javaweb注册验证，错误在哪

Question

严重: Servlet.service() for servlet [regServlet] in context with path [/test_user] threw exception
java.lang.NullPointerException
at com.yadong.domain.UserForm.validate(UserForm.java:39)
at com.yadong.web.servlet.regServlet.doGet(regServlet.java:36)
at com.yadong.web.servlet.regServlet.doPost(regServlet.java:89)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2441)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2430)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)

Answer 1

com.yadong.domain.UserForm.validate(UserForm.java:39)。UseForm的39行是什么代码？？？

Answer 2

39     if（repassword.equals(password)）｛
40        msg.put(“repassword”,“两次密码不一致”) 41      ｝

Answer 3

39     if（repassword.equals(password)）｛
40        msg.put(“repassword”,“两次密码不一致”) 41      ｝
repassword为null,可以在前面打印一下看一下

Answer 4

39     if（repassword.equals(password)）｛
40        msg.put(“repassword”,“两次密码不一致”) 41      ｝
repassword为null,可以在前面打印一下看一下
可以了，太谢谢了，那为什么网上教学的它视频里面代码可以啊