SpringBoot-annotation

/Enable the ConfigurationProperties annotated beans

@SpringBootApplication
@EnableConfigurationProperties({ConfigBean.class,TestConfigBean.class})
@ImportResource({"classpath:some-application.xml"})

@Value("${mrbird.blog.name}")
private String name;

@ConfigurationProperties(prefix="mrbird.blog")

//Specify the property source and its prefix
@Configuration
@ConfigurationProperties(prefix="test")
@PropertySource("classpath:test.properties")
@Component

Disabling Specific Auto-configuration Classes

@Configuration
@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})
public class MyConfiguration {
}

 Specify the packaged scaned by spring same as <context:component-scan>

You can add @ComponentScan without any arguments. All of your application components (@Component, @Service, @Repository, @Controller etc.) are automatically registered as Spring Beans.

@ComponentScan

@SpringBootApplication // same as @Configuration @EnableAutoConfiguration @ComponentScan

• @EnableAutoConfiguration: enable Spring Boot’s auto-configuration mechanism
• @ComponentScan: enable @Component scan on the package where the application is located (see the best practices)
• @Configuration: allow to register extra beans in the context or import additional configuration classes

The user-defined beans are imported explicitly, these beans are not in package defined in

@ComponentScan with arguments or even no annotation @ComponentScan 

@Import({ MyConfig.class, MyAnotherConfig.class })

<build>
    <resources>
       <resource>
           <directory>src/main/resources</directory>
        </resource>
     </resources>
   <plugins>
       <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <configuration>
               <encoding>UTF-8</encoding>
               <mainClass>com.iot.gateway.admin.Application</mainClass>
            </configuration>
       </plugin>
    </plugins>
</build>

    <repositories>
        <repository>
            <id>nexus-aliyun</id>
            <name>Nexus aliyun</name>
            <url>http://maven.aliyun.com/nexus/content/groups/public</url>
        </repository>
    </repositories>

<dependencyManagement>
    <dependencies>
        <!-- Override Spring Data release train provided by Spring Boot -->
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-releasetrain</artifactId>
            <version>Fowler-SR2</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-dependencies</artifactId>
            <version>2.1.0.BUILD-SNAPSHOT</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

SpringApplication.setRegisterShutdownHook(false)

The spring-boot-devtools module can be included in any project to provide additional development-time features

<dependencies>
	<dependency>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-devtools</artifactId>
		<optional>true</optional>
	</dependency>
</dependencies>

　　

System.setProperty("spring.devtools.restart.enabled", "false");

Output debug information

$ java -jar myproject-0.0.1-SNAPSHOT.jar --debug

Accessing Application Arguments

@Component
public class MyBean {

	@Autowired
	public MyBean(ApplicationArguments args) {
		boolean debug = args.containsOption("debug");
		List<String> files = args.getNonOptionArgs();
		// if run with "--debug logfile.txt" debug=true, files=["logfile.txt"]
	}

}

Spring Boot also registers a CommandLinePropertySource with the Spring Environment. This lets you also inject single application arguments by using the @Value annotation.

Using the ApplicationRunner or CommandLineRunner

@Component
public class MyBean implements CommandLineRunner {

	public void run(String... args) {
		// Do something...
	}

}

Application Exit

Each SpringApplication registers a shutdown hook with the JVM to ensure that the ApplicationContext closes gracefully on exit.

All the standard Spring lifecycle callbacks (such as the DisposableBean interface or the @PreDestroy annotation) can be used.

Externalized Configuration/Application Property Files

1. file:./custom-config/
2. classpath:custom-config/
3. file:./config/
4. file:./
5. classpath:/config/
6. classpath:/

Profile-specific Properties

application-{profile}.properties

spring.profiles.active

Define the context path

server:
     context-path: /web

DruidDataSourceAutoConfigure

@Configuration
@ConditionalOnClass(com.alibaba.druid.pool.DruidDataSource.class)
@AutoConfigureBefore(DataSourceAutoConfiguration.class)
@EnableConfigurationProperties({DruidStatProperties.class, DataSourceProperties.class})
@Import({DruidSpringAopConfiguration.class,
        DruidStatViewServletConfiguration.class,
        DruidWebStatFilterConfiguration.class,
        DruidFilterConfiguration.class})

@ConditionalOnProperty("spring.datasource.druid.aop-patterns")

//
@Value("${spring.aop.proxy-target-class:false}")

