在下载了jdbc连接器并将该库添加到eclipse之后,我试图用Java连接数据库,但是仍然抓住了我一个java.lang.NullPointerException
。我正在尝试从已经创建的数据库中读取一个简单的表。
public class DBConnect
{
private Connection con;
private Statement st;
private ResultSet rs;
public DBConnect()
{
try
{
Class.forName( "com.mysql.jdbc.Driver" );
DriverManager.getConnection( "jdbc:mysql://localhost:3306/exp", "root", "" );
st = con.createStatement();
System.out.println( "OK" );
}
catch ( Exception e )
{
System.out.println( e );
}
}