spring-boot基础

什么是Spring Boot

Spring Boot是由Pivotal团队提供的全新框架，其设计目的是用来简化新Spring应用的初始搭建以及开发过程。使用Spring Boot框架可以做到专注于Spring应用的开发，无须过多关注样板化的配置。
在Spring Boot框架中，使用“约定优于配置（Convention Over Configuration，COC）”的理念。

优点

（1）使编码变得简单：推荐使用注解。
（2）使配置变得快捷：具有自动配置、快速构建项目、快速集成第三方技术的能力。
（3）使部署变得简便：内嵌Tomcat、Jetty等Web容器。
（4）使监控变得容易：自带项目监控。

@SpringBootApplication

@SpringBootApplication
@Slf4j
public class HelloApplication {
    public static void main(String[] args) {
        SpringApplication.run(HelloApplication.class, args);
    }
}


@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan(excludeFilters = { @Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class),
        @Filter(type = FilterType.CUSTOM, classes = AutoConfigurationExcludeFilter.class) })
public @interface SpringBootApplication {


@Configuration
public @interface SpringBootConfiguration {

@Configuration(Spring的注解，不是SpringBoot)

注解的作用：声明一个类为配置类，用于取代bean.xml配置文件注册bean对象

设置端口号

server.port=8888

@Value

    @Value("${spring.profiles.active}")
    private String activeProfile;

@ConfigurationProperties

@ConfigurationProperties(
        prefix = "jnt.id"
)
@Component
@Data
public class JntIDProperties {

    @NestedConfigurationProperty
    private JntIDProperties.CreateOrder createOrder;

    @NestedConfigurationProperty
    private JntIDProperties.Track tracking;

    @NestedConfigurationProperty
    private JntIDProperties.ConsignmentNote consignmentNote;

@PropertySource

//a.properties
a.msg=hello a
//b.properties
b.msg=hello b
@Controller
@PropertySource("a.properties","b.properties")
public class MyController{
    @Value("${a.msg}")
     public String aMsg;
    @Value("${b.msg}")
     public String bMsg;
}

Spring Boot的自动配置原理

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public final class SpringFactoriesLoader {

    /**
     * The location to look for factories.
     * <p>Can be present in multiple JAR files.
     */
    public static final String FACTORIES_RESOURCE_LOCATION = "META-INF/spring.factories";

@SpringBootApplication注解通过使用@EnableAutoConfiguration注解自动配置的原理是：从classpath中搜索所有META-INF/spring.factories配置文件，并将其中org.springframework.boot.autoconfigure.EnableAutoConfiguration对应的配置项通过Java反射机制进行实例化，然后汇总并加载到Spring的IoC容器。

条件注解(@ConditionalXXX)

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自定义条件

public class MyCondition implements Condition {
    @Override
    public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
        return false;
    }
}

mybatis-spring-boot-starter

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#spring.factories
# Auto Configure
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
org.mybatis.spring.boot.autoconfigure.MybatisLanguageDriverAutoConfiguration,\
org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration

@ConditionalOnClass({ SqlSessionFactory.class, SqlSessionFactoryBean.class })
@ConditionalOnSingleCandidate(DataSource.class)
@EnableConfigurationProperties(MybatisProperties.class)
//控制加载顺序
@AutoConfigureAfter({ DataSourceAutoConfiguration.class, MybatisLanguageDriverAutoConfiguration.class }) 
public class MybatisAutoConfiguration implements InitializingBean {

自定义starter

添加spring.factories

#spring.factories
org.springframework.boot.autoconfigure.EnableAutoConfiguration=shop.xxx.common.env.configuration.ApplicationReadyListener

实现 ApplicationReadyListener

@Configuration
public class ApplicationReadyListener implements ApplicationListener<ApplicationReadyEvent> {

spring-boot redis 集成

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-redis</artifactId>
        <version>2.0.4.RELEASE</version>
</dependency>

spring:
    redis:
        database: 0
        host: 127.0.0.1
        port: 6379
        jedis:
          pool:
            max-active: 100
            max-idle: 10
            max-wait: 100000
        timeout: 5000

可选

@Configuration
@ConditionalOnClass(RedisOperations.class)
@EnableConfigurationProperties(RedisProperties.class)
public class RedisConfig {


    @Bean
    @ConditionalOnMissingBean(name = "redisTemplate")
    public RedisTemplate<Object, Object> redisTemplate(
            RedisConnectionFactory redisConnectionFactory) {
        RedisTemplate<Object, Object> template = new RedisTemplate<>();
        //使用fastjson序列化
        FastJsonRedisSerializer fastJsonRedisSerializer = new FastJsonRedisSerializer(Object.class);
        // value值的序列化采用fastJsonRedisSerializer
        template.setValueSerializer(fastJsonRedisSerializer);
        template.setHashValueSerializer(fastJsonRedisSerializer);
        // key的序列化采用StringRedisSerializer
        template.setKeySerializer(new StringRedisSerializer());
        template.setHashKeySerializer(new StringRedisSerializer());
        template.setConnectionFactory(redisConnectionFactory);
        return template;
    }

    @Bean
    @ConditionalOnMissingBean(StringRedisTemplate.class)
    public StringRedisTemplate stringRedisTemplate(
            RedisConnectionFactory redisConnectionFactory) {
        StringRedisTemplate template = new StringRedisTemplate();
        template.setConnectionFactory(redisConnectionFactory);
        return template;
    }

}

spring aop

@Aspect
@Component
@Slf4j
public class OAuthAspect {

    @Pointcut(value = "@annotation(shop.melf.social.server.core.facebbook.FbOAuthAnnotation)")
    public void servicePointcut() {
    }


    @Around(value = "servicePointcut()")
    @SneakyThrows
    public Object bossAround(ProceedingJoinPoint joinPoint) {

@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface FbOAuthAnnotation {
    boolean pageAccessToken() default false;
    boolean refreshToken() default false;
}

    @SneakyThrows
    @FbOAuthAnnotation(pageAccessToken = true)
    public LiveVideoResp lives(FbEnv param, String status) {
        LiveVideoReq req = new LiveVideoReq();
        req.setStatus(status);
        req.setFbPageId(param.getFbPageId());
        LiveVideoResp result = client.execute(req, param.getPageAccessToken(redisService, param), true);
        OAuthAspect.autCheck2(param, result,req);
        return result;
    }

ApplicationEvent & ApplicationListener

public class DemoEvent extends ApplicationEvent {
 
 private static final long serialVersionUID = 1L;
 private String msg;
 
 public DemoEvnet(Object source, String msg) {
  super(source);
  this.msg = msg;
 }
 
 public String getMsg() {
  return msg;
 }
 
 public void setMsg(String msg) {
  this.msg = msg;
 }
}

@Component
public class DemoListener implements ApplicationListener<DemoEvent> {
 
 public void onApplicationEvent(DemoEvent event) {
  String msg = event.getMsg();
  System.out.println("接收到了消息：" + msg);
 }
}

@Component
public class DemoPublisher {
 @Autowired
 ApplicationContext applicationContext;
 
 public void publish(String msg) {
  applicaionContext.publishEvent(new DemoEvent(this, msg));
 }
}

@Configuration
@EnableAsync
public class AsyncTaskExecutorConfig {
    @Bean
    public Executor asyncTaskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(5);
        executor.setMaxPoolSize(5);
        executor.setQueueCapacity(200);
        executor.setThreadNamePrefix("async-erp-task-");
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        executor.initialize();
        return executor;
    }
}

protocol-buffers

https://developers.google.com/protocol-buffers

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