1 files changed, 116 insertions, 0 deletions
diff --git a/src/javax/jmdns/impl/tasks/resolver/DNSResolverTask.java b/src/javax/jmdns/impl/tasks/resolver/DNSResolverTask.java
new file mode 100644
index 0000000..7fa7abb
--- /dev/null
+++ b/src/javax/jmdns/impl/tasks/resolver/DNSResolverTask.java
@@ -0,0 +1,116 @@
+// Licensed under Apache License version 2.0
+package javax.jmdns.impl.tasks.resolver;
+
+import java.io.IOException;
+import java.util.Timer;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.jmdns.impl.DNSOutgoing;
+import javax.jmdns.impl.JmDNSImpl;
+import javax.jmdns.impl.constants.DNSConstants;
+import javax.jmdns.impl.tasks.DNSTask;
+
+/**
+ * This is the root class for all resolver tasks.
+ * 
+ * @author Pierre Frisch
+ */
+public abstract class DNSResolverTask extends DNSTask {
+    private static Logger logger = Logger.getLogger(DNSResolverTask.class.getName());
+
+    /**
+     * Counts the number of queries being sent.
+     */
+    protected int         _count = 0;
+
+    /**
+     * @param jmDNSImpl
+     */
+    public DNSResolverTask(JmDNSImpl jmDNSImpl) {
+        super(jmDNSImpl);
+    }
+
+    /*
+     * (non-Javadoc)
+     * @see java.lang.Object#toString()
+     */
+    @Override
+    public String toString() {
+        return super.toString() + " count: " + _count;
+    }
+
+    /*
+     * (non-Javadoc)
+     * @see javax.jmdns.impl.tasks.DNSTask#start(java.util.Timer)
+     */
+    @Override
+    public void start(Timer timer) {
+        if (!this.getDns().isCanceling() && !this.getDns().isCanceled()) {
+            timer.schedule(this, DNSConstants.QUERY_WAIT_INTERVAL, DNSConstants.QUERY_WAIT_INTERVAL);
+        }
+    }
+
+    /*
+     * (non-Javadoc)
+     * @see java.util.TimerTask#run()
+     */
+    @Override
+    public void run() {
+        try {
+            if (this.getDns().isCanceling() || this.getDns().isCanceled()) {
+                this.cancel();
+            } else {
+                if (_count++ < 3) {
+                    if (logger.isLoggable(Level.FINER)) {
+                        logger.finer(this.getName() + ".run() JmDNS " + this.description());
+                    }
+                    DNSOutgoing out = new DNSOutgoing(DNSConstants.FLAGS_QR_QUERY);
+                    out = this.addQuestions(out);
+                    if (this.getDns().isAnnounced()) {
+                        out = this.addAnswers(out);
+                    }
+                    if (!out.isEmpty()) {
+                        this.getDns().send(out);
+                    }
+                } else {
+                    // After three queries, we can quit.
+                    this.cancel();
+                }
+            }
+        } catch (Throwable e) {
+            logger.log(Level.WARNING, this.getName() + ".run() exception ", e);
+            this.getDns().recover();
+        }
+    }
+
+    /**
+     * Overridden by subclasses to add questions to the message.<br/>
+     * <b>Note:</b> Because of message size limitation the returned message may be different than the message parameter.
+     * 
+     * @param out
+     *            outgoing message
+     * @return the outgoing message.
+     * @exception IOException
+     */
+    protected abstract DNSOutgoing addQuestions(DNSOutgoing out) throws IOException;
+
+    /**
+     * Overridden by subclasses to add questions to the message.<br/>
+     * <b>Note:</b> Because of message size limitation the returned message may be different than the message parameter.
+     * 
+     * @param out
+     *            outgoing message
+     * @return the outgoing message.
+     * @exception IOException
+     */
+    protected abstract DNSOutgoing addAnswers(DNSOutgoing out) throws IOException;
+
+    /**
+     * Returns a description of the resolver for debugging
+     * 
+     * @return resolver description
+     */
+    protected abstract String description();
+
+}