SpringBoot项目启动速度深度优化指南

# 开启启动时间记录
spring.main.startup-time=true
# 输出详细的Bean创建耗时
logging.level.org.springframework.beans.factory.support.DefaultListableBeanFactory=DEBUG

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

management.endpoints.web.exposure.include=startup
management.endpoint.startup.enabled=true

<!-- 错误：引入了不必要的web依赖 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- 正确：只保留需要的依赖 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <!-- 排除不需要的传递依赖 -->
    <exclusions>
        <exclusion>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-undertow</artifactId>
</dependency>

@SpringBootApplication(
    exclude = {
        DataSourceAutoConfiguration.class,
        RedisAutoConfiguration.class,
        SecurityAutoConfiguration.class,
        ThymeleafAutoConfiguration.class,
        MailSenderAutoConfiguration.class
    }
)
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

java -jar app.jar --debug

# 禁用JMX自动配置
spring.jmx.enabled=false
# 禁用端点JMX暴露
management.endpoints.jmx.exposure.exclude=*

# 禁用Spring AOP自动代理（如果不使用AOP）
spring.aop.auto=false
# 禁用事务AOP（如果不使用声明式事务）
spring.transaction.auto=false

// 明确指定扫描的包，避免扫描无关目录
@SpringBootApplication(scanBasePackages = "com.company.project")
// 更精确：只扫描包含组件的包
@ComponentScan(basePackages = {
    "com.company.project.controller",
    "com.company.project.service",
    "com.company.project.mapper"
})

# 全局开启懒加载
spring.main.lazy-initialization=true

// 对单个Bean使用懒加载
@Service
@Lazy
public class HeavyService {
    // 耗时的初始化操作
}

// 对配置类中的所有Bean使用懒加载
@Configuration
@Lazy
public class HeavyConfig {
    @Bean
    public HeavyBean heavyBean() {
        return new HeavyBean();
    }
}

@Configuration
public class CriticalConfig {
    // 关键Bean不使用懒加载
    @Bean
    @Lazy(false)
    public DataSource dataSource() {
        return new HikariDataSource();
    }
}

// 错误：在@PostConstruct中执行耗时操作
@Service
public class BadService {
    @PostConstruct
    public void init() {
        // 耗时操作：加载大量数据、调用外部接口
        loadLargeData();
    }
}

// 正确：使用异步初始化
@Service
public class GoodService {
    @PostConstruct
    public void init() {
        CompletableFuture.runAsync(this::loadLargeData);
    }
    
    private void loadLargeData() {
        // 耗时操作
    }
}

@Component
@Order(1) // 高优先级，先执行
public class CriticalRunner implements CommandLineRunner {
    @Override
    public void run(String... args) throws Exception {
        // 关键初始化逻辑
    }
}

@Component
@Order(2)
public class NonCriticalRunner implements CommandLineRunner {
    @Autowired
    private TaskExecutor taskExecutor;
    
    @Override
    public void run(String... args) throws Exception {
        taskExecutor.execute(() -> {
            // 非关键初始化逻辑
        });
    }
}

java -jar \
  -XX:+UseG1GC \
  -XX:MaxGCPauseMillis=200 \
  -XX:+TieredCompilation \
  -XX:TieredStopAtLevel=1 \
  -Xms512m \
  -Xmx1024m \
  -XX:+UseStringDeduplication \
  -XX:+DisableAttachMechanism \
  app.jar

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

# 禁用模板引擎缓存
spring.thymeleaf.cache=false
spring.freemarker.cache=false
# 禁用静态资源缓存
spring.web.resources.cache.period=0
# 禁用Hibernate二级缓存
spring.jpa.properties.hibernate.cache.use_second_level_cache=false

module com.company.project {
    requires spring.boot;
    requires spring.boot.autoconfigure;
    requires spring.web;
    
    exports com.company.project;
}