Spring Boot 3.5.3新特性解析及JDK21集成实战应用

# 启用虚拟线程（需JDK21+）
spring.threads.virtual.enabled=true

@Bean
public TaskDecorator mdcPropagator() {
  return task -> {
    Map<String, String> contextMap = MDC.getCopyOfContextMap(); // 捕获日志上下文
    return () -> {
      MDC.setContextMap(contextMap);
      task.run();
      MDC.clear();
    };
  };
}

# 从环境变量APP_CONFIG加载配置
spring.config.import=env:APP_CONFIGURATION

# 启动命令注入配置
export APP_CONFIGURATION="OPENAI_KEY=sk-xxx"; java -jar app.jar

management:
  endpoints:
    web:
      exposure:
        include: "metrics,tls-certificates"

// 错误示例：前缀重叠导致启动失败
@ConfigurationProperties(prefix = "app.api") 
public class ApiProps { /* ... */ }
@ConfigurationProperties(prefix = "app.api.client") // 冲突！
public class ClientProps { /* ... */ }
// 正确做法：嵌套类统一管理
@ConfigurationProperties(prefix = "app.api")
public class ApiProps {
  private Client client;
  public static class Client { /* ... */ }
}

management:
  tracing:
    http:
      response:
        enabled: true  # 启用响应头注入TraceID

spring:
  data:
    redis:
      client:
        read-strategy: REPLICA_PREFERRED  # 优先读副本

<parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>3.5.3</version> <!-- 锁定版本 -->
</parent>

// 移除JUnit4依赖
@Test  // 原: org.junit.Test → 改为↓
import org.junit.jupiter.api.Test; 
// 无需@RunWith(SpringRunner.class)
@SpringBootTest
public class UserServiceTest { ... }