderCustomizer, Ordered {        private final GsonProperties properties;        StandardGsonBuilderCustomizer(GsonProperties properties) {            this.properties = properties;        }        public int getOrder() {            return 0;        }        public void customize(GsonBuilder builder) {            GsonProperties properties = this.properties;            PropertyMapper map = PropertyMapper.get().alwaysApplyingWhenNonNull();            properties.getClass();            map.from(properties::getGenerateNonExecutableJson).toCall(builder::generateNonExecutableJson);            properties.getClass();            map.from(properties::getExcludeFieldsWithoutExposeAnnotation).toCall(builder::excludeFieldsWithoutExposeAnnotation);            properties.getClass();            map.from(properties::getSerializeNulls).toCall(builder::serializeNulls);            properties.getClass();            map.from(properties::getEnableComplexMapKeySerialization).toCall(builder::enableComplexMapKeySerialization);            properties.getClass();            map.from(properties::getDisableInnerClassSerialization).toCall(builder::disableInnerClassSerialization);            properties.getClass();            map.from(properties::getLongSerializationPolicy).to(builder::setLongSerializationPolicy);            properties.getClass();            map.from(properties::getFieldNamingPolicy).to(builder::setFieldNamingPolicy);            properties.getClass();            map.from(properties::getPrettyPrinting).toCall(builder::setPrettyPrinting);            properties.getClass();            map.from(properties::getLenient).toCall(builder::setLenient);            properties.getClass();            map.from(properties::getDisableHtmlEscaping).toCall(builder::disableHtmlEscaping);            properties.getClass();            map.from(properties::getDateFormat).to(builder::setDateFormat);        }    }}