java.lang.NullPointerException at org.apache.jsp.index_jsp._jspService(index_jsp.java:98)java.lang.NullPointerException at org.apache.jsp.index_jsp._jspService(index_jsp.java:98)

java.lang.NullPointerException at org.apache.jsp.index_jsp._jspService(index_jsp.java:98)java.lang.NullPointerException at org.apache.jsp.index_jsp._jspService(index_jsp.java:98)
java.lang.NullPointerException at org.apache.jsp.index_jsp._jspService(index_jsp.java:98)
java.lang.NullPointerException
at org.apache.jsp.index_jsp._jspService(index_jsp.java:98)

java.lang.NullPointerException at org.apache.jsp.index_jsp._jspService(index_jsp.java:98)java.lang.NullPointerException at org.apache.jsp.index_jsp._jspService(index_jsp.java:98)
估计是PageBean pb = (PageBean)session.getAttribute("pb");这句话,pb没获取到,也就是pb的值是null,你可以打断点看一下,或者直接输出一下pb,看看是不是null.
如果是null,把你像session中赋值的语句部分发一下