org.arquillian.ape.rdbms.core.configuration.PersistenceDescriptorParser Maven / Gradle / Ivy

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 * Copyright 2011 Red Hat Inc. and/or its affiliates and other contributors
 * as indicated by the @authors tag. All rights reserved.
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 * full listing of individual contributors.
 *
 * 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
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package org.arquillian.ape.rdbms.core.configuration;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.Scanner;
import javax.xml.parsers.DocumentBuilderFactory;
import org.arquillian.ape.rdbms.core.exception.MultiplePersistenceUnitsException;
import org.arquillian.ape.rdbms.core.exception.PersistenceDescriptorParsingException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * @author Bartosz Majsak
 */
public class PersistenceDescriptorParser {

    private static final String JTA_DATA_SOURCE_TAG = "jta-data-source";

    private static final String NON_JTA_DATA_SOURCE_TAG = "non-jta-data-source";

    private final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

    public String obtainDataSourceName(final String descriptor) {
        Document document = parseXmlDescriptor(descriptor);
        final NodeList persistenceUnits = document.getElementsByTagName("persistence-unit");
        if (persistenceUnits.getLength() > 1) {
            throw new MultiplePersistenceUnitsException(
                "Multiple persistence units defined. Please specify default data source either in 'arquillian.xml' or by using @DataSource annotation");
        }
        final Node persistenceUnit = persistenceUnits.item(0);
        Node dataSource = getJtaDataSource(persistenceUnit);
        if (dataSource == null) {
            dataSource = getNonJtaDataSource(persistenceUnit);
        }
        return dataSource.getTextContent();
    }

    public String obtainDataSourceName(final InputStream inputStream) {
        return obtainDataSourceName(new Scanner(inputStream).useDelimiter("\\A").next());
    }

    private Document parseXmlDescriptor(final String descriptor) {
        try {
            return factory.newDocumentBuilder().parse(new ByteArrayInputStream(descriptor.getBytes()));
        } catch (Exception e) {
            throw new PersistenceDescriptorParsingException("Unable to parse descriptor " + descriptor, e);
        }
    }

    private Node getNonJtaDataSource(Node persistenceUnit) {
        return ((Element) persistenceUnit).getElementsByTagName(NON_JTA_DATA_SOURCE_TAG).item(0);
    }

    private Node getJtaDataSource(final Node persistenceUnit) {
        return ((Element) persistenceUnit).getElementsByTagName(JTA_DATA_SOURCE_TAG).item(0);
    }
}