//
@Bean
    @ConfigurationProperties(FILTER_STAT_PREFIX)
    @ConditionalOnProperty(prefix = FILTER_STAT_PREFIX, name = "enabled", matchIfMissing = true)
    @ConditionalOnMissingBean
    public StatFilter statFilter() {
        return new StatFilter();
    }

//
@ConditionalOnWebApplication
@ConditionalOnProperty(name = "spring.datasource.druid.stat-view-servlet.enabled", havingValue = "true", matchIfMissing = true)

//
@Configuration
@ConditionalOnClass(com.alibaba.druid.pool.DruidDataSource.class)
@AutoConfigureBefore(DataSourceAutoConfiguration.class)
@EnableConfigurationProperties({DruidStatProperties.class, DataSourceProperties.class})
@Import({DruidSpringAopConfiguration.class,
        DruidStatViewServletConfiguration.class,
        DruidWebStatFilterConfiguration.class,
        DruidFilterConfiguration.class})

@org.springframework.context.annotation.Configuration
@ConditionalOnClass({ SqlSessionFactory.class, SqlSessionFactoryBean.class })
@ConditionalOnBean(DataSource.class)
@EnableConfigurationProperties(MybatisProperties.class)
@AutoConfigureAfter(DataSourceAutoConfiguration.class)

　@NestedConfigurationProperty　

 Use SpringBean in Filter

@Override
public void init(FilterConfig filterConfig) throws ServletException {
	SpringBeanAutowiringSupport.processInjectionBasedOnServletContext(this, filterConfig.getServletContext());
}

ServletContext servletContext = filterConfig.getServletContext();
WebApplicationContext wac = WebApplicationContextUtils.getWebApplicationContext(servletContext);
tokenService = wac.getBean(TokenService.class);

Multi-Datasource and Multi-JdbcTemplate

@Configuration
public class DataSourceConfig {
	@Primary
	@Bean(name = "mysqldatasource")
	@ConfigurationProperties("spring.datasource.druid.mysql")
	public DataSource dataSourceOne(){
	    return DruidDataSourceBuilder.create().build();
	}	
	@Bean(name = "oracledatasource")
	@ConfigurationProperties("spring.datasource.druid.oracle")
	public DataSource dataSourceTwo(){
	    return DruidDataSourceBuilder.create().build();
	}
	@Bean(name = "mysqlJdbcTemplate")
	public JdbcTemplate primaryJdbcTemplate(@Qualifier("mysqldatasource") DataSource dataSource) {
	    return new JdbcTemplate(dataSource);
	}	
	@Bean(name = "oracleJdbcTemplate")
	public JdbcTemplate secondaryJdbcTemplate(@Qualifier("oracledatasource") DataSource dataSource) {
	    return new JdbcTemplate(dataSource);
	}
}

@Repository
public class MysqlStudentDaoImp implements MysqlStudentDao{	
	@Autowired
	@Qualifier("mysqlJdbcTemplate")
	private JdbcTemplate jdbcTemplate;

	@Override
	public List<Map<String, Object>> getAllStudents() {
		return this.jdbcTemplate.queryForList("select * from student");
	}
}

Spring Import Beans

//
@Import({User.class,Role.class})


//
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@PropertySource("classpath:/wx.properties")
@EnableConfigurationProperties(WxProperties.class)
@Import({WxInvokerConfiguration.class,
        WxAsyncMessageConfiguration.class,
        WxBuildinMvcConfiguration.class,
        WxTokenConfiguration.class,
        WxMediaConfiguration.class,
        WxWebConfiguration.class})
public @interface EnableWxMvc{
}

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@SpringBootApplication
@EnableWxMvc
public @interface WxApplication {
}

//
public class MyConfig { 	
  @Bean	
  public Runnable createRunnble1() {		
     return () -> {};		
  }	
}

@Import({MyConfig .class})

//

@Import({MyImportSelector.class,MyImportBeanDefinitionRegistrar })
public class MyImportSelector implements ImportSelector{ 	
@Override	
public String[] selectImports(AnnotationMetadata importingClassMetadata) {		
//可以获取到注解信息，然后根据注解信息动态的返回被spring容器托管的bean		System.out.println(importingClassMetadata.getAnnotationAttributes(EnableLog.class.getName()));		
return new String[] User.class.getName(),Role.class.getName(),MyConfig.class.getName()};	} }

public class MyImportBeanDefinitionRegistrar implements ImportBeanDefinitionRegistrar{
}

HttpMessageConverter