Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2020 gvSIG Association.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 3

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.fmap.dal.store.jdbc2.spi.operations;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.List;

import org.apache.commons.lang3.StringUtils;

import org.gvsig.expressionevaluator.ExpressionBuilder;

import org.gvsig.fmap.dal.SQLBuilder;

import static org.gvsig.fmap.dal.SQLBuilder.PROP_FEATURE_TYPE;

import static org.gvsig.fmap.dal.SQLBuilder.PROP_JDBCHELPER;

import static org.gvsig.fmap.dal.SQLBuilder.PROP_QUERY;

import static org.gvsig.fmap.dal.SQLBuilder.PROP_SYMBOLTABLE;

import static org.gvsig.fmap.dal.SQLBuilder.PROP_TABLE;

import static org.gvsig.fmap.dal.SQLBuilder.PROP_TABLENAME;

import org.gvsig.fmap.dal.exception.DataException;

import org.gvsig.fmap.dal.feature.FeatureAttributeDescriptor;

import org.gvsig.fmap.dal.feature.FeatureType;

import org.gvsig.fmap.dal.feature.spi.FeatureProvider;

import org.gvsig.fmap.dal.feature.spi.FeatureReferenceProviderServices;

import org.gvsig.fmap.dal.store.jdbc.exception.JDBCSQLException;

import org.gvsig.fmap.dal.store.jdbc2.JDBCConnection;

import org.gvsig.fmap.dal.store.jdbc2.JDBCHelper;

import org.gvsig.fmap.dal.store.jdbc2.JDBCUtils;

import org.gvsig.fmap.dal.store.jdbc2.OperationsFactory.TableReference;

import org.gvsig.fmap.dal.store.jdbc2.spi.JDBCSQLBuilderBase;

import static org.gvsig.fmap.dal.store.jdbc2.spi.JDBCSQLBuilderBase.PROP_FEATURE_TYPE;

import static org.gvsig.fmap.dal.store.jdbc2.spi.JDBCSQLBuilderBase.PROP_TABLE;

import static org.gvsig.fmap.dal.store.jdbc2.spi.operations.ResultSetForSetProviderOperation.process1_SimpleFields;

import static org.gvsig.fmap.dal.store.jdbc2.spi.operations.ResultSetForSetProviderOperation.process2_ComputedFields;

import org.gvsig.fmap.geom.DataTypes;

public class FetchFeatureProviderByReferenceOperation extends AbstractConnectionOperation {

    private final FeatureType featureType;

    private final FeatureReferenceProviderServices reference;

    private final TableReference table;

    public FetchFeatureProviderByReferenceOperation(

            JDBCHelper helper,

            FeatureReferenceProviderServices reference,

            FeatureType featureType,

            TableReference table

        ) {

        super(helper);

        this.reference = reference;

        this.table = table;

        this.featureType = featureType;

    }

    @Override

    public final Object perform(JDBCConnection conn) throws DataException {

        FeatureProvider feature = fetchFeatureProviderByReference(conn);

        return feature;

    }

    public String getSQL() {

        List<FeatureAttributeDescriptor> columns = new ArrayList<>();        

        JDBCSQLBuilderBase sqlbuilder = this.createSQLBuilder();

        String sql = this.getSQL(sqlbuilder,columns);

        return sql;

    }

    public String getSQL(JDBCSQLBuilderBase sqlbuilder, List<FeatureAttributeDescriptor> columns) {

        List<String> primaryKeys = new ArrayList<>();

        for (String primaryKey : reference.getKeyNames()) {

            primaryKeys.add(primaryKey);

        }

        ExpressionBuilder expbuilder = sqlbuilder.expression();

        expbuilder.setProperty(PROP_FEATURE_TYPE, this.featureType);

        expbuilder.setProperty(PROP_TABLE, table);

        expbuilder.setProperty(PROP_TABLENAME, table.getTable());

        expbuilder.setProperty(PROP_JDBCHELPER, this.helper);

        SQLBuilder.SelectBuilder select = sqlbuilder.select();

        select.from().table()

                .database(this.table.getDatabase())

                .schema(this.table.getSchema())

                .name(this.table.getTable());

        process1_SimpleFields(helper, this.featureType, null, sqlbuilder, select, columns, primaryKeys, null);

        process2_ComputedFields(helper, this.featureType, null, sqlbuilder, select, null);

        for (String name : primaryKeys )  {

            if( !select.has_column(name) ) {

                select.column().name(name);

                columns.add(featureType.getAttributeDescriptor(name));

            }

            Object value = reference.getKeyValue(name);

            if( value == null ) {

                select.where().and(

                    expbuilder.is_null(select.column(name))

                );                

            } else {

                select.where().and(

                    expbuilder.eq(

                        select.column(name), 

                        expbuilder.parameter(name).value(value)

                    )

                );              

            }

        }

        select.limit(1);

        sqlbuilder.setProperties(

                null,

                PROP_FEATURE_TYPE, this.featureType,

                PROP_TABLE, table,

                PROP_JDBCHELPER, this.helper

        );

        this.helper.expandCalculedColumns(sqlbuilder);

        this.helper.processSpecialFunctions(sqlbuilder, this.featureType, null, null);

        String sql = StringUtils.trim(sqlbuilder.toString());

        return sql;

    }

    public FeatureProvider fetchFeatureProviderByReference(

            JDBCConnection conn

        ) throws DataException {

        List<FeatureAttributeDescriptor> columns = new ArrayList<>();        

        JDBCSQLBuilderBase sqlbuilder = this.createSQLBuilder();

        String sql = this.getSQL(sqlbuilder,columns);

        PreparedStatement st = null;

        ResultSet rs = null;

        try {

            st = conn.prepareStatement(sql);

            sqlbuilder.setParameters(st);

            rs = JDBCUtils.executeQuery(st, sql);

            if (!rs.next()) {

                return null;

            }

            FeatureProvider data = this.helper.createFeature(featureType);

            this.helper.fetchFeature(data, rs, columns.toArray(new FeatureAttributeDescriptor[columns.size()]), null); 

            return data;

        } catch (SQLException ex) {

            throw new JDBCSQLException(ex,sql);

        } finally {

            JDBCUtils.closeQuietly(st);

            JDBCUtils.closeQuietly(rs);

        }        

    }

}