hydrograph.ui.dataviewer.utilities.ViewDataSchemaHelper.java Source code

Introduction

Here is the source code for hydrograph.ui.dataviewer.utilities.ViewDataSchemaHelper.java

Source

/*******************************************************************************
 * Copyright 2017 Capital One Services, LLC and Bitwise, 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 hydrograph.ui.dataviewer.utilities;

import java.io.File;
import java.io.IOException;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.apache.commons.lang.StringUtils;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.slf4j.Logger;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;

import hydrograph.ui.common.schema.Field;
import hydrograph.ui.common.schema.Fields;
import hydrograph.ui.common.schema.Schema;
import hydrograph.ui.common.util.Constants;
import hydrograph.ui.logging.factory.LogFactory;

/**
 * The Class ViewDataSchemaHelper.
 * Used for schema file operations at watchers
 *  
 * @author  Bitwise
 *
 */
public class ViewDataSchemaHelper {

    private static final Logger logger = LogFactory.INSTANCE.getLogger(ViewDataSchemaHelper.class);
    public static ViewDataSchemaHelper INSTANCE = new ViewDataSchemaHelper();

    private ViewDataSchemaHelper() {
    }

    /**
     * This function will read schema file and return schema fields
     * @param schemaFilePath
     * @return Fields
     */
    public Fields getFieldsFromSchema(String schemaFilePath) {
        Fields fields = null;
        if (StringUtils.isNotBlank(schemaFilePath)) {
            String filePath = ((IPath) new Path(schemaFilePath)).removeFileExtension()
                    .addFileExtension(Constants.XML_EXTENSION_FOR_IPATH).toString();
            File file = new File(filePath);
            if (file.exists()) {
                try {
                    DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
                    builderFactory.setExpandEntityReferences(false);
                    builderFactory.setNamespaceAware(true);
                    builderFactory.setFeature(Constants.DISALLOW_DOCTYPE_DECLARATION, true);

                    DocumentBuilder documentBuilder = builderFactory.newDocumentBuilder();

                    Document document = documentBuilder.parse(file);
                    JAXBContext jaxbContext = JAXBContext.newInstance(Schema.class);
                    Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
                    Schema schema = (Schema) jaxbUnmarshaller.unmarshal(document);
                    fields = schema.getFields();
                    for (Field field : fields.getField()) {
                        logger.debug("Type:{}, Name:{}, Format:{}" + field.getType(), field.getName(),
                                field.getFormat());
                    }
                } catch (JAXBException | ParserConfigurationException | SAXException | IOException exception) {
                    logger.error("Invalid xml file: ", exception);
                }
            }
        }
        return fields;
    }
}