C3P0连接池的使用方法

1. 首先要导入C3P0的jar包

下载地址

https://download.csdn.net/download/lingxing9454/10655322

不要忘记导入MySql的jar包

2. 导入配置文件

配置文件名称必须为：c3p0-config.xml

配置文件格式如下：

要放在Src中 否则会报错

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>

  <default-config>
    <property name="driverClass">com.mysql.jdbc.Driver</property>
	<property name="jdbcUrl">jdbc:mysql://localhost:3306/数据库名称</property>
	<property name="user">root</property>
	<property name="password">root</property>
	<property name="initialPoolSize">5</property>
	<property name="maxPoolSize">20</property>
  </default-config>
  
  <named-config name="oracle"> 
    <property name="driverClass">com.mysql.jdbc.Driver</property>
	<property name="jdbcUrl">jdbc:mysql://localhost:3306/数据库名称</property>
	<property name="user">root</property>
	<property name="password">root</property>
  </named-config>
  

</c3p0-config>
           

3. 编写C3P0工具类

public class C3P0Utils {
	public static ComboPooledDataSource pd = new ComboPooledDataSource();
	
	public static DataSource getDataSource() {
		return pd;
	}
	
	public static Connection getConnection() {
		try {
			return pd.getConnection();
		} catch (SQLException e) {
			throw new RuntimeException(e);
		}
	}
	
    public static void close(Connection conn,PreparedStatement pst,ResultSet rs){ 
        if(rs!=null){ 
            try { 
                rs.close(); 
            } catch (SQLException e) { 
                e.printStackTrace(); 
            } 
        } 
        if(pst!=null){ 
            try { 
                pst.close(); 
            } catch (SQLException e) { 
               e.printStackTrace(); 
            } 
        } 
 
        if(conn!=null){ 
            try { 
                conn.close(); 
            } catch (SQLException e) { 
                e.printStackTrace(); 
            } 
        } 
    } 
}
           

4.测试C3P0！

public class UnitTest {
	
	@Test
	public void TestUnit() {
		
        Connection connection=C3P0Utils.getConnection();
        System.out.println(connection);
	}
}
           

输出 [email protected] 则证明可以使用C3P0