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      1 // Copyright 2003-2005 Arthur van Hoff, Rick Blair
      2 // Licensed under Apache License version 2.0
      3 // Original license LGPL
      4 
      5 package javax.jmdns.impl.tasks.resolver;
      6 
      7 import java.io.IOException;
      8 
      9 import javax.jmdns.impl.DNSOutgoing;
     10 import javax.jmdns.impl.DNSQuestion;
     11 import javax.jmdns.impl.DNSRecord;
     12 import javax.jmdns.impl.JmDNSImpl;
     13 import javax.jmdns.impl.ServiceInfoImpl;
     14 import javax.jmdns.impl.constants.DNSRecordClass;
     15 import javax.jmdns.impl.constants.DNSRecordType;
     16 
     17 /**
     18  * The ServiceInfoResolver queries up to three times consecutively for a service info, and then removes itself from the timer.
     19  * <p/>
     20  * The ServiceInfoResolver will run only if JmDNS is in state ANNOUNCED. REMIND: Prevent having multiple service resolvers for the same info in the timer queue.
     21  */
     22 public class ServiceInfoResolver extends DNSResolverTask {
     23 
     24     private final ServiceInfoImpl _info;
     25 
     26     public ServiceInfoResolver(JmDNSImpl jmDNSImpl, ServiceInfoImpl info) {
     27         super(jmDNSImpl);
     28         this._info = info;
     29         info.setDns(this.getDns());
     30         this.getDns().addListener(info, DNSQuestion.newQuestion(info.getQualifiedName(), DNSRecordType.TYPE_ANY, DNSRecordClass.CLASS_IN, DNSRecordClass.NOT_UNIQUE));
     31     }
     32 
     33     /*
     34      * (non-Javadoc)
     35      * @see javax.jmdns.impl.tasks.DNSTask#getName()
     36      */
     37     @Override
     38     public String getName() {
     39         return "ServiceInfoResolver(" + (this.getDns() != null ? this.getDns().getName() : "") + ")";
     40     }
     41 
     42     /*
     43      * (non-Javadoc)
     44      * @see java.util.TimerTask#cancel()
     45      */
     46     @Override
     47     public boolean cancel() {
     48         // We should not forget to remove the listener
     49         boolean result = super.cancel();
     50         if (!_info.isPersistent()) {
     51             this.getDns().removeListener(_info);
     52         }
     53         return result;
     54     }
     55 
     56     /*
     57      * (non-Javadoc)
     58      * @see javax.jmdns.impl.tasks.Resolver#addAnswers(javax.jmdns.impl.DNSOutgoing)
     59      */
     60     @Override
     61     protected DNSOutgoing addAnswers(DNSOutgoing out) throws IOException {
     62         DNSOutgoing newOut = out;
     63         if (!_info.hasData()) {
     64             long now = System.currentTimeMillis();
     65             newOut = this.addAnswer(newOut, (DNSRecord) this.getDns().getCache().getDNSEntry(_info.getQualifiedName(), DNSRecordType.TYPE_SRV, DNSRecordClass.CLASS_IN), now);
     66             newOut = this.addAnswer(newOut, (DNSRecord) this.getDns().getCache().getDNSEntry(_info.getQualifiedName(), DNSRecordType.TYPE_TXT, DNSRecordClass.CLASS_IN), now);
     67             if (_info.getServer().length() > 0) {
     68                 newOut = this.addAnswer(newOut, (DNSRecord) this.getDns().getCache().getDNSEntry(_info.getServer(), DNSRecordType.TYPE_A, DNSRecordClass.CLASS_IN), now);
     69                 newOut = this.addAnswer(newOut, (DNSRecord) this.getDns().getCache().getDNSEntry(_info.getServer(), DNSRecordType.TYPE_AAAA, DNSRecordClass.CLASS_IN), now);
     70             }
     71         }
     72         return newOut;
     73     }
     74 
     75     /*
     76      * (non-Javadoc)
     77      * @see javax.jmdns.impl.tasks.Resolver#addQuestions(javax.jmdns.impl.DNSOutgoing)
     78      */
     79     @Override
     80     protected DNSOutgoing addQuestions(DNSOutgoing out) throws IOException {
     81         DNSOutgoing newOut = out;
     82         if (!_info.hasData()) {
     83             newOut = this.addQuestion(newOut, DNSQuestion.newQuestion(_info.getQualifiedName(), DNSRecordType.TYPE_SRV, DNSRecordClass.CLASS_IN, DNSRecordClass.NOT_UNIQUE));
     84             newOut = this.addQuestion(newOut, DNSQuestion.newQuestion(_info.getQualifiedName(), DNSRecordType.TYPE_TXT, DNSRecordClass.CLASS_IN, DNSRecordClass.NOT_UNIQUE));
     85             if (_info.getServer().length() > 0) {
     86                 newOut = this.addQuestion(newOut, DNSQuestion.newQuestion(_info.getServer(), DNSRecordType.TYPE_A, DNSRecordClass.CLASS_IN, DNSRecordClass.NOT_UNIQUE));
     87                 newOut = this.addQuestion(newOut, DNSQuestion.newQuestion(_info.getServer(), DNSRecordType.TYPE_AAAA, DNSRecordClass.CLASS_IN, DNSRecordClass.NOT_UNIQUE));
     88             }
     89         }
     90         return newOut;
     91     }
     92 
     93     /*
     94      * (non-Javadoc)
     95      * @see javax.jmdns.impl.tasks.Resolver#description()
     96      */
     97     @Override
     98     protected String description() {
     99         return "querying service info: " + (_info != null ? _info.getQualifiedName() : "null");
    100     }
    101 
    102 }