public class register extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String uname=request.getParameter("Uname");
String uemail=request.getParameter("Uemail");
String upass=request.getParameter("Upass");
System.out.println(uname+" "+uemail+" "+upass);
Connection connection=ConnectionProvider.getConn();
try {
java.sql.PreparedStatement pq=connection.prepareStatement("insert into login values(?,?,?)");
pq.setString(1,uname);
pq.setString(2,uemail);
pq.setString(3,upass);
int i=pq.executeUpdate();
if(i>0) {
response.getWriter().println("Data Inserted");
}
else {
response.getWriter().println("No Data Inserted");
}
}
catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
我正在编写此代码以将值输入到数据库中,但是当我填写表单并单击“提交”时,它将在此行显示“NullPointerException”: java.sql.PreparedStatement pq=connection.prepareStatement("插入登录值(?,?,?)"); 此代码中的错误的实际原因是什么?