1 import org.apache.commons.logging.Log;
  2 import org.apache.commons.logging.LogFactory;
  3
  4 import javax.sql.DataSource;
  5 import java.util.Collections;
  6 import java.util.LinkedList;
  7 import java.sql.Connection;
  8 import java.sql.SQLException;
  9 import java.sql.DriverManager;
 10 import java.io.PrintWriter;
 11
 12 /**
 13 * 一个简单的DataSource实现
 14 *
 15 * @author leizhimin 2010-1-14 0:03:17
 16 */
 17 public class SimpleDateSource implements DataSource {
 18         private static Log log = LogFactory.getLog(SimpleDateSource.class);
 19         private static final String dirverClassName = "com.mysql.jdbc.Driver";
 20         private static final String url = "jdbc:mysql://127.0.0.1:3306/testdb";
 21         private static final String user = "root";
 22         private static final String pswd = "leizhimin";
 23         //连接池
 24         private static LinkedList<Connection> pool = (LinkedList<Connection>) Collections.synchronizedList(new LinkedList<Connection>());
 25         private static SimpleDateSource instance = new SimpleDateSource();
 26
 27         static {
 28                 try {
 29                         Class.forName(dirverClassName);
 30                 } catch (ClassNotFoundException e) {
 31                         log.error("找不到驱动类！", e);
 32                 }
 33         }
 34
 35         private SimpleDateSource() {
 36         }
 37
 38         /**
 39          * 获取数据源单例
 40          *
 41          * @return 数据源单例
 42          */
 43         public SimpleDateSource instance() {
 44                 if (instance == null) instance = new SimpleDateSource();
 45                 return instance;
 46         }
 47
 48         /**
 49          * 获取一个数据库连接
 50          *
 51          * @return 一个数据库连接
 52          * @throws SQLException
 53          */
 54         public Connection getConnection() throws SQLException {
 55                 synchronized (pool) {
 56                         if (pool.size() > 0) return pool.removeFirst();
 57                         else return makeConnection();
 58                 }
 59         }
 60
 61         /**
 62          * 连接归池
 63          *
 64          * @param conn
 65          */
 66         public static void freeConnection(Connection conn) {
 67                 pool.addLast(conn);
 68         }
 69
 70         private Connection makeConnection() throws SQLException {
 71                 return DriverManager.getConnection(url, user, pswd);
 72         }
 73
 74         public Connection getConnection(String username, String password) throws SQLException {
 75                 return DriverManager.getConnection(url, username, password);
 76         }
 77
 78         public PrintWriter getLogWriter() throws SQLException {
 79                 return null;
 80         }
 81
 82         public void setLogWriter(PrintWriter out) throws SQLException {
 83
 84         }
 85
 86         public void setLoginTimeout(int seconds) throws SQLException {
 87
 88         }
 89
 90         public int getLoginTimeout() throws SQLException {
 91                 return 0;
 92         }
 93
 94         public <T> T unwrap(Class<T> iface) throws SQLException {
 95                 return null;
 96         }
 97
 98         public boolean isWrapperFor(Class<?> iface) throws SQLException {
 99                 return false;
100         }
101 }