Adding missed file for HDFS-2450 commit

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20-security@1190100 13f79535-47bb-0310-9956-ffa450edef68

src/test/org/apache/hadoop/net/NetUtilsTestResolver.java

@@ -0,0 +1,74 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.hadoop.net;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.hadoop.net.NetUtils.QualifiedHostResolver;
+
+/**
+ * provides a dummy dns search resolver with a configurable search path
+ * and host mapping
+ */
+public class NetUtilsTestResolver extends QualifiedHostResolver {
+  Map<String, InetAddress> resolvedHosts = new HashMap<String, InetAddress>();
+  List<String> hostSearches = new LinkedList<String>();
+
+  public static NetUtilsTestResolver install() {
+    NetUtilsTestResolver resolver = new NetUtilsTestResolver();
+    resolver.setSearchDomains("a.b", "b", "c");
+    resolver.addResolvedHost("host.a.b.", "1.1.1.1");
+    resolver.addResolvedHost("b-host.b.", "2.2.2.2");
+    resolver.addResolvedHost("simple.", "3.3.3.3");    
+    NetUtils.setHostResolver(resolver);
+    return resolver;
+  }
+
+  public void addResolvedHost(String host, String ip) {
+    InetAddress addr;
+    try {
+      addr = InetAddress.getByName(ip);
+      addr = InetAddress.getByAddress(host, addr.getAddress());
+    } catch (UnknownHostException e) {
+      throw new IllegalArgumentException("not an ip:"+ip);
+    }
+    resolvedHosts.put(host, addr);
+  }
+
+  InetAddress getInetAddressByName(String host) throws UnknownHostException {
+    hostSearches.add(host);
+    if (!resolvedHosts.containsKey(host)) {
+      throw new UnknownHostException(host);
+    }
+    return resolvedHosts.get(host);
+  }
+
+  String[] getHostSearches() {
+    return hostSearches.toArray(new String[0]);
+  }
+
+  void reset() {
+    hostSearches.clear();
+  }
+}