001: /*
002: * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
003: *
004: * This file is part of Resin(R) Open Source
005: *
006: * Each copy or derived work must preserve the copyright notice and this
007: * notice unmodified.
008: *
009: * Resin Open Source is free software; you can redistribute it and/or modify
010: * it under the terms of the GNU General Public License as published by
011: * the Free Software Foundation; either version 2 of the License, or
012: * (at your option) any later version.
013: *
014: * Resin Open Source is distributed in the hope that it will be useful,
015: * but WITHOUT ANY WARRANTY; without even the implied warranty of
016: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
017: * of NON-INFRINGEMENT. See the GNU General Public License for more
018: * details.
019: *
020: * You should have received a copy of the GNU General Public License
021: * along with Resin Open Source; if not, write to the
022: * Free SoftwareFoundation, Inc.
023: * 59 Temple Place, Suite 330
024: * Boston, MA 02111-1307 USA
025: *
026: * @author Scott Ferguson
027: */
028:
029: package com.caucho.jslib;
030:
031: import com.caucho.util.Exit;
032: import com.caucho.util.ExitListener;
033:
034: import javax.naming.InitialContext;
035: import javax.sql.DataSource;
036: import java.sql.Connection;
037: import java.sql.PreparedStatement;
038: import java.sql.ResultSet;
039: import java.sql.SQLException;
040: import java.sql.Statement;
041:
042: /**
043: * Encapsulates a database connection for JavaScript.
044: *
045: * <code><pre>
046: * var conn = new Database("jdbc/test");
047: * var rs = conn.query("select NAME from HOUSES");
048: *
049: * while (rs.next())
050: * out.writeln(rs.get(1) + "<br/>");
051: *
052: * conn.close();
053: * </pre></code>
054: */
055: public class Database {
056: private DataSource dataSource;
057: private Connection conn;
058: private Statement stmt;
059: private ResultSet rs;
060:
061: /**
062: * Creates a new database looking up the DataSource in JNDI.
063: *
064: * @param name jndi name to the data source
065: */
066: public Database(String name) throws Exception {
067: InitialContext cxt = null;
068:
069: try {
070: cxt = new InitialContext();
071: } catch (Exception e) {
072: }
073:
074: try {
075: if (cxt != null)
076: dataSource = (DataSource) cxt.lookup(name);
077: } catch (Exception e) {
078: }
079:
080: try {
081: if (dataSource == null && cxt != null)
082: dataSource = (DataSource) cxt.lookup("java:comp/env/"
083: + name);
084: } catch (Exception e) {
085: }
086:
087: try {
088: if (dataSource != null && cxt != null)
089: dataSource = (DataSource) cxt
090: .lookup("java:comp/env/jdbc/" + name);
091: } catch (Exception e) {
092: }
093:
094: if (dataSource == null)
095: throw new SQLException("no data source: " + name);
096:
097: // Automatically reclaim the database when the script ends
098: Exit.addExit(exitHandler, this );
099: }
100:
101: /**
102: * Execute the sql as a query.
103: */
104: public ResultSet query(String sql) throws SQLException {
105: if (rs != null) {
106: ResultSet rs = this .rs;
107: this .rs = null;
108: rs.close();
109: }
110:
111: Statement stmt = getStatement();
112:
113: rs = stmt.executeQuery(sql);
114:
115: return rs;
116: }
117:
118: /**
119: * Execute the sql as a query.
120: */
121: public int update(String sql) throws SQLException {
122: if (rs != null) {
123: ResultSet rs = this .rs;
124: this .rs = null;
125: rs.close();
126: }
127:
128: Connection conn = dataSource.getConnection();
129:
130: try {
131: Statement stmt = conn.createStatement();
132:
133: int count = stmt.executeUpdate(sql);
134:
135: stmt.close();
136:
137: return count;
138: } finally {
139: conn.close();
140: }
141: }
142:
143: /**
144: * Returns the JDBC DataSource. Applications that
145: * need direct access to the data source.
146: */
147: public DataSource getDataSource() throws SQLException {
148: return dataSource;
149: }
150:
151: /**
152: * Returns the JDBC Connection for the database. Applications that need
153: * direct access to the Connection can use this.
154: */
155: public Connection getConnection() throws SQLException {
156: if (conn == null) {
157: conn = dataSource.getConnection();
158: }
159:
160: return conn;
161: }
162:
163: /**
164: * Commits the current connection.
165: */
166: public void commit() throws SQLException {
167: if (this .conn != null) {
168: Connection conn = this .conn;
169: this .conn = null;
170: this .stmt = null;
171: this .rs = null;
172: conn.close();
173: }
174: }
175:
176: /**
177: * Returns the JDBC Statement for the database. Applications that
178: * need direct access to the Java Statement can use this.
179: */
180: public Statement getStatement() throws SQLException {
181: if (stmt == null) {
182: Connection conn = getConnection();
183:
184: stmt = conn.createStatement();
185: }
186:
187: return stmt;
188: }
189:
190: /**
191: * Returns the JDBC Statement for the database. Applications that
192: * need direct access to the Java Statement can use this.
193: */
194: public PreparedStatement prepare(String sql) throws SQLException {
195: Connection conn = getConnection();
196:
197: return conn.prepareStatement(sql);
198: }
199:
200: /**
201: * Close the connection. Automatically closes the ResultSet, Statement
202: * and Connection.
203: */
204: public void close() throws SQLException {
205: try {
206: if (rs != null) {
207: ResultSet rs = this .rs;
208: this .rs = null;
209: rs.close();
210: }
211:
212: if (stmt != null) {
213: Statement stmt = this .stmt;
214: this .stmt = null;
215: stmt.close();
216: }
217: } finally {
218: this .stmt = null;
219: this .rs = null;
220: if (conn != null) {
221: Connection conn = this .conn;
222: this .conn = null;
223: conn.close();
224: }
225: }
226: }
227:
228: /**
229: * Listens for the exit event. When Database is used in JavaScript,
230: * the database will be automatically closed on exit.
231: */
232: private static ExitListener exitHandler = new ExitListener() {
233: public void handleExit(Object o) {
234: Database db = (Database) o;
235:
236: try {
237: db.close();
238: } catch (SQLException e) {
239: }
240: }
241: };
242: }
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