Java exception java.lang.reflect.InvocationTargetException with null pointer exception

Java.lang.reflect.InvocationTargetException and with null pointer exceptions at the same time,

This error is derived from the implementation of the user automatic login function: Login interface, when entered user name and password, not checked automatic login button, the results in Userservlet implementation method, as long as there is getparameter ("Autologin");

Analysis: The use of filters to implement the GetParameter method packaging design enhancements, not adding null pointer anomaly judgment. So when using a custom getparameter in the Servlet method, when the user does not check the auto-login button, the get is empty. So this error is reported.

Solution: When the GetParameter method packaging design to enhance the function, add to the parameters obtained null pointer judgment. or throw out an exception. A large exception catch (Exception e) {}

class Myrequest extends httpservletrequestwrapper { Public Myrequest (HttpServletRequest request) { Super (request); } @Override Public String GetParameter (string name) { String word = Super. GetParameter (name); Try { if (Word = = null) { return null; } Word = new String (word.getbytes ("iso-8859-1"), "UTF-8"); } catch (Unsupportedencodingexception e) { E.printstacktrace (); } catch (Exception e) { E.printstacktrace (); } return word; }}

Exception code:

Java exception java.lang.reflect.InvocationTargetException with null pointer exception