org.eclipse.birt.data.oda.mongodb.impl.MDbResultSet.java Source code

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/*
 *************************************************************************
 * Copyright (c) 2013 Actuate Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *  Actuate Corporation - initial API and implementation
 *  
 *************************************************************************
 */

package org.eclipse.birt.data.oda.mongodb.impl;

import java.math.BigDecimal;
import java.sql.Date;
import java.sql.Time;
import java.sql.Timestamp;
import java.util.Iterator;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.xml.bind.DatatypeConverter;

import org.apache.commons.codec.binary.Base64;
import org.bson.Document;
import org.bson.types.BSONTimestamp;
import org.eclipse.birt.data.oda.mongodb.internal.impl.DriverUtil;
import org.eclipse.birt.data.oda.mongodb.internal.impl.QueryProperties;
import org.eclipse.birt.data.oda.mongodb.internal.impl.ResultDataHandler;
import org.eclipse.birt.data.oda.mongodb.internal.impl.MDbMetaData.FieldMetaData;
import org.eclipse.birt.data.oda.mongodb.nls.Messages;
import org.eclipse.datatools.connectivity.oda.IBlob;
import org.eclipse.datatools.connectivity.oda.IClob;
import org.eclipse.datatools.connectivity.oda.IResultSet;
import org.eclipse.datatools.connectivity.oda.IResultSetMetaData;
import org.eclipse.datatools.connectivity.oda.OdaException;
import org.eclipse.datatools.connectivity.oda.impl.Blob;

import com.mongodb.BasicDBList;
import com.mongodb.DBCursor;

/**
 * Implementation class of IResultSet for the MongoDB ODA runtime driver.
 */
@SuppressWarnings("deprecation")
public class MDbResultSet implements IResultSet {
    private Iterator<Document> m_resultsIterator;
    private DBCursor m_mongoCursor;
    private MDbResultSetMetaData m_metadata;
    private QueryProperties m_queryProps;

    private Document m_currentRow;
    private int m_currentRowId = 0; // 1-based index
    private int m_maxRows = 0; // no limit by default
    private boolean m_wasNull = true;
    private ResultDataHandler m_dataHandler;

    private static Logger sm_logger = DriverUtil.getLogger();

    public MDbResultSet(Iterator<Document> resultsIterator, MDbResultSetMetaData rsmd, QueryProperties queryProps) {
        if (resultsIterator == null || rsmd == null)
            throw new IllegalArgumentException("null DBCursor"); //$NON-NLS-1$

        m_resultsIterator = resultsIterator;
        //if( resultsIterator instanceof DBCursor )
        //    m_mongoCursor = (DBCursor)resultsIterator;
        m_metadata = rsmd;
        m_queryProps = queryProps != null ? queryProps : QueryProperties.defaultValues();
        if (projectsFlattenedRows())
            m_dataHandler = new ResultDataHandler(m_metadata);
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getMetaData()
     */
    public IResultSetMetaData getMetaData() throws OdaException {
        return m_metadata;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#setMaxRows(int)
     */
    public void setMaxRows(int max) throws OdaException {
        m_maxRows = max;
        if (m_maxRows > 0 && m_mongoCursor != null)
            m_mongoCursor.limit(m_maxRows);
    }

    /**
     * Returns the maximum number of rows that can be fetched from this result set.
     * @return the maximum number of rows to fetch.
     */
    protected int getMaxRows() {
        return m_maxRows >= 0 ? m_maxRows : 0; // negative value is ignored
    }

    private boolean hasNoMaxLimit() {
        return m_maxRows <= 0;
    }

    private boolean projectsFlattenedRows() {
        return m_queryProps.isAutoFlattening();
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#next()
     */
    public boolean next() throws OdaException {
        // handle automatic flattening of embedded objects - default is false
        if (projectsFlattenedRows()) {
            if (m_dataHandler != null && m_dataHandler.next())
                return true;
        }

        // get next row from the iterator
        m_currentRow = null; // reset
        if (m_resultsIterator == null || !m_resultsIterator.hasNext())
            return false;

