Question

Servlet.service() for servlet test threw exception java.lang.NullPointerException

用户名：s密码：s
七月 01, 2007 3:07:27 上午 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet test threw exception
java.lang.NullPointerException
at myfirstServle.TestRequestServlet.testParameter(TestRequestServlet.java:47)
at myfirstServle.TestRequestServlet.doGet(TestRequestServlet.java:23)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// PrintWriter out=resp.getWriter();
// out.println();

testParameter(req);
}

void testGetNeInfo(HttpServletRequest req){
System.out.println("客户的IP："+req.getRemoteAddr());
System.out.println("contextpath："+req.getContextPath());
System.out.println("客户端口："+req.getRemotePort());
System.out.println("host："+req.getRemoteHost());
System.out.println("contexttype："+req.getContentType());
System.out.println("contextpath："+req.getRemoteUser());

}

void testParameter(HttpServletRequest req){

String name=req.getParameter("uname");
String pwd=req.getParameter("pwd");

System.out.println("用户名："+name+"密码："+pwd);

String[] mobles=req.getParameterValues("moble");

for (String m:mobles) {
System.out.println(m);
}

}

Answer 1

TestRequestServlet.java:47这个页面第47行，空指针异常，对象值为null,还有23行

追问

谢谢，大神！是这样的！！！
不过还有个问题，能不能告诉我，它为什么会执行两次呢？你看执行结果：
用户名：ewr密码：wer
1
用户名：ewr密码：wer
1

追答

那应该就是页面上有问题吧，

追问

好吧，我再看看吧，谢谢了，我还是希望，大神能再说出大概什么地方的问题

追答

页面有ajax吗，要不你把页面也贴过来