JDBC自定義連接池
阿新 • • 發佈：2018-10-30
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最近學習了JDBC的相關知識，寫一下自定義連接池
一些說明：
本代碼參考了部分別人的代碼！！！
JDBCCon類具體創建了連接；
MyConnection類集成了Connection類用來管理連接與池，其中的close方法必須pool.add()；
MyDataSource則是具體實現連接池。
具體步驟：
1、導mysql的jar包
2、配置db.propertites
1 driver = com.mysql.cj.jdbc.Driver 2 url = jdbc:mysql://localhost:3306/test?serverTimezone=GMT 3 username = root 4 password = root
3、JDBCCon
1 package com.nick.util; 2 3 import java.io.IOException; 4 import java.io.InputStream; 5 import java.sql.Connection; 6 import java.sql.DriverManager; 7 import java.sql.PreparedStatement; 8 import java.sql.ResultSet; 9 import java.sql.SQLException; 10 import java.util.Properties;11 12 public class JDBCCon { 13 14 private static String driver; 15 private static String url; 16 private static String username; 17 private static String password; 18 19 20 static { 21 22 try { 23 ClassLoader classLoader = JDBCCon.class.getClassLoader();24 InputStream is = classLoader.getResourceAsStream("db.properties"); 25 Properties props = new Properties(); 26 props.load(is); 27 driver = props.getProperty("driver"); 28 url = props.getProperty("url"); 29 username = props.getProperty("username"); 30 password = props.getProperty("password"); 31 } catch (IOException e) { 32 // TODO Auto-generated catch block 33 e.printStackTrace(); 34 } 35 36 } 37 38 public static Connection getConnection() { 39 Connection connection = null; 40 try { 41 Class.forName(driver); 42 connection = DriverManager.getConnection(url, username, password); 43 } catch (Exception e) { 44 // TODO: handle exception 45 } 46 return connection; 47 48 } 49 50 public static void release(Connection conn, PreparedStatement pstmt, ResultSet rs) { 51 if(rs != null) { 52 try { 53 rs.close(); 54 } catch (SQLException e) { 55 // TODO Auto-generated catch block 56 e.printStackTrace(); 57 } 58 } 59 if(pstmt != null) { 60 try { 61 pstmt.close(); 62 } catch (SQLException e) { 63 // TODO Auto-generated catch block 64 e.printStackTrace(); 65 } 66 } 67 if(conn != null) { 68 try { 69 conn.close(); 70 } catch (SQLException e) { 71 // TODO Auto-generated catch block 72 e.printStackTrace(); 73 } 74 } 75 76 } 77 78 }
4、MyConnection
1 package com.nick.dataSource; 2 3 import java.sql.Array; 4 import java.sql.Blob; 5 import java.sql.CallableStatement; 6 import java.sql.Clob; 7 import java.sql.Connection; 8 import java.sql.DatabaseMetaData; 9 import java.sql.NClob; 10 import java.sql.PreparedStatement; 11 import java.sql.SQLClientInfoException; 12 import java.sql.SQLException; 13 import java.sql.SQLWarning; 14 import java.sql.SQLXML; 15 import java.sql.Savepoint; 16 import java.sql.Statement; 17 import java.sql.Struct; 18 import java.util.LinkedList; 19 import java.util.Map; 20 import java.util.Properties; 21 import java.util.concurrent.Executor; 22 23 public class MyConnection implements Connection{ 24 25 private Connection connection = null; 26 private LinkedList<Connection> pool = null; 27 public MyConnection(Connection connection, LinkedList<Connection> pool) { 28 this.connection = connection; 29 this.pool = pool; 30 } 31 32 @Override 33 public void close() throws SQLException { 34 // TODO Auto-generated method stub 35 pool.add(connection); 36 } 37 38 @Override 39 public <T> T unwrap(Class<T> iface) throws SQLException { 40 // TODO Auto-generated method stub 41 return null; 42 } 43 @Override 44 public boolean isWrapperFor(Class<?> iface) throws SQLException { 45 // TODO Auto-generated method stub 46 return false; 47 } 48 @Override 49 public Statement createStatement() throws SQLException { 50 // TODO Auto-generated method stub 51 return null; 52 } 53 @Override 54 public PreparedStatement prepareStatement(String sql) throws SQLException { 55 // TODO Auto-generated method stub 56 return null; 57 } 58 @Override 59 public CallableStatement prepareCall(String sql) throws SQLException { 60 // TODO Auto-generated method stub 61 return null; 62 } 63 @Override 64 public String nativeSQL(String sql) throws SQLException { 65 // TODO Auto-generated method stub 66 return null; 67 } 68 @Override 69 public void setAutoCommit(boolean autoCommit) throws SQLException { 70 // TODO Auto-generated