org.maodian.flyingcat.xmpp.codec.AbstractCodec.java Source code

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Here is the source code for org.maodian.flyingcat.xmpp.codec.AbstractCodec.java

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/*
 * Copyright 2013 - 2013 Cole Wen
 *
 * 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.maodian.flyingcat.xmpp.codec;

import javax.inject.Inject;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;

import org.apache.commons.lang3.StringUtils;
import org.maodian.flyingcat.xmpp.GlobalContext;
import org.maodian.flyingcat.xmpp.entity.Stanzas;
import org.maodian.flyingcat.xmpp.state.StanzaError;
import org.maodian.flyingcat.xmpp.state.StanzaError.Type;
import org.maodian.flyingcat.xmpp.state.StanzaErrorCondition;
import org.maodian.flyingcat.xmpp.state.StreamError;
import org.maodian.flyingcat.xmpp.state.XmppException;

/**
 * @author Cole Wen
 *
 */
public abstract class AbstractCodec implements Decoder, Encoder {
    private GlobalContext applicationContext;

    protected Decoder findDecoder(QName key, Stanzas stanzas) {
        Decoder decoder = applicationContext.getDecoder(key);
        //TODO: here we should distinguish service_unavailable and feature_not_implemented
        if (decoder == null) {
            throw new XmppException("Cant find Decoder for:" + key.toString(),
                    new StanzaError(stanzas, StanzaErrorCondition.SERVICE_UNAVAILABLE, Type.CANCEL));
        }
        return decoder;
    }

    protected Encoder findEncoder(Class<?> key) {
        Encoder encoder = applicationContext.getEncoder(key);
        if (encoder == null) {
            throw new XmppException(StreamError.INTERNAL_SERVER_ERROR);
        }
        return encoder;
    }

    protected void writeAttributeIfNotBlank(XMLStreamWriter xmlsw, String localName, String value)
            throws XMLStreamException {
        if (StringUtils.isNotBlank(value)) {
            xmlsw.writeAttribute(localName, value);
        }
    }

    protected void writeAttributeIfNotBlank(XMLStreamWriter xmlsw, String prefix, String namespaceURI,
            String localName, String value) throws XMLStreamException {
        if (StringUtils.isNotBlank(value)) {
            xmlsw.writeAttribute(prefix, namespaceURI, localName, value);
        }
    }

    protected void writeRequiredAttribute(XMLStreamWriter xmlsw, String localName, String value)
            throws XMLStreamException {
        if (StringUtils.isBlank(value)) {
            throw new XmppException(StreamError.INTERNAL_SERVER_ERROR);
        }
        xmlsw.writeAttribute(localName, value);
    }

    protected void writeRequiredAttribute(XMLStreamWriter xmlsw, String prefix, String namespaceURI,
            String localName, String value) throws XMLStreamException {
        if (StringUtils.isBlank(value)) {
            throw new XmppException(StreamError.INTERNAL_SERVER_ERROR);
        }
        xmlsw.writeAttribute(prefix, namespaceURI, localName, value);
    }

    @Inject
    void setApplicationContext(GlobalContext applicationContext) {
        this.applicationContext = applicationContext;
    }
}