com.livinglogic.dbutils.ResultSetMapIterator.java Source code

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Here is the source code for com.livinglogic.dbutils.ResultSetMapIterator.java

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/*
** Copyright 2013-2014 by LivingLogic AG, Bayreuth/Germany
** All Rights Reserved
** See LICENSE for the license
*/

package com.livinglogic.dbutils;

import static java.sql.Types.DATE;
import static java.sql.Types.TIMESTAMP;

import java.math.BigInteger;
import java.math.BigDecimal;
import java.sql.Clob;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.apache.commons.collections.map.CaseInsensitiveMap;

import com.livinglogic.ul4.Utils;

public class ResultSetMapIterator implements Iterator<Map<String, Object>> {
    private ResultSet resultSet;
    private ResultSetMetaData metaData;
    private int numberOfColumns;
    Map<String, Object> nextRecord;

    public ResultSetMapIterator(ResultSet resultSet) {
        this.resultSet = resultSet;
        try {
            metaData = resultSet.getMetaData();
            numberOfColumns = metaData.getColumnCount();
        } catch (SQLException ex) {
            throw new RuntimeException(ex);
        }
        nextRecord = null;
        fetch();
    }

    public boolean hasNext() {
        return nextRecord != null;
    }

    public Map<String, Object> next() {
        Map<String, Object> result = nextRecord;
        fetch();
        return result;
    }

    public void remove() {
        throw new UnsupportedOperationException();
    }

    private void fetch() {
        try {
            if (resultSet.next()) {
                Map<String, Object> record = new CaseInsensitiveMap();

                for (int i = 1; i <= numberOfColumns; ++i) {
                    String key = metaData.getColumnLabel(i);
                    int type = metaData.getColumnType(i);
                    Object value;
                    if (type == DATE)
                        value = resultSet.getDate(i);
                    else if (type == TIMESTAMP
                            // Don't use the constants from oracle.jdbc.OracleTypes, so that we don't require ojdbc.jar
                            || type == -102 // oracle.jdbc.OracleTypes.TIMESTAMPLTZ
                            || type == -100 // oracle.jdbc.OracleTypes.TIMESTAMPNS
                            || type == -101) // oracle.jdbc.OracleTypes.TIMESTAMPTZ
                        value = resultSet.getTimestamp(i);
                    else {
                        value = resultSet.getObject(i);
                        if (value instanceof Clob) {
                            String stringValue = ((Clob) value).getSubString(1L, (int) ((Clob) value).length());
                            try {
                                ((Clob) value).free();
                            } catch (SQLException ex) {
                            }
                            value = stringValue;
                        } else if (value instanceof BigDecimal)
                            value = Utils.narrowBigDecimal((BigDecimal) value);
                        else if (value instanceof BigInteger)
                            value = Utils.narrowBigInteger((BigInteger) value);
                    }
                    record.put(key, value);
                }
                nextRecord = record;
            } else {
                nextRecord = null;
                resultSet.close();
            }
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }
}