求帮忙 为什么传递的pnum是空的 导致空指针异常?!
jsp代码:<a onclick="if(confirm('确定删除')) return true; else return false;" href="ProductDelete?ddh=<%=ddb.getPnum()%>" class="xhx"><font color="#0033CC">
删除</font></a></td>servlet代码:
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//super.doGet(request, response);
doPost(request, response);
} /**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//super.doPost(request, response);
request.setCharacterEncoding("gbk");
ProductService co = new ProductService();
String pnum="";
if(!request.getParameter("pnum").equals("")){
pnum = (String)request.getParameter("pnum");
pnum= new String(pnum.getBytes("ISO-8859-1"),"gbk");
System.out.println(pnum);
co.deleteProduct(pnum);
response.sendRedirect("ProductViewZZJ");
} }j2eeservlet异常指针
jsp代码:<a onclick="if(confirm('确定删除')) return true; else return false;" href="ProductDelete?ddh=<%=ddb.getPnum()%>" class="xhx"><font color="#0033CC">
删除</font></a></td>servlet代码:
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//super.doGet(request, response);
doPost(request, response);
} /**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//super.doPost(request, response);
request.setCharacterEncoding("gbk");
ProductService co = new ProductService();
String pnum="";
if(!request.getParameter("pnum").equals("")){
pnum = (String)request.getParameter("pnum");
pnum= new String(pnum.getBytes("ISO-8859-1"),"gbk");
System.out.println(pnum);
co.deleteProduct(pnum);
response.sendRedirect("ProductViewZZJ");
} }j2eeservlet异常指针
解决方案 »
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href="ProductDelete?ddh=<%=ddb.getPnum()%>"
request.getParameter("pnum")
href="ProductDelete?ddh=<%=ddb.getPnum()%>"你这里不是把pnum的值赋给ddh了吗?参数名是ddh了啊
ProductService co = new ProductService();
String pnum="";
if(!request.getParameter("pnum").equals("")){
pnum = (String)request.getParameter("pnum");
pnum= new String(pnum.getBytes("ISO-8859-1"),"gbk");
System.out.println(pnum);
co.deleteProduct(pnum);
response.sendRedirect("ProductViewZZJ");
}
写错了吧 你传值的阐述是ddh 接收的是pnum 肯定是null