Question

jsp连接Oracle读取表提示错误，求指导

type Exception report

message java.lang.NullPointerException

description The server encountered an internal error that prevented
it from fulfilling this request.

exception
org.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:549)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:470)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

root cause
java.lang.NullPointerException
org.apache.jsp.showAllBooks_jsp._jspService(showAllBooks_jsp.java:92)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

note The full stack trace of the root cause is available in the
Apache Tomcat/7.0.30 logs.

Answer 1

空指针的原因有很大一部分原因是你的sql语句写错了，检查检查吧，要不就把编码贴出来啊

Answer 2

空指针，可能是读数据库字段遇到空数据了，那字段确实没数据的话，可以忽略这个错误不理，程序里弄个默认值。

Answer 3

具体showAllBooks。jsp 文件贴出来啊。

只能看到空指针。基本上断定 jsp 编写错误。