        // has next row; check the maximum rows limit
        if (hasNoMaxLimit() || m_currentRowId < getMaxRows()) {
            m_currentRow = m_resultsIterator.next();
            m_currentRowId++;
            return true;
        }

        return false;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#close()
     */
    public void close() throws OdaException {
        m_currentRow = null;
        m_currentRowId = 0; // reset row counter
        m_resultsIterator = null;
        if (m_mongoCursor != null) {
            m_mongoCursor.close();
            m_mongoCursor = null;
        }
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getRow()
     */
    public int getRow() throws OdaException {
        return m_currentRowId;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getString(int)
     */
    public String getString(int index) throws OdaException {
        return getString(findFieldName(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getString(java.lang.String)
     */
    public String getString(String columnName) throws OdaException {
        Object columnValue = getFieldValue(columnName);
        if (columnValue instanceof String)
            return (String) columnValue;

        if (columnValue instanceof List && !(columnValue instanceof BasicDBList)) {
            // convert generic List to JSON-formattable list
            List<?> fromList = (List<?>) columnValue;
            if (!fromList.isEmpty()) {
                BasicDBList fieldValuesList = new BasicDBList();
                for (int index = 0; index < fromList.size(); index++) {
                    fieldValuesList.put(index, fromList.get(index));
                }
                fieldValuesList.markAsPartialObject();
                return fieldValuesList.toString(); // return JSON expr format
            }
        }

        if (columnValue instanceof byte[])
            return convertToString((byte[]) columnValue);

        return columnValue != null ? columnValue.toString() : null;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getInt(int)
     */
    public int getInt(int index) throws OdaException {
        return getInt(findFieldName(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getInt(java.lang.String)
     */
    public int getInt(String columnName) throws OdaException {
        Object columnValue = getFieldValue(columnName);
        columnValue = tryConvertToDataType(columnValue, Integer.class);

        if (columnValue instanceof List)
            columnValue = getFirstFieldValue((List<?>) columnValue, Integer.class, columnName);
        if (columnValue instanceof Integer)
            return (Integer) columnValue;

        // not convertible
        if (columnValue != null) {
            String errMsg = Messages.bind(Messages.mDbResultSet_cannotConvertFieldData,
                    new Object[] { columnName, columnValue, columnValue.getClass().getSimpleName(), "integer" }); //$NON-NLS-1$
            getLogger().severe(errMsg);
            throw new OdaException(errMsg);
        }

        // null value
        return 0;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getDouble(int)
     */
    public double getDouble(int index) throws OdaException {
        return getDouble(findFieldName(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getDouble(java.lang.String)
     */
    public double getDouble(String columnName) throws OdaException {
        Object columnValue = getFieldValue(columnName);
        columnValue = tryConvertToDataType(columnValue, Double.class);

        if (columnValue instanceof List)
            columnValue = getFirstFieldValue((List<?>) columnValue, Double.class, columnName);
        if (columnValue instanceof Double)
            return (Double) columnValue;

        // not convertible
        if (columnValue != null) {
            String errMsg = Messages.bind(Messages.mDbResultSet_cannotConvertFieldData,
                    new Object[] { columnName, columnValue, columnValue.getClass().getSimpleName(), "double" }); //$NON-NLS-1$
            getLogger().severe(errMsg);
            throw new OdaException(errMsg);
        }

        // null value
        return 0d;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBigDecimal(int)
     */
    public BigDecimal getBigDecimal(int index) throws OdaException {
        return getBigDecimal(findFieldName(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBigDecimal(java.lang.String)
     */
    public BigDecimal getBigDecimal(String columnName) throws OdaException {
        Object columnValue = getFieldValue(columnName);
        columnValue = tryConvertToDataType(columnValue, BigDecimal.class);
        if (columnValue instanceof BigDecimal)
            return (BigDecimal) columnValue;

        if (columnValue instanceof List)
            return (BigDecimal) getFirstFieldValue((List<?>) columnValue, BigDecimal.class, columnName);

