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1 /** |
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2 * SQL-DK |
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3 * Copyright © 2015 František Kučera (frantovo.cz) |
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4 * |
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5 * This program is free software: you can redistribute it and/or modify |
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6 * it under the terms of the GNU General Public License as published by |
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7 * the Free Software Foundation, either version 3 of the License, or |
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8 * (at your option) any later version. |
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9 * |
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10 * This program is distributed in the hope that it will be useful, |
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11 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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13 * GNU General Public License for more details. |
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14 * |
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15 * You should have received a copy of the GNU General Public License |
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16 * along with this program. If not, see <http://www.gnu.org/licenses/>. |
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17 */ |
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18 package info.globalcode.sql.dk.jdbc; |
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19 |
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20 import info.globalcode.sql.dk.Constants; |
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21 import info.globalcode.sql.dk.configuration.Configuration; |
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22 import info.globalcode.sql.dk.configuration.ConfigurationException; |
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23 import info.globalcode.sql.dk.configuration.DatabaseDefinition; |
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24 import info.globalcode.sql.dk.configuration.Loader; |
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25 import info.globalcode.sql.dk.configuration.Properties; |
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26 import info.globalcode.sql.dk.configuration.Property; |
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27 import java.sql.Connection; |
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28 import java.sql.DriverManager; |
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29 import java.sql.DriverPropertyInfo; |
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30 import java.sql.SQLException; |
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31 import java.sql.SQLFeatureNotSupportedException; |
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32 import java.util.logging.Level; |
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33 import java.util.logging.Logger; |
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34 |
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35 /** |
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36 * <p> |
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37 * Meta JDBC driver that works as redirector/router. It loads SQL-DK's configuration file and |
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38 * instantiates a real JDBC connection (PostgreSQL, MariDB etc.) of given name. |
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39 * </p> |
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40 * |
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41 * <p> |
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42 * Raison d'être: user can define his/her database connections just once (in SQL-DK's configuration) |
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43 * and use them in many other programs – there is no need to define the connection (hostname, |
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44 * username, password, properties…) in each application again and again. User will simply connect to |
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45 * e.g. <code>jdbc:sql-dk://my-connection</code> and this driver reads parameters of |
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46 * <code>my-connection</code> from SQL-DK's configuration and returns real driver implementation. |
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47 * </p> |
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48 * |
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49 * <p> |
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50 * Of course, the real JDBC driver for given database is still needed on the class path. |
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51 * </p> |
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52 * |
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53 * <p> |
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54 * TODO: current version is quite heavy-weight, because it includes whole SQL-DK source tree. Some |
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55 * refactoring and separation is desired to provide more light-weight JDBC driver. However the |
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56 * public interface and behavior of this driver should remain unchanged. |
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57 * </p> |
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58 * |
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59 * @author Ing. František Kučera (frantovo.cz) |
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60 */ |
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61 public class Driver implements java.sql.Driver { |
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62 |
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63 private static final Logger log = Logger.getLogger(Driver.class.getName()); |
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64 |
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65 private final Loader loader = new Loader(); |
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66 |
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67 static { |
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68 try { |
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69 DriverManager.registerDriver(new Driver()); |
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70 } catch (SQLException e) { |
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71 log.log(Level.SEVERE, "Unable to register JDBC driver", e); |
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72 } |
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73 } |
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74 |
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75 @Override |
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76 public Connection connect(String url, java.util.Properties info) throws SQLException { |
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77 if (acceptsURL(url)) { |
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78 log.log(Level.FINER, "Loading SQL-DK configuration for URL: {0}", url); |
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79 String name = extractDatabaseName(url); |
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80 log.log(Level.FINE, "Loading SQL-DK configuration for name: {0}", name); |
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81 |
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82 try { |
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83 return getConnection(name, info); |
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84 } catch (ConfigurationException e) { |
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85 log.log(Level.SEVERE, "Unable to load SQL-DK configuration for name: {0}. Is it defined in {1}?", new Object[]{name, Constants.CONFIG_FILE}); |
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86 throw new SQLException("Unable to load SQL-DK configuration for name: " + name, e); |
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87 } |
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88 } else { |
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89 // The driver should return "null" if it realizes it is the wrong kind of driver to connect to the given URL. |
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90 return null; |
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91 } |
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92 } |
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93 |
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94 private Connection getConnection(String connectionName, java.util.Properties info) throws SQLException, ConfigurationException { |
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95 Configuration c = loader.loadConfiguration(); |
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96 DatabaseDefinition dd = c.getDatabase(connectionName); |
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97 |
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98 if (acceptsURL(dd.getUrl())) { |
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99 log.log(Level.SEVERE, "SQL-DK meta JDBC driver loops to itself: {0} → {1} Please check {2}", new Object[]{connectionName, dd.getUrl(), Constants.CONFIG_FILE}); |
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100 throw new ConfigurationException("SQL-DK meta JDBC driver loops to itself."); |
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101 } else { |
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102 return Loader.jdbcConnect(dd, translate(info)); |
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103 } |
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104 } |
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105 |
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106 private String extractDatabaseName(String url) { |
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107 return url.split("//", 2)[1]; |
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108 } |
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109 |
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110 /** |
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111 * TODO: refactor/move, reuse |
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112 * |
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113 * @param info |
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114 * @return |
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115 */ |
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116 private Properties translate(java.util.Properties info) { |
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117 Properties properties = new Properties(); |
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118 |
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119 for (String name : info.stringPropertyNames()) { |
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120 String value = info.getProperty(name); |
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121 properties.add(new Property(name, value)); |
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122 } |
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123 |
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124 return properties; |
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125 } |
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126 |
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127 @Override |
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128 public boolean acceptsURL(String url) throws SQLException { |
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129 return url != null && url.startsWith("jdbc:sql-dk://"); |
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130 } |
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131 |
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132 @Override |
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133 public DriverPropertyInfo[] getPropertyInfo(String url, java.util.Properties info) throws SQLException { |
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134 return new DriverPropertyInfo[0]; |
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135 } |
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136 |
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137 @Override |
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138 public int getMajorVersion() { |
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139 return 0; |
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140 } |
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141 |
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142 @Override |
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143 public int getMinorVersion() { |
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144 return 1; |
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145 } |
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146 |
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147 @Override |
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148 public boolean jdbcCompliant() { |
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149 return false; |
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150 } |
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151 |
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152 @Override |
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153 public Logger getParentLogger() throws SQLFeatureNotSupportedException { |
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154 throw new SQLFeatureNotSupportedException("Not supported yet."); |
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155 } |
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156 |
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157 } |