DBCP模板

import java.io.FileNotFoundException;    import java.io.IOException;    import java.sql.Connection;    import java.sql.DriverManager;    import java.sql.ResultSet;    import java.sql.SQLException;    import java.sql.Statement;       import org.apache.commons.dbcp.ConnectionFactory;    import org.apache.commons.dbcp.DriverManagerConnectionFactory;    import org.apache.commons.dbcp.PoolableConnectionFactory;    import org.apache.commons.dbcp.PoolingDriver;    import org.apache.commons.pool.ObjectPool;    import org.apache.commons.pool.impl.GenericObjectPool;          public class PoolManager {          private static String                 driver="com.mysql.jdbc.Driver",//驱动                url = "jdbc:mysql://localhost:3306/test",//URL                Name="root",//用户名                Password="ssg";//密码                private static Class driverClass = null;        private static ObjectPool connectionPool = null;           public PoolManager(){               }                   /**        * 装配配置文件        * initProperties            */       private static void loadProperties(){            try {                java.io.InputStream stream = new java.io.FileInputStream("config(DBCP).properties");                java.util.Properties props = new java.util.Properties();                props.load(stream);                                driver = props.getProperty("driverClassName");                url = props.getProperty("url");                Name = props.getProperty("username");                Password = props.getProperty("password");                            } catch (FileNotFoundException e) {                System.out.println("读取配置文件异常");                     } catch(IOException ie){                System.out.println("读取配置文件时IO异常");            }        }                /**         * 初始化数据源         */         private static synchronized void initDataSource() {                     if (driverClass == null) {                 try {                     driverClass = Class.forName(driver);                 } catch (ClassNotFoundException e) {                     e.printStackTrace();                }             }         }              /**         * 连接池启动         * @throws Exception         */         public static void StartPool() {            loadProperties();            initDataSource();             if (connectionPool != null) {                 ShutdownPool();             }              try {                 connectionPool = new GenericObjectPool(null);                 ConnectionFactory connectionFactory = new DriverManagerConnectionFactory(url, Name, Password);                 PoolableConnectionFactory poolableConnectionFactory = new PoolableConnectionFactory(connectionFactory, connectionPool, null, null, false, true);                 Class.forName("org.apache.commons.dbcp.PoolingDriver");                 PoolingDriver driver = (PoolingDriver) DriverManager.getDriver("jdbc:apache:commons:dbcp:");                 driver.registerPool("dbpool", connectionPool);                              System.out.println("装配连接池OK");             } catch (Exception e) {                 e.printStackTrace();            }         }              /**         * 释放连接池         */         public static void ShutdownPool() {             try {                 PoolingDriver driver = (PoolingDriver) DriverManager.getDriver("jdbc:apache:commons:dbcp:");                 driver.closePool("dbpool");            } catch (SQLException e) {                 e.printStackTrace();            }         }                  /**         * 取得连接池中的连接         * @return         */         public static Connection getConnection() {             Connection conn = null;             if(connectionPool == null)                 StartPool();             try {                 conn = DriverManager.getConnection("jdbc:apache:commons:dbcp:dbpool");             } catch (SQLException e) {                 e.printStackTrace();            }             return conn;         }                 /**        * 获取连接        * getConnection        * @param name        * @return        */       public static Connection getConnection(String name){            return getConnection();        }        /**        * 释放连接        * freeConnection        * @param conn        */       public static void freeConnection(Connection conn){            if(conn != null){                try {                    conn.close();                } catch (SQLException e) {                                  e.printStackTrace();                }            }        }        /**        * 释放连接        * freeConnection        * @param name        * @param con        */       public static void freeConnection (String name,Connection con){            freeConnection(con);        }                /**        * 例子        * main        * @param args        */       public static void main(String[] args) {                    try {                Connection conn = PoolManager.getConnection();                if(conn != null){                    Statement statement = conn.createStatement();                    ResultSet rs = statement.executeQuery("select * from myuser");                    int c = rs.getMetaData().getColumnCount();                    while(rs.next()){                                           System.out.println();                        for(int i=1;i<=c;i++){                            System.out.print(rs.getObject(i));                        }                    }                    rs.close();                    statement.close();            }                PoolManager.freeConnection(conn);            } catch (SQLException e) {                          e.printStackTrace();            }           }       }