类签名：public abstract class StorageComponent extends Component
父类 Component
/**
* Components are object graphs used to compose a zipkin service or client. For example, a storage
* component might return a query api.
*
* <p>Components are lazy with regards to I/O. They can be injected directly to other components so
* as to avoid crashing the application graph if a network service is unavailable.
*/
public abstract class Component implements Closeable {
/**
* Answers the question: Are operations on this component likely to succeed?
*
* <p>Implementations should initialize the component if necessary. It should test a remote
* connection, or consult a trusted source to derive the result. They should use least resources
* possible to establish a meaningful result, and be safe to call many times, even concurrently.
* 测试数据来源的正确性
* @see CheckResult#OK
*/
public CheckResult check() {
return CheckResult.OK;
}
/**
* Closes any network resources created implicitly by the component.
*
* <p>For example, if this created a connection, it would close it. If it was provided one, this
* would close any sessions, but leave the connection open.
* 关闭各种资源，如果是连接，需要关闭该连接打开的会话而不是连接本身
*/
@Override public void close() throws IOException {
}
}