Question

javax.servlet.ServletException: BeanUtils.populate

这是什么异常啊
javax.servlet.ServletException: BeanUtils.populate
org.apache.struts.util.RequestUtils.populate(RequestUtils.java:1254)
org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:821)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:254)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
com.exam.struts.form.CharFilter.doFilter(CharFilter.java:28)

root cause

java.lang.NullPointerException
org.apache.commons.beanutils.PropertyUtils.setIndexedProperty(PropertyUtils.java:1458)
org.apache.commons.beanutils.BeanUtils.setProperty(BeanUtils.java:1013)
org.apache.commons.beanutils.BeanUtils.populate(BeanUtils.java:808)
org.apache.struts.util.RequestUtils.populate(RequestUtils.java:1252)
org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:821)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:254)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
com.exam.struts.form.CharFilter.doFilter(CharFilter.java:28)

Answer 1

NullPointerException 是空指针异常，用Servlet要throws Exception