Servlets :: Unable To Run Listener Class Also ContextListener Is Initialized
Mar 8, 2014
again i am facing problem i am able to run Listener class also the ContextListener is initialised but it is giving me error on Tomcat 6.0 command prompt
Here is my Listener Class Sample.java i am able to compile the code but it is giving java.lang.nullpointer exception at runtime on Tomcat.exe Is there is problem in my code
I have data base connection which i have configured via a listener class i configured properly in DD but still i am not able to deploy the project and server log show that startL.java listener class was not found why is this so as config is proper with the name
how it is decided which class will implement a session listener interface? Which class will implement HttpSessionListener? Which one will implement HttpSessionActivationListener, HttpSessionBindingListener or HttpSessionAttributeListener?
I am stuck with my application. I have jsp, servlet application with jasper report server. When I run the application through eclipse, everything works perfectly. But When I try to run it in Tomcat (without eclipse) it gives me the "Unable to resolve the class file " error. I tried all the solutions I got through the google, but still I am unable to come over it.
class Super { static String ID = "QBANK"; } class Sub extends Super{ static { System.out.print("In Sub"); } } public class Test{ public static void main(String[] args){ System.out.println(Sub.ID); } }
According to me output should be "QBANK" In Sub...BECAUSE sub default constructor will call super() constructor.. below is the definition in jls which i am unable to understand ....
A class or interface type T will be initialized at its first active use, which occurs if:
T is a class and a method actually declared in T (rather than inherited from a superclass) is invoked.
T is a class and a constructor for class T is invoked, or T1 is an array with element type T, and an array of type T1 is created.
A non-constant field declared in T (rather than inherited from a superclass or superinterface) is used or assigned. A constant field is one that is (explicitly or implicitly) both final and static, and that is initialized with the value of a compile-time constant expression . Java specifies that a reference to a constant field must be resolved at compile time to a copy of the compile-time constant value, so uses of such a field are never active uses.
All other uses of a type are passive. A reference to a field is an active use of only the class or interface that actually declares it, even though it might be referred to through the name of a subclass, a subinterface, or a class that implements an interface.
I was wondering if there is a way to be certain that listeners would be invoked in any specific order? Note that I am referring to servlet specification version prior to version 3.0. As per version 3.0, the ordering followed would be the one in web.xml (Reference: Servlet specification 3.0: Section 8.2.3). This section also says that prior to 3.0 the order of invocation is random.
Possible duplicate entry but reply does not match the specification text : URL...
I am using Jframe to do keylistener to detect what key i type. so example when i type A it will return A and so on for other key. But what i really want is using textarea in jsp and have this similar or same code in servlet. Below are the code in JFrame
1. I am trying to use the getSource method in my inner class, in order to set the JPasswordField within an Inner Listener Class. This is a 4 integer password, setup by my for statement in the loop. I know what I want the program to do, but I don't know the correct language to use. I want the user to press one of the keys (0-9), that value be stored in JPassword (at least I think that is how it works) and for it to display the "*" in the Field---I want this to loop 4x. How do I use the getSource() to do this.
Also, I believe I need to use the set and get methods for the password entered into the JPassField, is that correct? The inner class is not recognizing my the object password that represents the JPasswordField.
2. In my second Inner Listener Class, clearButton, I set the event.getSource method to reset the JPasswordField to " ", when the clear button is pressed. Again, the problem is that the inner class does not recognize password. Why is this the case, since it is still a part of the parent class Atm?
public class Atm extends JFrame { Atm(){ super("ATM"); int i = 0; //Create Panels For ATM JPanel buttonPanel1 = new JPanel(); //To Contain Digits 1-9 buttonPanel1.setLayout(new GridLayout(4, 3));
I have two different classes called Login (in the package View) and RegButtonListener (in the package Controller). I want to use the MVC pattern.
Login creates a GUI for login. I used NetBeans GUI Builder to create it.
In the class RegButtonListener there is the code for the click of the buttons, then various listeners of the GUI.
Now I want to close the login frame at the click of a button so I want to use the dispose() method.
If I had all the code (GUI code and code of the listener) in the same file, close the frame would be easy enough to do because this.dispose(). But in my case I have two different classes.
I also have a second problem.