        // not convertible
        if (columnValue != null) {
            String errMsg = Messages.bind(Messages.mDbResultSet_cannotConvertFieldData,
                    new Object[] { columnName, columnValue, columnValue.getClass().getSimpleName(), "BigDecimal" }); //$NON-NLS-1$
            getLogger().severe(errMsg);
            throw new OdaException(errMsg);
        }

        return null;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getDate(int)
     */
    public Date getDate(int index) throws OdaException {
        return getDate(findFieldName(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getDate(java.lang.String)
     */
    public Date getDate(String columnName) throws OdaException {
        Object columnValue = getFieldValue(columnName);
        columnValue = tryConvertToDataType(columnValue, Date.class);
        if (columnValue instanceof Date)
            return (Date) columnValue;

        if (columnValue instanceof List)
            return (Date) getFirstFieldValue((List<?>) columnValue, Date.class, columnName);

        // not convertible
        if (columnValue != null) {
            String errMsg = Messages.bind(Messages.mDbResultSet_cannotConvertFieldData,
                    new Object[] { columnName, columnValue, columnValue.getClass().getSimpleName(), "Date" }); //$NON-NLS-1$
            getLogger().severe(errMsg);
            throw new OdaException(errMsg);
        }

        return null;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getTime(int)
     */
    public Time getTime(int index) throws OdaException {
        return getTime(findFieldName(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getTime(java.lang.String)
     */
    public Time getTime(String columnName) throws OdaException {
        Date dateValue = getDate(columnName);
        if (dateValue == null)
            return null;
        return new Time(dateValue.getTime());
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getTimestamp(int)
     */
    public Timestamp getTimestamp(int index) throws OdaException {
        return getTimestamp(findFieldName(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getTimestamp(java.lang.String)
     */
    public Timestamp getTimestamp(String columnName) throws OdaException {
        Object columnValue = getFieldValue(columnName);
        columnValue = tryConvertToDataType(columnValue, Timestamp.class);

        if (columnValue instanceof List)
            columnValue = getFirstFieldValue((List<?>) columnValue, Timestamp.class, columnName);
        if (columnValue instanceof Timestamp)
            return (Timestamp) columnValue;

        // not convertible
        if (columnValue != null) {
            String errMsg = Messages.bind(Messages.mDbResultSet_cannotConvertFieldData,
                    new Object[] { columnName, columnValue, columnValue.getClass().getSimpleName(), "Timestamp" }); //$NON-NLS-1$
            getLogger().severe(errMsg);
            throw new OdaException(errMsg);
        }

        return null;
    }

    /* 
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBlob(int)
     */
    public IBlob getBlob(int index) throws OdaException {
        return getBlob(findFieldName(index));
    }

    /* 
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBlob(java.lang.String)
     */
    public IBlob getBlob(String columnName) throws OdaException {
        Object columnValue = getFieldValue(columnName);
        columnValue = tryConvertToDataType(columnValue, byte[].class);

        if (columnValue instanceof List)
            columnValue = getFirstFieldValue((List<?>) columnValue, byte[].class, columnName);
        if (columnValue instanceof byte[])
            return new Blob((byte[]) columnValue);

        // not convertible
        if (columnValue != null) {
            String errMsg = Messages.bind(Messages.mDbResultSet_cannotConvertFieldData,
                    new Object[] { columnName, columnValue, columnValue.getClass().getSimpleName(), "Blob" }); //$NON-NLS-1$
            getLogger().severe(errMsg);
            throw new OdaException(errMsg);
        }

        return null;
    }

    /* 
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getClob(int)
     */
    public IClob getClob(int index) throws OdaException {
        throw MDbQuery.sm_unSupportedOpEx;
    }

    /* 
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getClob(java.lang.String)
     */
    public IClob getClob(String columnName) throws OdaException {
        throw MDbQuery.sm_unSupportedOpEx;
    }

    /* (non-Javadoc)
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBoolean(int)
     */
    public boolean getBoolean(int index) throws OdaException {
        return getBoolean(findFieldName(index));
    }

