if (numcl.equals("ON")) { out.println("相同"); } else { out.println("不同");} %>按照楼上的方法我又添加了一个else语法。结果如果选择的话输出正确,但是如果不选择的话结果执行2.jsp的时候出错。 null java.lang.NullPointerException at jrun__index2ejspa._jspService(jrun__index2ejspa.java:86) at allaire.jrun.jsp.HttpJSPServlet.service(HttpJSPServlet.java:40) at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1013) at allaire.jrun.servlet.JRunSE.runServlet(JRunSE.java:925) at allaire.jrun.servlet.JRunNamedDispatcher.forward(JRunNamedDispatcher.java:34) at allaire.jrun.jsp.JSPServlet.service(JSPServlet.java:175) at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1013) at allaire.jrun.servlet.JRunSE.runServlet(JRunSE.java:925) at allaire.jrun.servlet.JRunRequestDispatcher.forward(JRunRequestDispatcher.java:88) at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1131) at allaire.jrun.servlet.JvmContext.dispatch(JvmContext.java:330) at allaire.jrun.http.WebEndpoint.run(WebEndpoint.java:107) at allaire.jrun.ThreadPool.run(ThreadPool.java:272) at allaire.jrun.WorkerThread.run(WorkerThread.java:75)
String num2; numcl=request.getParameter("C1"); if (numcl==null) numcl="";
if (numcl.equals("ON")) { out.println("相同"); } else { out.println("不同");}
String num2;
numcl=request.getParameter("C1");
if (numcl.equals("ON"))
{ out.println("相同"); }
else
{ out.println("不同");}
%>按照楼上的方法我又添加了一个else语法。结果如果选择的话输出正确,但是如果不选择的话结果执行2.jsp的时候出错。
null
java.lang.NullPointerException
at jrun__index2ejspa._jspService(jrun__index2ejspa.java:86)
at allaire.jrun.jsp.HttpJSPServlet.service(HttpJSPServlet.java:40)
at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1013)
at allaire.jrun.servlet.JRunSE.runServlet(JRunSE.java:925)
at allaire.jrun.servlet.JRunNamedDispatcher.forward(JRunNamedDispatcher.java:34)
at allaire.jrun.jsp.JSPServlet.service(JSPServlet.java:175)
at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1013)
at allaire.jrun.servlet.JRunSE.runServlet(JRunSE.java:925)
at allaire.jrun.servlet.JRunRequestDispatcher.forward(JRunRequestDispatcher.java:88)
at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1131)
at allaire.jrun.servlet.JvmContext.dispatch(JvmContext.java:330)
at allaire.jrun.http.WebEndpoint.run(WebEndpoint.java:107)
at allaire.jrun.ThreadPool.run(ThreadPool.java:272)
at allaire.jrun.WorkerThread.run(WorkerThread.java:75)
numcl=request.getParameter("C1");
if (numcl==null)
numcl="";
if (numcl.equals("ON"))
{ out.println("相同"); }
else
{ out.println("不同");}