c3p0 mysql 例子

import java.sql.*; import javax.sql.DataSource; import com.mchange.v2.c3p0.DataSources; public final class UsePoolBackedDataSource { public static void main(String[] argv) { try { /* 创建库和测试数据 create database x; use x; create table y (z int); insert y (z) values (1); insert y (z) values (2); insert y (z) values (3); * */ Class.forName("com.mysql.jdbc.Driver"); DataSource unpooled = DataSources.unpooledDataSource("jdbc:mysql://localhost:3306/x", "root","3"); //用户名root,密码是2,你的密码如果不是2,请填写你的密码,如果是空,请修改一下 //语句如下: set password for root@localhost=password('3'); DataSource pooled = DataSources.pooledDataSource( unpooled ); // get hold of a Connection an do stuff, in the usual way Connection con = null; Statement stmt = null; ResultSet rs = null; try { con = pooled.getConnection(); System.out.println("下面是输出:"); stmt = con.createStatement(); rs = stmt.executeQuery("SELECT * FROM y"); while (rs.next()) System.out.println( rs.getString(1) ); } finally { attemptClose(rs); attemptClose(stmt); attemptClose(con); } } catch (Exception e) { e.printStackTrace(); } } static void attemptClose(ResultSet o) { try { if (o != null) o.close();} catch (Exception e) { e.printStackTrace();} } static void attemptClose(Statement o) { try { if (o != null) o.close();} catch (Exception e) { e.printStackTrace();} } static void attemptClose(Connection o) { try { if (o != null) o.close();} catch (Exception e) { e.printStackTrace();} } private UsePoolBackedDataSource() {} }