mysql使用连接池的示例：
1.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);
}
}
2.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>
3.使用配置文件。
/*** 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);
}
}
