错误提示如下,请问如何解决?
description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: An exception occurred processing JSP page /liuyan2.jsp at line 2219: temp1=request.getParameter("txttit");
20: temp2=request.getParameter("txtaut");
21: temp3=request.getParameter("txtart");
22: n=temp1.length()*temp2.length()*temp3.length();
23: if(n!=0){
24: temp=(String)application.getAttribute("num");
25: n=Integer.parseInt(temp);
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause java.lang.NullPointerException
org.apache.jsp.liuyan2_jsp._jspService(liuyan2_jsp.java:76)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet
description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: An exception occurred processing JSP page /liuyan2.jsp at line 2219: temp1=request.getParameter("txttit");
20: temp2=request.getParameter("txtaut");
21: temp3=request.getParameter("txtart");
22: n=temp1.length()*temp2.length()*temp3.length();
23: if(n!=0){
24: temp=(String)application.getAttribute("num");
25: n=Integer.parseInt(temp);
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause java.lang.NullPointerException
org.apache.jsp.liuyan2_jsp._jspService(liuyan2_jsp.java:76)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet
try{
temp1=request.getParameter("txttit");
temp2=request.getParameter("txtaut");
temp3=request.getParameter("txtart");
}catch(Exception e){
//
}
空指针异常,请检查每个变量是否为null
说明你这个jsp的22行中的变量有可能有Null,null.length就会报这个异常
<body bgcolor="#FFFFFF" text="#000000">
<p> </p>
<p align="center"><b><font size="5" color="#FF6633">文物论坛留言板</font></b></p>
<hr size="1">
<%
int n;
String temp=new String();
String temp1=new String();
String temp2=new String();
String temp3=new String();
try{
temp1=request.getParameter("txttit");
temp2=request.getParameter("txtaut");
temp3=request.getParameter("txtart");
}catch(Exception e){
//
}
n=temp1.length()*temp2.length()*temp3.length();
if(n!=0){
temp=(String)application.getAttribute("num");
n=Integer.parseInt(temp);
n=n+1;
temp=temp.valueOf(n);
application.setAttribute("num",temp);
application.setAttribute("tit"+temp,temp1);
application.setAttribute("aut"+temp,temp2);
application.setAttribute("art"+temp,temp3);
%>
<p> </p>
<p align="center">留言成功!</p>
<%
}
else{
%>
<p align="center"><font color="#FF0000">不添加作者、标题和内容,留言失败!
</font></p>
<%
}
%>
<p align="center"><a href="liuyan1.jsp">返回首页</a> </p>
</body>
</html>
n=
temp1 == null ? 0 : temp1.length() +
temp2 == null ? 0 : temp2.length() +
temp3 == null ? 0 : temp3.length()
String temp2=new String();
String temp3=new String();
temp1=request.getParameter("txttit");
temp2=request.getParameter("txtaut");
temp3=request.getParameter("txtart"); 这种写法。上面的temp1-temp3的new String都被冲掉了
String temp1=request.getParameter("txttit");
String temp2=request.getParameter("txtaut");
String temp3=request.getParameter("txtart");这里try catch 不要你来的真准,我正准备下线
org.apache.jasper.JasperException: Unable to compile class for JSP: An error occurred at line: 18 in the jsp file: /liuyan2.jsp
Syntax error, insert ";" to complete Statement
15: String temp1=request.getParameter("txttit");
16: String temp2=request.getParameter("txtaut");
17: String temp3=request.getParameter("txtart");
18: n=temp1 == null ? 0 : temp1.length() + temp2 == null ? 0 : temp2.length() + temp3 == null ? 0 : temp3.length()
19: if(n!=0){
20: temp=(String)application.getAttribute("num");
21: n=Integer.parseInt(temp);
An error occurred at line: 20 in the jsp file: /liuyan2.jsp
temp cannot be resolved
17: String temp3=request.getParameter("txtart");
18: n=temp1 == null ? 0 : temp1.length() + temp2 == null ? 0 : temp2.length() + temp3 == null ? 0 : temp3.length()
19: if(n!=0){
20: temp=(String)application.getAttribute("num");
21: n=Integer.parseInt(temp);
22: n=n+1;
23: temp=temp.valueOf(n);
An error occurred at line: 21 in the jsp file: /liuyan2.jsp
temp cannot be resolved
18: n=temp1 == null ? 0 : temp1.length() + temp2 == null ? 0 : temp2.length() + temp3 == null ? 0 : temp3.length()
19: if(n!=0){
20: temp=(String)application.getAttribute("num");
21: n=Integer.parseInt(temp);
22: n=n+1;
23: temp=temp.valueOf(n);
24:
An error occurred at line: 23 in the jsp file: /liuyan2.jsp
temp cannot be resolved
20: temp=(String)application.getAttribute("num");
21: n=Integer.parseInt(temp);
22: n=n+1;
23: temp=temp.valueOf(n);
24:
25: application.setAttribute("tit"+temp,temp1);
26: application.setAttribute("aut"+temp,temp2);
An error occurred at line: 23 in the jsp file: /liuyan2.jsp
temp cannot be resolved
20: temp=(String)application.getAttribute("num");
21: n=Integer.parseInt(temp);
22: n=n+1;
23: temp=temp.valueOf(n);
24:
25: application.setAttribute("tit"+temp,temp1);
26: application.setAttribute("aut"+temp,temp2);
An error occurred at line: 25 in the jsp file: /liuyan2.jsp
temp cannot be resolved
22: n=n+1;
23: temp=temp.valueOf(n);
24:
25: application.setAttribute("tit"+temp,temp1);
26: application.setAttribute("aut"+temp,temp2);
27: application.setAttribute("art"+temp,temp3);
28: %>
An error occurred at line: 26 in the jsp file: /liuyan2.jsp
temp cannot be resolved
23: temp=temp.valueOf(n);
24:
25: application.setAttribute("tit"+temp,temp1);
26: application.setAttribute("aut"+temp,temp2);
27: application.setAttribute("art"+temp,temp3);
28: %>
29: <p> </p>
代码:
<body bgcolor="#FFFFFF" text="#000000">
<p> </p>
<p align="center"><b><font size="5" color="#FF6633">文物论坛留言板</font></b></p>
<hr size="1">
<%
int n ;
String temp1=request.getParameter("txttit");
String temp2=request.getParameter("txtaut");
String temp3=request.getParameter("txtart");
n=temp1 == null ? 0 : temp1.length() + temp2 == null ? 0 : temp2.length() + temp3 == null ? 0 : temp3.length()
if(n!=0){
temp=(String)application.getAttribute("num");
n=Integer.parseInt(temp);
n=n+1;
temp=temp.valueOf(n);
application.setAttribute("num",temp);
application.setAttribute("tit"+temp,temp1);
application.setAttribute("aut"+temp,temp2);
application.setAttribute("art"+temp,temp3);
%>
<p> </p>
<p align="center">留言成功!</p>
<%
}
else{
%>
<p align="center"><font color="#FF0000">不添加作者、标题和内容,留言失败!
</font></p>
<%
}
%>
<p align="center"><a href="liuyan1.jsp">返回首页</a> </p>
</body>
</html>
分号。
temp2=request.getParameter("txtaut");
temp3=request.getParameter("txtart"); temp1==null?"":temp1;
temp2==null?"":temp2;
temp3==null?"":temp3; n=temp1.length()*temp2.length()*temp3.length();
这样就可以了,至少不会报错。