    /* (non-Javadoc)
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBoolean(java.lang.String)
     */
    public boolean getBoolean(String columnName) throws OdaException {
        Object columnValue = getFieldValue(columnName);
        columnValue = tryConvertToDataType(columnValue, Boolean.class);

        if (columnValue instanceof List)
            columnValue = getFirstFieldValue((List<?>) columnValue, Boolean.class, columnName);
        if (columnValue instanceof Boolean)
            return (Boolean) columnValue;

        // not convertible
        if (columnValue != null) {
            String errMsg = Messages.bind(Messages.mDbResultSet_cannotConvertFieldData,
                    new Object[] { columnName, columnValue, columnValue.getClass().getSimpleName(), "boolean" }); //$NON-NLS-1$
            getLogger().severe(errMsg);
            throw new OdaException(errMsg);
        }

        // null value
        return false;
    }

    /* (non-Javadoc)
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getObject(int)
     */
    public Object getObject(int index) throws OdaException {
        return getObject(findFieldName(index));
    }

    /* (non-Javadoc)
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getObject(java.lang.String)
     */
    public Object getObject(String columnName) throws OdaException {
        return getFieldValue(columnName);
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#wasNull()
     */
    public boolean wasNull() throws OdaException {
        return m_wasNull;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#findColumn(java.lang.String)
     */
    public int findColumn(String columnName) throws OdaException {
        return m_metadata.getColumnNumber(columnName);
    }

    private String findFieldName(int columnNumber) throws OdaException {
        return getMetaData().getColumnName(columnNumber);
    }

    private Object getFieldValue(String columnName) throws OdaException {
        Object fieldValue = doGetFieldValue(columnName);
        m_wasNull = (fieldValue == null);
        return fieldValue;
    }

    private Object doGetFieldValue(String columnName) throws OdaException {
        if (!projectsFlattenedRows()) {
            FieldMetaData fieldMD = m_metadata.getColumnMetaData(columnName);
            return ResultDataHandler.fetchFieldValues(columnName, fieldMD, m_currentRow);
        }

        // flatten array of nested documents' field values, if exists, and projects into multiple result rows
        return m_dataHandler.getFieldValue(columnName, m_currentRow);
    }

    /* Get specified type of value from the first element in an array;
     * handles nested arrays.
     * Returns a null value if not able to return value in the specified valueDataType.
     */
    private Object getFirstFieldValue(List<?> valuesList, Class<?> valueDataType, String logColumnName)
            throws OdaException {
        Object value = getFirstElementFromList(valuesList, logColumnName);
        value = tryConvertToDataType(value, valueDataType);
        if (valueDataType.isInstance(value))
            return value;
        if (value instanceof List) // nested array
            return getFirstFieldValue((List<?>) value, valueDataType, logColumnName);

        // not convertible
        if (value != null && getLogger().isLoggable(Level.FINE))
            getLogger().fine(Messages.bind(
                    "Unable to get the '{0}' field's first array value ({1}) in {2} data type as a {3} value.", //$NON-NLS-1$
                    new Object[] { logColumnName, value, value.getClass().getSimpleName(),
                            valueDataType.getSimpleName() }));

        m_wasNull = true;
        return null;
    }

    private static Object getFirstElementFromList(List<?> valuesList, String columnName) {
        if (valuesList.size() == 0)
            return null;
        Object firstValue = null;
        if (valuesList instanceof BasicDBList)
            firstValue = ((BasicDBList) valuesList).get(String.valueOf(0));
        else
            firstValue = valuesList.get(0);

