| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| ResultSetEnumeration |
|
| 4.833333333333333;4.833 |
| 1 | /* | |
| 2 | * $Source$ | |
| 3 | * $Revision$ | |
| 4 | * | |
| 5 | * Copyright (C) 2000 William Chesters | |
| 6 | * | |
| 7 | * Part of Melati (http://melati.org), a framework for the rapid | |
| 8 | * development of clean, maintainable web applications. | |
| 9 | * | |
| 10 | * Melati is free software; Permission is granted to copy, distribute | |
| 11 | * and/or modify this software under the terms either: | |
| 12 | * | |
| 13 | * a) the GNU General Public License as published by the Free Software | |
| 14 | * Foundation; either version 2 of the License, or (at your option) | |
| 15 | * any later version, | |
| 16 | * | |
| 17 | * or | |
| 18 | * | |
| 19 | * b) any version of the Melati Software License, as published | |
| 20 | * at http://melati.org | |
| 21 | * | |
| 22 | * You should have received a copy of the GNU General Public License and | |
| 23 | * the Melati Software License along with this program; | |
| 24 | * if not, write to the Free Software Foundation, Inc., | |
| 25 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the | |
| 26 | * GNU General Public License and visit http://melati.org to obtain the | |
| 27 | * Melati Software License. | |
| 28 | * | |
| 29 | * Feel free to contact the Developers of Melati (http://melati.org), | |
| 30 | * if you would like to work out a different arrangement than the options | |
| 31 | * outlined here. It is our intention to allow Melati to be used by as | |
| 32 | * wide an audience as possible. | |
| 33 | * | |
| 34 | * This program is distributed in the hope that it will be useful, | |
| 35 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 36 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 37 | * GNU General Public License for more details. | |
| 38 | * | |
| 39 | * Contact details for copyright holder: | |
| 40 | * | |
| 41 | * William Chesters <williamc At paneris.org> | |
| 42 | * http://paneris.org/~williamc | |
| 43 | * Obrechtstraat 114, 2517VX Den Haag, The Netherlands | |
| 44 | */ | |
| 45 | ||
| 46 | package org.melati.poem; | |
| 47 | ||
| 48 | import java.util.NoSuchElementException; | |
| 49 | import java.sql.ResultSet; | |
| 50 | import java.sql.SQLException; | |
| 51 | import org.melati.poem.util.SkipEnumeration; | |
| 52 | ||
| 53 | /** | |
| 54 | * An <code>Enumeration</code> created by filtering a | |
| 55 | * <code>ResultSet</code> according to an abstract | |
| 56 | * function applied to each element of the <code>ResultSet</code>. | |
| 57 | * <p> | |
| 58 | * Implementations must provide {@link #mapped(ResultSet)}. | |
| 59 | */ | |
| 60 | public abstract class ResultSetEnumeration<T> implements SkipEnumeration<T> { | |
| 61 | private final ResultSet resultSet; | |
| 62 | 2807 | private int more = -1; |
| 63 | ||
| 64 | /** | |
| 65 | * Constructor. | |
| 66 | * @param resultSet the ResultSet property | |
| 67 | */ | |
| 68 | 2807 | public ResultSetEnumeration(ResultSet resultSet) { |
| 69 | 2807 | this.resultSet = resultSet; |
| 70 | 2807 | } |
| 71 | ||
| 72 | private int resultSetNext() throws SQLException { | |
| 73 | boolean hasNext; | |
| 74 | try { | |
| 75 | 4049 | hasNext = resultSet.next(); |
| 76 | 0 | } catch (SQLException e) { |
| 77 | // Assumed to be closed resultset | |
| 78 | 0 | return 0; |
| 79 | 4049 | } |
| 80 | 4049 | if (hasNext) |
| 81 | 1248 | return 1; |
| 82 | else { | |
| 83 | try { | |
| 84 | 2801 | resultSet.close(); |
| 85 | 0 | } catch (SQLException e) { |
| 86 | 0 | throw new SQLSeriousPoemException(e); |
| 87 | 2801 | } |
| 88 | 2801 | return 0; |
| 89 | } | |
| 90 | } | |
| 91 | ||
| 92 | /** | |
| 93 | * {@inheritDoc} | |
| 94 | * @see java.util.Enumeration#hasMoreElements() | |
| 95 | */ | |
| 96 | public synchronized boolean hasMoreElements() { | |
| 97 | try { | |
| 98 | 3280 | if (more == -1) |
| 99 | 2794 | more = resultSetNext(); |
| 100 | 3280 | return more == 1; |
| 101 | 0 | } catch (SQLException e) { |
| 102 | 0 | throw new SQLSeriousPoemException(e); |
| 103 | } | |
| 104 | } | |
| 105 | ||
| 106 | protected abstract Object mapped(ResultSet resultSetP) | |
| 107 | throws SQLException, NoSuchRowPoemException; | |
| 108 | ||
| 109 | /** | |
| 110 | * Return the next element. | |
| 111 | * <p> | |
| 112 | * NOTE A {@link RowDisappearedPoemException} might be thrown | |
| 113 | * but does not prevent subsequent use of the object. | |
| 114 | * @see java.util.Enumeration#nextElement() | |
| 115 | */ | |
| 116 | @SuppressWarnings("unchecked") | |
| 117 | public synchronized T nextElement() throws NoSuchElementException { | |
| 118 | try { | |
| 119 | 1242 | if (more == -1) |
| 120 | 11 | more = resultSetNext(); |
| 121 | ||
| 122 | 1242 | if (more == 0) |
| 123 | 2 | throw new NoSuchElementException(); |
| 124 | ||
| 125 | try { | |
| 126 | 1240 | return (T) mapped(resultSet); |
| 127 | } | |
| 128 | finally { | |
| 129 | 1238 | more = resultSetNext(); |
| 130 | } | |
| 131 | 0 | } catch (SQLException e) { |
| 132 | 0 | throw new SQLSeriousPoemException(e); |
| 133 | 0 | } catch (NoSuchRowPoemException e) { |
| 134 | 0 | throw new RowDisappearedPoemException(e); |
| 135 | } | |
| 136 | } | |
| 137 | ||
| 138 | /** | |
| 139 | * {@inheritDoc} | |
| 140 | * @see org.melati.poem.util.SkipEnumeration#skip() | |
| 141 | */ | |
| 142 | public synchronized void skip() throws NoSuchElementException { | |
| 143 | try { | |
| 144 | 3 | if (more == -1) |
| 145 | 2 | more = resultSetNext(); |
| 146 | 3 | if (more == 0) |
| 147 | 1 | throw new NoSuchElementException(); |
| 148 | 2 | more = resultSetNext(); |
| 149 | 0 | } catch (SQLException e) { |
| 150 | 0 | throw new SQLSeriousPoemException(e); |
| 151 | 2 | } |
| 152 | 2 | } |
| 153 | } |