io.grpc.NameResolverProvider Maven / Gradle / Ivy
/*
* Copyright 2016 The gRPC 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 io.grpc;
import java.util.List;
/**
* Provider of name resolvers for name agnostic consumption.
*
* Implementations should not throw. If they do, it may interrupt class loading. If
* exceptions may reasonably occur for implementation-specific reasons, implementations should
* generally handle the exception gracefully and return {@code false} from {@link #isAvailable()}.
*/
@ExperimentalApi("https://github.com/grpc/grpc-java/issues/4159")
public abstract class NameResolverProvider extends NameResolver.Factory {
/**
* The port number used in case the target or the underlying naming system doesn't provide a
* port number.
*
* @since 1.0.0
*/
@SuppressWarnings("unused") // Avoids outside callers accidentally depending on the super class.
@Deprecated
public static final Attributes.Key PARAMS_DEFAULT_PORT =
NameResolver.Factory.PARAMS_DEFAULT_PORT;
/**
* Returns non-{@code null} ClassLoader-wide providers, in preference order.
*
* @since 1.0.0
* @deprecated Has no replacement
*/
@Deprecated
public static List providers() {
return NameResolverRegistry.getDefaultRegistry().providers();
}
/**
* @since 1.0.0
* @deprecated Use NameResolverRegistry.getDefaultRegistry().asFactory()
*/
@Deprecated
public static NameResolver.Factory asFactory() {
return NameResolverRegistry.getDefaultRegistry().asFactory();
}
/**
* Whether this provider is available for use, taking the current environment into consideration.
* If {@code false}, no other methods are safe to be called.
*
* @since 1.0.0
*/
protected abstract boolean isAvailable();
/**
* A priority, from 0 to 10 that this provider should be used, taking the current environment into
* consideration. 5 should be considered the default, and then tweaked based on environment
* detection. A priority of 0 does not imply that the provider wouldn't work; just that it should
* be last in line.
*
* @since 1.0.0
*/
protected abstract int priority();
}