Coverage Report

Coverage Report - org.melati.poem.CachedQuery

Classes in this File

Line Coverage

Branch Coverage

Complexity

CachedQuery

87%

43/49

100%

22/22

2.778

 /*
  * $Source$
  * $Revision$
  *
  * Copyright (C) 2000 William Chesters
  *
  * Part of Melati (http://melati.org), a framework for the rapid
  * development of clean, maintainable web applications.
  *
  * Melati is free software; Permission is granted to copy, distribute
  * and/or modify this software under the terms either:
  *
  * a) the GNU General Public License as published by the Free Software
  *    Foundation; either version 2 of the License, or (at your option)
  *    any later version,
  *
  *    or
  *
  * b) any version of the Melati Software License, as published
  *    at http://melati.org
  *
  * You should have received a copy of the GNU General Public License and
  * the Melati Software License along with this program;
  * if not, write to the Free Software Foundation, Inc.,
  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
  * GNU General Public License and visit http://melati.org to obtain the
  * Melati Software License.
  *
  * Feel free to contact the Developers of Melati (http://melati.org),
  * if you would like to work out a different arrangement than the options
  * outlined here.  It is our intention to allow Melati to be used by as
  * wide an audience as possible.
  *
  * 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.
  *
  * Contact details for copyright holder:
  *
  *     William Chesters <williamc At paneris.org>
  *     http://paneris.org/~williamc
  *     Obrechtstraat 114, 2517VX Den Haag, The Netherlands
  */
 
 package org.melati.poem;
 
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.Vector;
 
 /**
  * Object to return the results of a query with caching.
  * <p>
  * Cached results will be returned unless the relevant tables
  * have been updated since the query was last executed, in which case 
  * the results will be recomputed. 
  * 
  */
 public abstract class CachedQuery<T> {
 
   protected PreparedStatementFactory statements = null;
 
   protected Vector<Integer> rows = null;
 
   private long tableSerial;
 
   protected Table<?> table;
 
   private String query;
 
   private Table<?> otherTables[];
 
   private long otherTablesSerial[];
 
   /**
    * Constructor.
    * 
    * @param table the table to select from 
    * @param query the SQL query string 
    * @param otherTables an array of other tables involved in the query
    */
   public CachedQuery(final Table<?> table,
                      final String query,
           final Table<?> otherTables[]) {
     this.table = table;
     this.query = query;
     this.otherTables = otherTables;
     if (otherTables != null)
       otherTablesSerial = new long[otherTables.length];
   }
 
   protected PreparedStatementFactory statements() {
     if (statements == null)
       statements = new PreparedStatementFactory(
                        table.getDatabase(),
                        query);
 
     return statements;
   }
 
   protected Integer extract(ResultSet rs) throws SQLException {
     return new Integer(rs.getInt(1));
   }
 
   protected void compute() {
     Vector<Integer> rowsLocal = this.rows;
     SessionToken token = PoemThread.sessionToken();
     if (rowsLocal == null || somethingHasChanged(token.transaction)) {
       rowsLocal = new Vector<Integer>();
       try {
         ResultSet rs = statements().resultSet(token);
         try {
           while (rs.next())
             rowsLocal.addElement(extract(rs));
         } finally {
           try {
             rs.close();
           } catch (Exception e) {
             // Report the real problem above
             e = null; // shut Checkstyle up!
           }
         }
       } catch (SQLException e) {
         throw new SQLSeriousPoemException(e);
       }
       this.rows = rowsLocal;
       updateSerials(token.transaction);
     }
   }
 
   private boolean somethingHasChanged(PoemTransaction transaction) {
     if (table.serial(transaction) != tableSerial)
       return true;
 
     if (otherTables != null) {
       for (int i = 0; i < otherTables.length; i++) {
         if (otherTables[i].serial(transaction) != otherTablesSerial[i])
           return true;
       }
     }
 
     return false;
   }
 
   private void updateSerials(PoemTransaction transaction) {
     tableSerial = table.serial(transaction);
     if (otherTables != null) {
       for (int i = 0; i < otherTables.length; i++) {
         otherTablesSerial[i] = otherTables[i].serial(transaction);
       }
     }
   }
 
