io.atlasmap.xml.core.XmlFieldReader Maven / Gradle / Ivy

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/**
 * Copyright (C) 2017 Red Hat, Inc.
 *
 * 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 io.atlasmap.xml.core;

import java.io.ByteArrayInputStream;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Optional;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

import io.atlasmap.api.AtlasConversionException;
import io.atlasmap.api.AtlasException;
import io.atlasmap.core.AtlasUtil;
import io.atlasmap.spi.AtlasConversionService;
import io.atlasmap.spi.AtlasFieldReader;
import io.atlasmap.spi.AtlasInternalSession;
import io.atlasmap.v2.AtlasMapping;
import io.atlasmap.v2.AtlasModelFactory;
import io.atlasmap.v2.AuditStatus;
import io.atlasmap.v2.CollectionType;
import io.atlasmap.v2.DataSource;
import io.atlasmap.v2.DataSourceType;
import io.atlasmap.v2.Field;
import io.atlasmap.v2.FieldGroup;
import io.atlasmap.v2.FieldType;
import io.atlasmap.xml.core.XmlPath.XmlSegmentContext;
import io.atlasmap.xml.v2.XmlDataSource;
import io.atlasmap.xml.v2.XmlField;
import io.atlasmap.xml.v2.XmlNamespace;
import io.atlasmap.xml.v2.XmlNamespaces;

public class XmlFieldReader extends XmlFieldTransformer implements AtlasFieldReader {

    private static final Logger LOG = LoggerFactory.getLogger(XmlFieldReader.class);

    private AtlasConversionService conversionService;
    private Document document;

    public XmlFieldReader(ClassLoader cl, AtlasConversionService conversionService) {
        super(cl);
        this.conversionService = conversionService;
    }

    public XmlFieldReader(ClassLoader cl, AtlasConversionService conversionService, Map namespaces) {
        super(cl, namespaces);
        this.conversionService = conversionService;
    }

    public Field read(AtlasInternalSession session) throws AtlasException {
        Field field = session.head().getSourceField();
        if (document == null) {
            AtlasUtil.addAudit(session, field.getDocId(),
                    String.format("Cannot read field '%s' of document '%s', document is null",
                            field.getPath(), field.getDocId()),
                    field.getPath(), AuditStatus.ERROR, null);
            return field;
        }
        if (field == null) {
            throw new AtlasException(new IllegalArgumentException("Argument 'field' cannot be null"));
        }

        seedDocumentNamespaces(document);
        XmlField xmlField = XmlField.class.cast(field);

        if (LOG.isDebugEnabled()) {
            LOG.debug("Reading source value for field: " + xmlField.getPath());
        }
        Optional xmlNamespaces = getSourceNamespaces(session, xmlField);
        XmlSegmentContext lastSegment = null;
        List parentNodes = Arrays.asList(document.getDocumentElement());
        XmlPath path = new XmlPath(xmlField.getPath());
        for (XmlSegmentContext sc : path.getXmlSegments(false)) {
            lastSegment = sc;
            if (LOG.isDebugEnabled()) {
                LOG.debug("Now processing segment: " + sc.getName());
            }
            if (path.getParentSegmentOf(sc) == null || path.getParentSegmentOf(sc).isRoot()) {
                if (LOG.isDebugEnabled()) {
                    LOG.debug("Skipping root segment: " + sc);
                }
                // processing root node part of path such as the "XOA" part of
                // "/XOA/contact<>/firstName", skip.
                continue;
            }
            parentNodes = extractSegment(parentNodes, sc, xmlNamespaces);
        }
        if (lastSegment != null) {
            readValue(session, parentNodes, lastSegment, xmlField);
        }
        return session.head().getSourceField();
    }

    private List extractSegment(List parentNodes, XmlSegmentContext sc, Optional xmlNamespaces) throws AtlasException {
        List answer = new LinkedList<>();
        for (Element parentNode : parentNodes) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Parent element is currently: " + xmlHelper.writeDocumentToString(true, parentNode));
            }
            if (sc.isAttribute()) {
                answer.add(parentNode);
                continue;
            }

            String childrenElementName = sc.getName();
            String namespaceAlias = sc.getNamespace();
            Optional namespace = getNamespace(xmlNamespaces, namespaceAlias);
            if (LOG.isDebugEnabled()) {
                LOG.debug("Looking for children elements with name: " + childrenElementName);
            }
            List children = XmlIOHelper.getChildrenWithNameStripAlias(childrenElementName, namespace, parentNode);
            if (children == null || children.isEmpty()) {
                if (LOG.isDebugEnabled()) {
                    LOG.debug("Skipping source value set, couldn't find children with name '" + childrenElementName
                            + "', for segment: " + sc);
                }
                continue;
            }
            if (sc.getCollectionType() != CollectionType.NONE) {
                Integer index = sc.getCollectionIndex();
                if (index == null) {
                    // TODO process collection
                    answer.addAll(children);
                    continue;
                }
                if (index >= children.size()) {
                    if (LOG.isDebugEnabled()) {
                        LOG.debug("Skipping source value set, children list can't fit index " + index
                                + ", children list size: " + children.size());
                    }
                    continue;
                }
                answer.add(children.get(index));
            } else {
                answer.add(children.get(0));
            }
        }
        return answer;
    }

    private void readValue(AtlasInternalSession session, List parentNodes, XmlSegmentContext sc, XmlField xmlField) {
        if (xmlField.getFieldType() == null) {
            xmlField.setFieldType(FieldType.STRING);
        }

        XmlPath path = new XmlPath(xmlField.getPath());
        FieldGroup fieldGroup = null;
        if (path.hasCollection() && !path.isIndexedCollection()) {
            fieldGroup = AtlasModelFactory.createFieldGroupFrom(xmlField);
            session.head().setSourceField(fieldGroup);
        }

        for (int i=0; i getSourceNamespaces(AtlasInternalSession session, XmlField xmlField) {
        DataSource dataSource = null;
        AtlasMapping mapping = session.getMapping();
        // this is to simplify tests which uses mocks
        if (mapping == null || mapping.getDataSource() == null || xmlField.getDocId() == null) {
            return Optional.empty();
        }
        List dataSources = mapping.getDataSource();
        for (DataSource source : dataSources) {
            if (!source.getDataSourceType().equals(DataSourceType.SOURCE)) {
                continue;
            }
            if (xmlField.getDocId().equals(source.getId())) {
                dataSource = source;
                break;
            }
        }
        if (dataSource == null || !XmlDataSource.class.isInstance(dataSource)) {
            return Optional.empty();
        }
        XmlDataSource xmlDataSource = XmlDataSource.class.cast(dataSource);
        return Optional.of(xmlDataSource.getXmlNamespaces());
    }

    private Optional getNamespace(Optional xmlNamespaces, String namespaceAlias) {
        Optional namespace = Optional.empty();
        if (xmlNamespaces.isPresent()) {
            for (XmlNamespace xmlNamespace : xmlNamespaces.get().getXmlNamespace()) {
                if (xmlNamespace.getAlias().equals(namespaceAlias)) {
                    namespace = Optional.of(xmlNamespace.getUri());
                    break;
                }
            }
        }
        return namespace;
    }

}