package nankang.test;import java.sql.Connection;import com.mchange.v2.c3p0.ComboPooledDataSource;public class ConnectionFactory {    private static ComboPooledDataSource ds = null;    static {        try {            String driver = "oracle.jdbc.driver.OracleDriver";            String url = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";            String user = "phonesurvey";            String password = "world";            ds = new ComboPooledDataSource();            ds.setDriverClass(driver);            ds.setJdbcUrl(url);            ds.setUser(user);            ds.setPassword(password);            ds.setMaxPoolSize(200);            ds.setMinPoolSize(20);        } catch (Exception e) {            e.printStackTrace();        }    }        public static synchronized Connection getConnection(){        Connection conn = null;        try{            conn = ds.getConnection();        }catch(Exception e){            e.printStackTrace();        }        return conn;    }        }

package nankang.test;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;public class Main {    /**     * @param args     */    public static void main(String[] args) {        Connection conn = null;        PreparedStatement pstm = null;        ResultSet rs = null;        try {            conn = ConnectionFactory.getConnection();            String sql = "select * from Agent";            pstm = conn.prepareStatement(sql);            rs = pstm.executeQuery();            while (rs.next()) {                String agentId = rs.getString("AgentId");                System.out.println(agentId);            }            System.out.println("成功");        } catch (Exception e) {            System.out.println(String.format("失败，%s", e.getMessage()));        } finally {            if (rs != null) {                try {                    rs.close();                } catch (Exception e) {                    e.printStackTrace();                }            }            if (pstm != null) {                try {                    pstm.close();                } catch (Exception e) {                    e.printStackTrace();                }            }            if (conn != null) {                try {                    conn.close();                } catch (Exception e) {                    e.printStackTrace();                }            }        }    }}