   /**
    * @return the table property
    */
   public Table<?> getTable() {
     return table;
   }
 
   /**
    * Used in constructor of {@link CachedSelection}.
    * @param query the query to set
    */
   protected void setQuery(String query) {
     this.query = query;
   }
 
   /**
    * {@inheritDoc}
    * 
    * @see java.lang.Object#toString()
    */
   public String toString() {
     return getClass().getName() + " " + query;
   }
 }

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.sql.ResultSet;
49		import java.sql.SQLException;
50		import java.util.Vector;
51
52		/**
53		* Object to return the results of a query with caching.
54		* <p>
55		* Cached results will be returned unless the relevant tables
56		* have been updated since the query was last executed, in which case
57		* the results will be recomputed.
58		*
59		*/
60		public abstract class CachedQuery<T> {
61
62	306	protected PreparedStatementFactory statements = null;
63
64	306	protected Vector<Integer> rows = null;
65
66		private long tableSerial;
67
68		protected Table<?> table;
69
70		private String query;
71
72		private Table<?> otherTables[];
73
74		private long otherTablesSerial[];
75
76		/**
77		* Constructor.
78		*
79		* @param table the table to select from
80		* @param query the SQL query string
81		* @param otherTables an array of other tables involved in the query
82		*/
83		public CachedQuery(final Table<?> table,
84		final String query,
85	306	final Table<?> otherTables[]) {
86	306	this.table = table;
87	306	this.query = query;
88	306	this.otherTables = otherTables;
89	306	if (otherTables != null)
90	1	otherTablesSerial = new long[otherTables.length];
91	306	}
92
93		protected PreparedStatementFactory statements() {
94	44	if (statements == null)
95	27	statements = new PreparedStatementFactory(
96	27	table.getDatabase(),
97		query);
98
99	44	return statements;
100		}
101
102		protected Integer extract(ResultSet rs) throws SQLException {
103	166	return new Integer(rs.getInt(1));
104		}
105
106		protected void compute() {
107	75	Vector<Integer> rowsLocal = this.rows;
108	75	SessionToken token = PoemThread.sessionToken();
109	75	if (rowsLocal == null \|\| somethingHasChanged(token.transaction)) {
110	44	rowsLocal = new Vector<Integer>();
111		try {
112	44	ResultSet rs = statements().resultSet(token);
113		try {
114	210	while (rs.next())
115	166	rowsLocal.addElement(extract(rs));
116		} finally {
117	0	try {
118	44	rs.close();
119	0	} catch (Exception e) {
120		// Report the real problem above
121	0	e = null; // shut Checkstyle up!
122	44	}
123	0	}
124	0	} catch (SQLException e) {
125	0	throw new SQLSeriousPoemException(e);
126	44	}
127	44	this.rows = rowsLocal;
128	44	updateSerials(token.transaction);
129		}
130	75	}
131
132		private boolean somethingHasChanged(PoemTransaction transaction) {
133	48	if (table.serial(transaction) != tableSerial)
134	16	return true;
135
136	32	if (otherTables != null) {
137	11	for (int i = 0; i < otherTables.length; i++) {
138	8	if (otherTables[i].serial(transaction) != otherTablesSerial[i])
139	1	return true;
140		}
141		}
142
143	31	return false;
144		}
145
146		private void updateSerials(PoemTransaction transaction) {
147	44	tableSerial = table.serial(transaction);
148	44	if (otherTables != null) {
149	9	for (int i = 0; i < otherTables.length; i++) {
150	6	otherTablesSerial[i] = otherTables[i].serial(transaction);
151		}
152		}
153	44	}
154
155		/**
156		* @return the table property
157		*/
158		public Table<?> getTable() {
159	4	return table;
160		}
161
162		/**
163		* Used in constructor of {@link CachedSelection}.
164		* @param query the query to set
165		*/
166		protected void setQuery(String query) {
167	294	this.query = query;
168	294	}
169
170		/**
171		* {@inheritDoc}
172		*
173		* @see java.lang.Object#toString()
174		*/
175		public String toString() {
176	1	return getClass().getName() + " " + query;
177		}
178		}