StaxNavBuilderImpl.java

/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2011, Red Hat, Inc., and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.gatein.common.xml.stax.navigator.builder;

import java.io.InputStream;
import java.io.Reader;
import java.util.HashMap;
import java.util.Map;

import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.transform.Source;

import org.staxnav.Naming;
import org.staxnav.StaxNavException;
import org.staxnav.StaxNavigator;
import org.staxnav.StaxNavigatorFactory;

/**
 * @author <a href="mailto:nscavell@redhat.com">Nick Scavelli</a>
 * @version $Revision$
 */
public class StaxNavBuilderImpl implements StaxNavBuilder {
    private Object input;
    private String inputEncoding;
    private XMLStreamReader reader;

    private Map<String, Object> properties = new HashMap<String, Object>();
    private Map<String, Object> supportedProperties = new HashMap<String, Object>();

    @Override
    public StaxNavBuilder withProperty(String name, Object value) {
        if (name == null)
            throw new IllegalArgumentException("name is null");
        if (value == null)
            throw new IllegalArgumentException("value is null");

        properties.put(name, value);
        return this;
    }

    @Override
    public StaxNavBuilder withPropertyIfSupported(String name, Object value) {
        if (name == null)
            throw new IllegalArgumentException("name is null");
        if (value == null)
            throw new IllegalArgumentException("value is null");

        supportedProperties.put(name, value);
        return this;
    }

    @Override
    public StaxNavBuilder withInputStream(InputStream inputStream) {
        if (inputStream == null)
            throw new IllegalArgumentException("inputStream is null");

        input = inputStream;
        return this;
    }

    @Override
    public StaxNavBuilder withInputStream(InputStream inputStream, String encoding) {
        if (inputStream == null)
            throw new IllegalArgumentException("inputStream is null");
        if (encoding == null)
            throw new IllegalArgumentException("encoding is null");

        input = inputStream;
        inputEncoding = encoding;
        return this;
    }

    @Override
    public StaxNavBuilder withReader(Reader reader) {
        if (reader == null)
            throw new IllegalArgumentException("reader is null");

        this.input = reader;
        return this;
    }

    @Override
    public StaxNavBuilder withSource(Source source) {
        if (source == null)
            throw new IllegalArgumentException("source is null");

        input = source;
        return this;
    }

    @Override
    public StaxNavBuilder withXmlStreamReader(XMLStreamReader reader) {
        if (reader == null)
            throw new IllegalArgumentException("reader is null");

        this.reader = reader;
        return this;
    }

    @Override
    public <N> StaxNavigator<N> build(Naming<N> naming) throws StaxNavException, IllegalStateException {
        if (naming == null)
            throw new IllegalArgumentException("naming is null");

        if (reader == null && input == null)
            throw new IllegalStateException(
                    "Cannot build stax reader. Try calling withInputStream/withReader or pass in own XMLStreamReader.");

        if (reader == null) {
            // TODO: Create solution to properly cache XMLInputFactory
            XMLInputFactory factory = XMLInputFactory.newInstance();

            // Set properties
            for (Map.Entry<String, Object> entry : properties.entrySet()) {
                factory.setProperty(entry.getKey(), entry.getValue());
            }

            // Set properties if supported
            for (Map.Entry<String, Object> entry : supportedProperties.entrySet()) {
                String name = entry.getKey();
                if (factory.isPropertySupported(name)) {
                    factory.setProperty(name, entry.getValue());
                }
            }

            if (input instanceof InputStream) {
                if (inputEncoding == null) {
                    try {
                        reader = factory.createXMLStreamReader((InputStream) input, inputEncoding);
                    } catch (XMLStreamException e) {
                        throw new StaxNavException(e);
                    }
                } else {
                    try {
                        reader = factory.createXMLStreamReader((InputStream) input);
                    } catch (XMLStreamException e) {
                        throw new StaxNavException(null, "Exception creating XMLStreamReader with inputStream: " + input, e);
                    }
                }
            } else if (input instanceof Reader) {
                try {
                    reader = factory.createXMLStreamReader((Reader) input);
                } catch (XMLStreamException e) {
                    throw new StaxNavException(null, "Exception creating XMLStreamReader with reader: " + input, e);
                }
            } else if (input instanceof Source) {
                try {
                    reader = factory.createXMLStreamReader((Source) input);
                } catch (XMLStreamException e) {
                    throw new StaxNavException(null, "Exception creating XMLStreamReader with Source: " + input, e);
                }
            } else {
                throw new IllegalStateException("Unknown input: " + input); // should never happen...
            }
        }

        return StaxNavigatorFactory.create(naming, reader);
    }
}