麻烦大家帮忙看看一下问题所在,谢谢了

Question

java.lang.NullPointerException at java.util.Properties$LineReader.readLine(Properties.java:434) at java.util.Properties.load0(Properties.java:353) at java.util.Properties.load(Properties.java:341) at dao.CommDAO.<clinit>(CommDAO.java:47) at org.apache.jsp.welcome_jsp._jspService(welcome_jsp.java:124) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at util.SetChar.doFilter(SetChar.java:26) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:958) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:452) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1087) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2517) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2506) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '5 * from notice order by savetime desc' at line 1--select top 5 * from notice order by savetime desc  at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:936) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2934) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1616) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1708) at com.mysql.jdbc.Connection.execSQL(Connection.java:3249) at com.mysql.jdbc.Connection.execSQL(Connection.java:3178) at com.mysql.jdbc.Statement.executeQuery(Statement.java:1203) at dao.CommDAO.select(CommDAO.java:165) at org.apache.jsp.welcome_jsp._jspService(welcome_jsp.java:128) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at util.SetChar.doFilter(SetChar.java:26) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:958) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:452) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1087) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2517) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2506) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)--select top 6 * from sysuser where utype='医生' order by id desc com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '6 * from sysuser where utype='??' order by id desc' at line 1 at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:936) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2934) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1616) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1708) at com.mysql.jdbc.Connection.execSQL(Connection.java:3249) at com.mysql.jdbc.Connection.execSQL(Connection.java:3178) at com.mysql.jdbc.Statement.executeQuery(Statement.java:1203) at dao.CommDAO.select(CommDAO.java:165) at org.apache.jsp.welcome_jsp._jspService(welcome_jsp.java:166) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at util.SetChar.doFilter(SetChar.java:26) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:958) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:452) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1087) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2517) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2506) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '5 * from notice order by savetime desc' at line 1 at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:936) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2934) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1616) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1708) at com.mysql.jdbc.Connection.execSQL(Connection.java:3249) at com.mysql.jdbc.Connection.execSQL(Connection.java:3178) at com.mysql.jdbc.Statement.executeQuery(Statement.java:1203) at dao.CommDAO.select(CommDAO.java:165) at org.apache.jsp.welcome_jsp._jspService(welcome_jsp.java:128) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at util.SetChar.doFilter(SetChar.java:26) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:958) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:452) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1087) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2517) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2506) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '6 * from sysuser where utype='??' order by id desc' at line 1 at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:936) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2934) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1616) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1708) at com.mysql.jdbc.Connection.execSQL(Connection.java:3249) at com.mysql.jdbc.Connection.execSQL(Connection.java:3178) at com.mysql.jdbc.Statement.executeQuery(Statement.java:1203) at dao.CommDAO.select(CommDAO.java:165) at org.apache.jsp.welcome_jsp._jspService(welcome_jsp.java:166) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at util.SetChar.doFilter(SetChar.java:26) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:958) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:452) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1087) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2517) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2506) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)--select top 5 * from notice order by savetime desc --select top 6 * from sysuser where utype='医生' order by id desc 

Answer 1

你的sql语句有错误，看样子你用的应该是mysql吧，mysql里不支持top

Answer 2

空指针异常，没代码怎么看