服务器端用jdbc连接数据库,结果出现这样的错误:
org.apache.catalina.core.StandardWrapperValve invoke
??: Servlet.service() for servlet [LoginServlet] in context with path [/BBStuServlet] threw exception
java.lang.NullPointerException
at com.roy.bbstuservlet.JDBConnection.executeQuery(JDBConnection.java:61)
我查看61行的代码:
Statement stmt = con.createStatement();
这一行是创建Statement对象用来执行数据库操作的,怎么会错呢?求前辈指教