Java中使用C3P0连接池

1、c3p0.properties
    c3p0.driverClass=org.postgresql.Driver
    c3p0.jdbcUrl=jdbc:postgresql://192.168.20.33:5432/kwtmap
    c3p0.user=nwd
    c3p0.password=ok123456
    c3p0.minPoolSize=5
    c3p0.maxPoolSize=20
    c3p0.acquireIncrement=5
    c3p0.initialPoolSize=5
    c3p0.maxIdleTime=240
2、Java代码
   

package com.boonya.mongo.optimize;  
    import java.beans.PropertyVetoException;  
    import java.sql.Connection;  
    import java.sql.SQLException;  
    import com.boonya.mongo.utils.ConstantUtils;  
    import com.mchange.v2.c3p0.ComboPooledDataSource;  
    /** 
     * MDBManager.java 
     * 功能：使用C3P0连接池获取数据库连接对象 
     * @author boonya 
     * @version 1.0 2013-03-07 
     */  
    public class MDBManager {  
          
        private static final MDBManager instance=new MDBManager();  
        private static ComboPooledDataSource cpds=new   ComboPooledDataSource(true);   
          
        /** 
         * 此处可以不配置，采用默认也行 
         */  
        static{  
            cpds.setDataSourceName("mydatasource");  
            cpds.setJdbcUrl(ConstantUtils.getValue("c3p0.jdbcUrl").toString());  
            try {  
                cpds.setDriverClass(ConstantUtils.getValue("c3p0.driverClass").toString());  
            } catch (PropertyVetoException e) {  
                e.printStackTrace();  
            }  
            cpds.setUser(ConstantUtils.getValue("c3p0.user").toString());  
            cpds.setPassword(ConstantUtils.getValue("c3p0.password").toString());  
            cpds.setMaxPoolSize(Integer.valueOf(ConstantUtils.getValue("c3p0.maxPoolSize").toString()));  
            cpds.setMinPoolSize(Integer.valueOf(ConstantUtils.getValue("c3p0.minPoolSize").toString()));  
            cpds.setAcquireIncrement(Integer.valueOf(ConstantUtils.getValue("c3p0.acquireIncrement").toString()));  
            cpds.setInitialPoolSize(Integer.valueOf(ConstantUtils.getValue("c3p0.initialPoolSize").toString()));  
            cpds.setMaxIdleTime(Integer.valueOf(ConstantUtils.getValue("c3p0.maxIdleTime").toString()));  
        }  
          
        private MDBManager(){}  
          
        public static MDBManager getInstance(){  
            return instance;  
        }  
          
        public static Connection  getConnection(){  
            try {  
                return cpds.getConnection();  
            } catch (SQLException e) {  
                e.printStackTrace();  
            }  
            return null;  
        }  
      
    }