报错ResultSet res=newuse.select(master);

qq_39459185 2017-09-19 07:22:31

<%@page import="java.sql.ResultSet"%>
<%@page import="com.dao.enty.MasterDao"%>
<%@page import="com.dao.impl.daoImpl"%>
<%@page import="com.dao.interfac.NewUseDao"%>
<%@page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
</head>
<body>
<%
request.setCharacterEncoding("utf-8");
NewUseDao newuse=new daoImpl();
MasterDao master=new MasterDao();
master.setId(1);
out.print(master.getId());
ResultSet res=newuse.select(master); /*报错行*/
while(res.next()){
out.print(res.getString("name"));
}
%>
</body>
</html>

报错显示没连上数据库，但是这段代码我放在java中是可以拿到数据库数据的，求解
Stacktrace:] with root cause
java.lang.NullPointerException
at com.dao.util.BaseDao.ExecuteQuery(BaseDao.java:85)
at com.dao.impl.daoImpl.select(daoImpl.java:30)
at org.apache.jsp.p216login_jsp._jspService(p216login_jsp.java:141)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:444)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:385)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:329)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:282)
at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:279)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAsPrivileged(Unknown Source)
at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:314)
at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:170)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:225)
at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:47)
at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:149)
at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:145)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:282)
at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:279)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAsPrivileged(Unknown Source)
at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:314)
at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:253)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:191)
at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:47)
at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:149)
at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:145)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:475)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:651)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:498)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:796)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1374)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)

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