javaweb 中的连接池出错

Question

出错提示

javax.naming.NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file: java.naming.factory.initial
下面是我的测试的类

```public class myConn {
Connection conn;

// 初始化创建连接
public myConn() {
    Context ic;

    try {
        ic = new InitialContext();
        DataSource s = (DataSource) ic.lookup("java:comp/env/jdbc/conn");
        conn = s.getConnection();
    } catch (NamingException e) {
        e.printStackTrace();
    } catch (SQLException e) {
        e.printStackTrace();
    }

}

// 外界得到连接
public Connection getConnection() {
    return conn;
}

// 外界关闭数据库连接
public void closeConn() {
    try {
        conn.close();
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        System.out.println("数据库连接关闭失败");
    }
}

}

这是tomcat的context中的配置
name="jdbc/conn"
auth="Container"
type="javax.sql.DataSource"
factory="org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory"
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/exchange"
username="root" password="500235"
maxActive="20" maxIdle="10" maxWait="1000"
/>

这是tomcat的web配置

exchange DataSource
jdbc/conn
javax.sql.DataSource
Container

Answer 1

需要在环境或系统中指定类名，或者一个子程序参数，或者在应用程序资源文件中初始化～