Add smack-resolver-minidns

smack-resolver-minidns/build.gradle

@@ -0,0 +1,10 @@
+description = """\
+DNS SRV with minidns
+Use minidns for DNS SRV lookups. For platforms that don't provide the
+javax.naming API (e.g. Android)."""
+
+dependencies {
+	compile project(path: ':smack-core', configuration: 'dns')
+	compile 'de.measite.minidns:minidns:0.1.1'
+	compile "org.igniterealtime.jxmpp:jxmpp-util-cache:$jxmppVersion"
+}

smack-resolver-minidns/src/main/java/org/jivesoftware/smack/util/dns/minidns/MiniDnsResolver.java

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+/**
+ *
+ * Copyright 2014 Florian Schmaus
+ *
+ * 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 org.jivesoftware.smack.util.dns.minidns;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import org.jivesoftware.smack.util.dns.DNSResolver;
+import org.jivesoftware.smack.util.dns.SRVRecord;
+import org.jxmpp.util.cache.ExpirationCache;
+
+import de.measite.minidns.Client;
+import de.measite.minidns.DNSCache;
+import de.measite.minidns.DNSMessage;
+import de.measite.minidns.Question;
+import de.measite.minidns.Record;
+import de.measite.minidns.Record.CLASS;
+import de.measite.minidns.Record.TYPE;
+import de.measite.minidns.record.SRV;
+
+
+/**
+ * This implementation uses the <a href="https://github.com/rtreffer/minidns/">minidns</a> implementation for
+ * resolving DNS addresses.
+ */
+public class MiniDnsResolver implements DNSResolver {
+
+    private static final long ONE_DAY = 24*60*60*1000;
+    private static final MiniDnsResolver instance = new MiniDnsResolver();
+    private static final ExpirationCache<Question, DNSMessage> cache = new ExpirationCache<Question, DNSMessage>(10, ONE_DAY);
+    private final Client client; 
+
+    private MiniDnsResolver() {
+        client = new Client(new DNSCache() {
+
+            @Override
+            public DNSMessage get(Question question) {
+                return cache.get(question);
+            }
+
+            @Override
+            public void put(Question question, DNSMessage message) {
+                long expirationTime = ONE_DAY;
+                for (Record record : message.getAnswers()) {
+                    if (record.isAnswer(question)) {
+                        expirationTime = record.getTtl();
+                        break;
+                    }
+                }
+                cache.put(question, message, expirationTime);
+            }
+
+        });
+    }
+
+    public static DNSResolver getInstance() {
+        return instance;
+    }
+
+    @Override
+    public List<SRVRecord> lookupSRVRecords(String name) {
+        List<SRVRecord> res = new LinkedList<SRVRecord>();
+        DNSMessage message = client.query(name, TYPE.SRV, CLASS.IN);
+        for (Record record : message.getAnswers()) {
+            SRV srv = (SRV) record.getPayload();
+            res.add(new SRVRecord(srv.getName(), srv.getPort(), srv.getPriority(), srv.getWeight()));
+        }
+        return res;
+    }
+}