idea连接数据库是报错

Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:617)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:514)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

java.lang.NullPointerException
org.apache.jsp.checkUser_jsp._jspService(checkUser_jsp.java:136)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:476)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
):注意 主要问题的全部 stack 信息可以在 server logs 里查看

idea在连接数据库时在验证的时候报错

NullPointerException 是不是有配置没有配报空指针异常

看一下你的数据库配置的代码

private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/localhost:3306/db_user?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf-8";

你这个写错了吧，怎么有两个localhost:3306