In Login class (in the packege View) I have included the line :
However, Netbeans tells me an error "package regButton does not exist. <identifier> expected". Why does he consider regButton a package? How can I fix these two problems?
How do I do then?
Below is the code of the two classes.
Login class. public class Login extends javax.swing.JFrame { /** Creates new form Login */ public Login() { initComponents();
i am using eclipse kepler and tomcat 7 with the below code to get a response from the browser. i get no errors on my code and i organize my imports but when i run the code i get an http 404 error. i restart the server and it goes into the whole motion telling me that "Tomcat v7.0 Server at localhost started and is synchonized" i refresh it and i still get the error.
When I am invoking a servlet class file from my HTML file instead of displaying output in my browser it is downloading my output as a file..Why it is?..
I have the file in my project sitemap.xml, which i am trying to write via XMLStreamWriter. My code gets successfully executed as i can see the logs. But my sitemap.xml file keeps blank. Why nothing is getting write in my sitemap.xml file. Below is my servlet code.
I wrote a code to download a zip file in jsp, but it is not working as expected, when i execute this following program i am able to download file with "download_all.jsp" name, but now original download file (/tmp/Download_All/1244687508907.Zip). The download_all.jsp is my jsp name which is having the following code. Here is the code snippet:
try { String filename = "/tmp/Download_All/1244687508907.Zip"; if(request.getParameter("filepath")!=null){ filename=request.getParameter("filepath"); } // set the http content type to "APPLICATION/OCTET-STREAM response.setContentType("APPLICATION/OCTET-STREAM");
I am trying to display rows from my database from servlet by passing it to a JSP, but nothing is displayed. I checked the syntax and even the source of the page shows that it gets the data but the rows are not displayed!
Regarding the lifecycle of servlet , in headfirst servlet i can find :
You normally will NOT override the service() method, so the one from HttpServlet will run. The service() method figures out which HTTP method (GET, POST, etc.) is in the request, and invokes the matching doGet() or doPost() method. The doGet() and doPost() inside HttpServlet don’t do anything, so you have to override one or both. This thread dies (or is put back in a Container-managed pool) when service() completes.
How can I call the doGet method of the subclass from the superclass. i am not getting this .
i am trying to work through the Murach's Java Servlets and JSP book. I am stuck however. I keep getting a HTTP Status 500 - Unable to compile class for JSP.
I am using Eclipse Kepler, JDK 1.7, and Tomcat v7.0 server.
Its a fairly simple program that takes in user information, first name, last name, and an email and processes the information, saving the data to a text file.
------------------------------------------------ I have two Java classes: User and UserIO -------------------------------------------------
//User.java package business; public class User { private String firstName; private String lastName; private String emailAddress; public User(String firstName, String lastName, String emailAddress){
below is my code and this exception was thrown in another page so I created a new page and only imported just a single package still its throwing an exception? Any reasons why?
I am trying to create a program for class the uses two dimensional arrays. I am stuck on the second step that states Use two parallel arrays. One is a two-dimensional array -- a row of this array will hold six values in this order: [0] number of hours worked, [1] hourly pay rate, [2] gross pay, [3] net pay, [4] federal withholding, and [5] state withholding.
This is what I have so far:
Java Code:
double [][] data = new double [30][6]; String [] names = new String [30]; String str = null; String detail = null; int n = input(data, names, inputFile); mh_sh_highlight_all('java'); (there's more but i don't believe it pertains to this question)
My question is how would I create this array. Or, is that right above? I've searched online and in my book and I just don't understand.
I've been trying to pull data from another class file "Calculations.java" and have it be displayed in a TextField in "DataAnalyzerGUI.java". Here is how the hierarchy is broken down for my assignment:
I'm trying to load a class file into Oracle using loadjava and I get the following error:
ORA-29552: verification warning: java.lang.UnsupportedClassVersionError: helloworld (Unsupported major.minor version 51.0)
Presumably this is related to an inconsistency between the jdk that I used to compile helloworld and the Oracle JVM? Or something like that?
My JAVA_HOME is C:Program Files (x86)Javajre7bin My javac version used to compile the code is javac 1.7.0_15 java -version is "1.7.0_15" When I do a find on java.exe in the oracle installation directory (I'm running 11.2) I get
