| /* |
| * Copyright 2015, Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| package io.grpc.internal; |
| |
| import com.google.common.base.Preconditions; |
| import io.grpc.Attributes; |
| import io.grpc.NameResolverProvider; |
| import java.net.URI; |
| |
| /** |
| * A provider for {@link DnsNameResolver}. |
| * |
| * <p>It resolves a target URI whose scheme is {@code "dns"}. The (optional) authority of the target |
| * URI is reserved for the address of alternative DNS server (not implemented yet). The path of the |
| * target URI, excluding the leading slash {@code '/'}, is treated as the host name and the optional |
| * port to be resolved by DNS. Example target URIs: |
| * |
| * <ul> |
| * <li>{@code "dns:///foo.googleapis.com:8080"} (using default DNS)</li> |
| * <li>{@code "dns://8.8.8.8/foo.googleapis.com:8080"} (using alternative DNS (not implemented |
| * yet))</li> |
| * <li>{@code "dns:///foo.googleapis.com"} (without port)</li> |
| * </ul> |
| */ |
| public final class DnsNameResolverProvider extends NameResolverProvider { |
| |
| private static final String SCHEME = "dns"; |
| |
| @Override |
| public DnsNameResolver newNameResolver(URI targetUri, Attributes params) { |
| if (SCHEME.equals(targetUri.getScheme())) { |
| String targetPath = Preconditions.checkNotNull(targetUri.getPath(), "targetPath"); |
| Preconditions.checkArgument(targetPath.startsWith("/"), |
| "the path component (%s) of the target (%s) must start with '/'", targetPath, targetUri); |
| String name = targetPath.substring(1); |
| return new DnsNameResolver(targetUri.getAuthority(), name, params, GrpcUtil.TIMER_SERVICE, |
| GrpcUtil.SHARED_CHANNEL_EXECUTOR); |
| } else { |
| return null; |
| } |
| } |
| |
| @Override |
| public String getDefaultScheme() { |
| return SCHEME; |
| } |
| |
| @Override |
| protected boolean isAvailable() { |
| return true; |
| } |
| |
| @Override |
| protected int priority() { |
| return 5; |
| } |
| } |