method stub 71 72 } 73 @Override 74 public boolean getAutoCommit() throws SQLException { 75 // TODO Auto-generated method stub 76 return false; 77 } 78 @Override 79 public void commit() throws SQLException { 80 // TODO Auto-generated method stub 81 82 } 83 @Override 84 public void rollback() throws SQLException { 85 // TODO Auto-generated method stub 86 87 } 88 89 @Override 90 public boolean isClosed() throws SQLException { 91 // TODO Auto-generated method stub 92 return false; 93 } 94 @Override 95 public DatabaseMetaData getMetaData() throws SQLException { 96 // TODO Auto-generated method stub 97 return null; 98 } 99 @Override 100 public void setReadOnly(boolean readOnly) throws SQLException { 101 // TODO Auto-generated method stub 102 103 } 104 @Override 105 public boolean isReadOnly() throws SQLException { 106 // TODO Auto-generated method stub 107 return false; 108 } 109 @Override 110 public void setCatalog(String catalog) throws SQLException { 111 // TODO Auto-generated method stub 112 113 } 114 @Override 115 public String getCatalog() throws SQLException { 116 // TODO Auto-generated method stub 117 return null; 118 } 119 @Override 120 public void setTransactionIsolation(int level) throws SQLException { 121 // TODO Auto-generated method stub 122 123 } 124 @Override 125 public int getTransactionIsolation() throws SQLException { 126 // TODO Auto-generated method stub 127 return 0; 128 } 129 @Override 130 public SQLWarning getWarnings() throws SQLException { 131 // TODO Auto-generated method stub 132 return null; 133 } 134 @Override 135 public void clearWarnings() throws SQLException { 136 // TODO Auto-generated method stub 137 138 } 139 @Override 140 public Statement createStatement(int resultSetType, int resultSetConcurrency) throws SQLException { 141 // TODO Auto-generated method stub 142 return null; 143 } 144 @Override 145 public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency) 146 throws SQLException { 147 // TODO Auto-generated method stub 148 return null; 149 } 150 @Override 151 public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency) throws SQLException { 152 // TODO Auto-generated method stub 153 return null; 154 } 155 @Override 156 public Map<String, Class<?>> getTypeMap() throws SQLException { 157 // TODO Auto-generated method stub 158 return null; 159 } 160 @Override 161 public void setTypeMap(Map<String, Class<?>> map) throws SQLException { 162 // TODO Auto-generated method stub 163 164 } 165 @Override 166 public void setHoldability(int holdability) throws SQLException { 167 // TODO Auto-generated method stub 168 169 } 170 @Override 171 public int getHoldability() throws SQLException { 172 // TODO Auto-generated method stub 173 return 0; 174 } 175 @Override 176 public Savepoint setSavepoint() throws SQLException { 177 // TODO Auto-generated method stub 178 return null; 179 } 180 @Override 181 public Savepoint setSavepoint(String name) throws SQLException { 182 // TODO Auto-generated method stub 183 return null; 184 } 185 @Override 186 public void rollback(Savepoint savepoint) throws SQLException { 187 // TODO Auto-generated method stub 188 189 } 190 @Override 191 public void releaseSavepoint(Savepoint savepoint) throws SQLException { 192 // TODO Auto-generated method stub 193 194 } 195 @Override 196 public Statement createStatement(int resultSetType, int resultSetConcurrency, int resultSetHoldability) 197 throws SQLException { 198 // TODO Auto-generated method stub 199 return null; 200 } 201 @Override 202 public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency, 203 int resultSetHoldability) throws SQLException { 204 // TODO Auto-generated method stub 205 return null; 206 } 207 @Override 208 public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency, 209 int resultSetHoldability) throws SQLException { 210 // TODO Auto-generated method stub 211 return null; 212 } 213 @Override 214 public PreparedStatement prepareStatement(String sql, int autoGeneratedKeys) throws SQLException { 215 // TODO Auto-generated method stub 216 return null; 217 } 218 @Override 219 public PreparedStatement prepareStatement(String sql, int[] columnIndexes) throws SQLException { 220 // TODO Auto-generated method stub 221 return null; 222 } 223 @Override 224 public PreparedStatement prepareStatement(String sql, String[] columnNames) throws SQLException { 225 // TODO Auto-generated method stub 226 return null; 227 } 228 @Override 229 public Clob createClob() throws SQLException { 230 // TODO Auto-generated method stub 231 return null; 232 } 233 @Override 234 public Blob createBlob() throws SQLException { 235 // TODO Auto-generated method stub 236 return null; 237 } 238 @Override 239 public NClob createNClob() throws SQLException { 240 // TODO Auto-generated method stub 241 return null; 242 } 243 @Override 244 public SQLXML createSQLXML() throws SQLException { 245 // TODO Auto-generated method stub 246 return null; 247 } 248 @Override 249 public boolean isValid(int timeout) throws SQLException { 250 // TODO Auto-generated method stub 251 return false; 252 } 253 @Override 254 public void setClientInfo(String name, String value) throws SQLClientInfoException { 255 // TODO Auto-generated method stub 256 257 } 258 @Override 259 public void setClientInfo(Properties properties) throws SQLClientInfoException { 260 // TODO Auto-generated method stub 261 262 } 263 @Override 264 public String getClientInfo(String name) throws SQLException { 265 // TODO Auto-generated method stub 266 return null; 267 } 268 @Override 269 public Properties getClientInfo() throws SQLException { 270 // TODO Auto-generated method stub 271 return null; 272 } 273 @Override 274 public Array createArrayOf(String typeName, Object[] elements) throws SQLException { 275 // TODO Auto-generated method stub 276 return null; 277 } 278 @Override 279 public Struct createStruct(String typeName, Object[] attributes) throws SQLException { 280 // TODO Auto-generated method stub 281 return null; 282 } 283 @Override 284 public void setSchema(String schema) throws SQLException { 285 // TODO Auto-generated method stub 286 287 } 288 @Override 289 public String getSchema() throws SQLException { 290 // TODO Auto-generated method stub 291 return null; 292 } 293 @Override 294 public void abort(Executor executor) throws SQLException { 295 // TODO Auto-generated method stub 296 297 } 298 @Override 299 public void setNetworkTimeout(Executor executor, int milliseconds) throws SQLException { 300 // TODO Auto-generated method stub 301 302 } 303 @Override 304 public int getNetworkTimeout() throws SQLException { 305 // TODO Auto-generated method stub 306 return 0; 307 } 308 }
5、MyDataSource
1 package com.nick.dataSource; 2 3 import java.sql.Connection; 4 import java.util.LinkedList; 5 6 import com.nick.util.JDBCCon; 7 8 public class MyDataSource { 9 10 private static LinkedList<Connection> pool = new LinkedList<Connection>(); 11 12 static { 13 // 14 for(int i = 0; i < 5; i++) { 15 Connection connection = JDBCCon.getConnection(); 16 pool.add(connection); 17 } 18 } 19 20 public static Connection getConnection() { 21 if(pool.size() == 0) { 22 for(int i = 0; i < 5; i++) { 23 Connection connection = JDBCCon.getConnection(); 24 MyConnection myConnection = new MyConnection(connection, pool); 25 pool.add(myConnection); 26 } 27 } 28 Connection connection = pool.remove(0); 29 return connection; 30 31 } 32 }
6、檢測代碼
1 package com.nick.test; 2 3 import java.sql.Connection; 4 import java.sql.PreparedStatement; 5 6 import org.junit.jupiter.api.Test; 7 8 import com.nick.dataSource.MyDataSource; 9 import com.nick.util.JDBCCon; 10 11 public class TestDemo01 { 12 13 @Test 14 public void t1() { 15 Connection connection = null; 16 PreparedStatement pstmt = null; 17 MyDataSource myDataSource = new MyDataSource(); 18 try { 19 connection = myDataSource.getConnection(); 20 String sql = "insert into student values (?,?,?,?)"; 21 PreparedStatement prepareStatement = connection.prepareStatement(sql); 22 prepareStatement.setInt(1, 10); 23 prepareStatement.setString(2, "呂布"); 24 prepareStatement.setString(3, "男"); 25 prepareStatement.setInt(4, 100); 26 int rows = prepareStatement.executeUpdate(); 27 if(rows > 0) { 28 System.out.println("OK"); 29 }else { 30 System.out.println("NO"); 31 } 32 } catch (Exception e) { 33 // TODO: handle exception 34 } 35 } 36 }
以上即全部代碼。
JDBC自定義連接池