zipkin2.Component Maven / Gradle / Ivy
/*
* Copyright 2015-2019 The OpenZipkin Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package zipkin2;
import java.io.Closeable;
import java.io.IOException;
/**
* Components are object graphs used to compose a zipkin service or client. For example, a storage
* component might return a query api.
*
* 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?
*
*
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.
*
* @see CheckResult#OK
*/
public CheckResult check() {
return CheckResult.OK;
}
/**
* Closes any network resources created implicitly by the component.
*
*
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.
*/
@Override public void close() throws IOException {
}
}