使用MySQL连接池
手动配置连接池:
/** * 手动设置连接池 */ public void demo1(){ // 获得连接: Connection conn = null; PreparedStatement pstmt = null; ResultSet rs = null; try{ // 创建连接池: ComboPooledDataSource dataSource = new ComboPooledDataSource(); // 设置连接池的参数: dataSource.setDriverClass("com.mysql.jdbc.Driver"); dataSource.setJdbcUrl("jdbc:mysql:///jdbctest"); dataSource.setUser("root"); dataSource.setPassword("abc"); dataSource.setMaxPoolSize(20); dataSource.setInitialPoolSize(3); // 获得连接: conn = dataSource.getConnection(); // 编写Sql: String sql = "select * from user"; // 预编译SQL: pstmt = conn.prepareStatement(sql); // 设置参数 // 执行SQL: rs = pstmt.executeQuery(); while(rs.next()){ System.out.println(rs.getInt("uid")+" "+rs.getString("username")+" "+rs.getString("password")+" "+rs.getString("name")); } }catch(Exception e){ e.printStackTrace(); }finally{ JDBCUtils.release(rs, pstmt, conn); } }
使用配置文件配置连接池:
配置文件xml如下:
<?xml version="1.0" encoding="UTF-8"?> <c3p0-config> <default-config> <property name="driverClass">com.mysql.jdbc.Driver</property> <property name="jdbcUrl">jdbc:mysql:///jdbctest</property> <property name="user">root</property> <property name="password">abc</property> <property name="initialPoolSize">5</property> <property name="maxPoolSize">20</property> </default-config> </c3p0-config>
代码如下:
/** * 使用配置文件的方式 */ public void demo2(){ Connection conn = null; PreparedStatement pstmt = null; ResultSet rs = null; try{ /*// 获得连接: ComboPooledDataSource dataSource = new ComboPooledDataSource();*/ // 获得连接: // conn = dataSource.getConnection(); conn = JDBCUtils2.getConnection(); // 编写Sql: String sql = "select * from user"; // 预编译SQL: pstmt = conn.prepareStatement(sql); // 设置参数 // 执行SQL: rs = pstmt.executeQuery(); while(rs.next()){ System.out.println(rs.getInt("uid")+" "+rs.getString("username")+" "+rs.getString("password")+" "+rs.getString("name")); } }catch(Exception e){ e.printStackTrace(); }finally{ JDBCUtils2.release(rs, pstmt, conn); } }