        // log that only first value in array is returned
        logFetchedFirstElementFromArray(columnName, valuesList.size());
        return firstValue;
    }

    private static Object tryConvertToDataType(Object value, Class<?> toDataType) throws OdaException {
        if (value == null || toDataType.isInstance(value)) // already in specified data type
            return value;

        try {
            if (value instanceof String) {
                String stringValue = (String) value;
                if (toDataType == Integer.class)
                    return Integer.valueOf(stringValue);
                if (toDataType == Double.class)
                    return Double.valueOf(stringValue);
                if (toDataType == BigDecimal.class)
                    return new BigDecimal(stringValue);
                if (toDataType == Boolean.class)
                    return Boolean.valueOf(stringValue);
                if (toDataType == Date.class)
                    return Date.valueOf(stringValue);
                if (toDataType == Timestamp.class)
                    return Timestamp.valueOf(stringValue);
                if (toDataType == byte[].class)
                    return tryConvertToBytes(stringValue);
            }

            if (value instanceof java.util.Date) // the object type returned by MongoDB for a Date field
            {
                long msTime = ((java.util.Date) value).getTime();
                if (toDataType == Date.class)
                    return new Date(msTime);
                if (toDataType == Timestamp.class)
                    return new Timestamp(msTime);
            }

            if (value instanceof BSONTimestamp) {
                long msTime = ((BSONTimestamp) value).getTime() * 1000L;
                if (toDataType == Date.class)
                    return new Date(msTime);
                if (toDataType == Timestamp.class)
                    return new Timestamp(msTime);
            }

            if (toDataType == Integer.class)
                return tryConvertToInteger(value);
            if (toDataType == Double.class)
                return tryConvertToDouble(value);
            if (toDataType == Boolean.class)
                return tryConvertToBoolean(value);
        } catch (Exception ex) {
            String errMsg = Messages.bind(Messages.mDbResultSet_cannotConvertFieldData, new Object[] {
                    DriverUtil.EMPTY_STRING, value, value.getClass().getSimpleName(), toDataType.getSimpleName() });
            getLogger().severe(errMsg);

            OdaException odaEx = new OdaException(errMsg);
            odaEx.initCause(ex);
            throw odaEx;
        }

        // non-handled data type conversion; return value as is
        return value;
    }

    private static Object tryConvertToInteger(Object value) {
        if (value instanceof Number)
            return Integer.valueOf(((Number) value).intValue());
        if (value instanceof Boolean)
            return ((Boolean) value) ? Integer.valueOf(1) : Integer.valueOf(0);
        return value; // not able to convert; return value as is
    }

    private static Object tryConvertToDouble(Object value) {
        if (value instanceof Number)
            return Double.valueOf(((Number) value).doubleValue());
        if (value instanceof Boolean)
            return ((Boolean) value) ? Double.valueOf(1d) : Double.valueOf(0d);
        return value; // not able to convert; return value as is
    }

    private static Object tryConvertToBoolean(Object value) {
        if (value instanceof Number)
            return ((Number) value).doubleValue() != 0 ? Boolean.TRUE : Boolean.FALSE;
        return value; // not able to convert; return value as is
    }

    private static Object tryConvertToBytes(String stringValue) {
        try {
            return DatatypeConverter.parseBase64Binary(stringValue);
        } catch (Exception ex) {
            // DatatypeConverter could be un-initialized,
            // log and continue; note that Base64Codec#decode might be unavailable in some versions
            if (getLogger().isLoggable(Level.FINE))
                getLogger().fine(Messages.bind(
                        "Unable to convert the String field value ({0}) to a bytes[] value.\n Cause: {1}", //$NON-NLS-1$
                        stringValue, ex.getMessage()));
        }
        return stringValue; // not able to convert; return value as is
    }

    private static String convertToString(byte[] value) {
        try {
            return DatatypeConverter.printBase64Binary(value);
        } catch (Exception ex) {
            // DatatypeConverter could be un-initialized; retry with Base64Codec
            return (new String(Base64.encodeBase64(value)));
        }
    }

    private static void logFetchedFirstElementFromArray(String columnName, int arraySize) {
        // log that only first value in set is returned
        if (arraySize > 1 && getLogger().isLoggable(Level.FINER))
            getLogger().finer(Messages.bind("Fetching only the first value out of {0} for the field {1}.", //$NON-NLS-1$
                    Integer.valueOf(arraySize), columnName));
    }

    private static Logger getLogger() {
        return sm_logger;
    }

}