<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config><!-- 这是默认配置信息 --><default-config><!-- 连接四大参数配置 --><property name="jdbcUrl">jdbc:mysql://localhost:3306/tb_test</property><property name="driverClass">com.mysql.jdbc.Driver</property><property name="user">root</property><property name="password">root</property><!-- 池参数配置 --><property name="acquireIncrement">3</property><property name="initialPoolSize">10000</property><property name="minPoolSize">10</property><property name="maxPoolSize">10</property><property name="defaultAutoCommit" value="false"/><property name="maxIdle" value="5"/><property name="minIdle" value="1"/><property name="maxActive" value="40"/><property name="removeAbandoned" value="true"/><property name="removeAbandonedTimeout" value="180"/><property name="maxWait" value="15000"/><property name="timeBetweenEvictionRunsMillis" value="120000"/><property name="minEvictableIdleTimeMillis" value="300000"/></default-config>
</c3p0-config>

三丶写一个数据库连接池c3p0的工具类

    private  static  Connection connection;//定义一个连接private  static ComboPooledDataSource dataSource = new ComboPooledDataSource();//创建一个数据库连接池public static  Connection getConnection(){//从数据库连接池中获取连接try {connection=dataSource.getConnection();//获取到一个连接} catch (SQLException e) {e.printStackTrace();}return  connection;}

四丶测试

    public static void main(String[] args) {Connection connection = c3p0Util.getConnection();//调用c3p0工具类中获取连接方法try {Statement statement = connection.createStatement();ResultSet set = statement.executeQuery("select * from  tb_dept");while (set.next()){System.out.println(set.getString("deptno")+" "+set.getString("dname")+" "+set.getString("loc"));}} catch (SQLException e) {e.printStackTrace();}}