resolver/src/main/java/org/apache/james/jspf/impl/DNSJnioAsynchService.java

/****************************************************************
 * 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.james.jspf.impl;

import java.util.List;

import org.apache.james.jspf.core.DNSRequest;
import org.apache.james.jspf.core.exceptions.TimeoutException;
import org.apache.james.jspf.executor.DNSAsynchLookupService;
import org.apache.james.jspf.executor.IResponse;
import org.apache.james.jspf.executor.IResponseQueue;
import org.xbill.DNS.DClass;
import org.xbill.DNS.Message;
import org.xbill.DNS.Name;
import org.xbill.DNS.Record;
import org.xbill.DNS.Resolver;
import org.xbill.DNS.TextParseException;
import org.xbill.DNS.Type;

import uk.nominet.dnsjnio.ExtendedNonblockingResolver;
import uk.nominet.dnsjnio.LookupAsynch;

public class DNSJnioAsynchService implements DNSAsynchLookupService {

    private ExtendedNonblockingResolver resolver;

    public DNSJnioAsynchService(ExtendedNonblockingResolver resolver) {
        this.resolver = resolver;
        LookupAsynch.setDefaultResolver(resolver);
    }
    
    /**
     * Set the timeout for the resolvers
     * @param timeout
     */
    public synchronized void setTimeout(int timeout) {
        Resolver[] res = resolver.getResolvers();
        for (int i = 0; i < res.length; i++) {
            res[i].setTimeout(timeout);
        }
    }
    
    /**
     * @see org.apache.james.jspf.executor.DNSAsynchLookupService#getRecordsAsynch(org.apache.james.jspf.core.DNSRequest, int, org.apache.james.jspf.executor.IResponseQueue)
     */
    public void getRecordsAsynch(DNSRequest request, int id,
            IResponseQueue responsePool) {
        
        Message message;
        try {
            message = makeQuery(request, id);
            LookupAsynch la = new LookupAsynch(message.getQuestion().getName(), message.getQuestion().getType());
            la.runAsynch(new Runnable() {

                private IResponseQueue responsePool;
                private Integer id;
                private LookupAsynch lookup;

                public void run() {
                    responsePool.insertResponse(new IResponse() {

                        public Exception getException() {
                            if (lookup.getResult() == LookupAsynch.TRY_AGAIN) {
                                return new TimeoutException(lookup.getErrorString());
                            } else {
                                return null;
                            }
                        }

                        public Object getId() {
                            return id;
                        }

                        public List<String> getValue() {
                            return (DNSServiceXBillImpl.convertRecordsToList(lookup.getAnswers()));
                        }
                        
                    });
                }

                public Runnable setResponsePool(LookupAsynch la, IResponseQueue responsePool,
                        Integer integer) {
                    this.lookup = la;
                    this.responsePool = responsePool;
                    this.id = integer;
                    return this;
                }
                
            }.setResponsePool(la, responsePool, new Integer(id)));
            // this.resolver.sendAsync(message, new Integer(id), new ResponseQueueAdaptor(responsePool));
        } catch (TextParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    private Message makeQuery(DNSRequest request, int id) throws TextParseException {
        Name name = Name.fromString(request.getHostname(), Name.root);
        
        int type;
        switch (request.getRecordType()) {
            case DNSRequest.A: type = Type.A; break;
            case DNSRequest.AAAA: type = Type.AAAA; break;
            case DNSRequest.MX: type = Type.MX; break;
            case DNSRequest.PTR: type = Type.PTR; break;
            case DNSRequest.SPF: type = Type.SPF; break;
            case DNSRequest.TXT: type = Type.TXT; break;
            default: 
                throw new UnsupportedOperationException("Unknown query type: "+request.getRecordType());
        }
        
        Record question = Record.newRecord(name, type, DClass.ANY);
        Message query = Message.newQuery(question);
        query.getHeader().setID(id);
        return query;
    }
}