Servlets :: Filter Behavior When Exception Is Thrown
Apr 21, 2014
I just wanna confirm that when a certain processing throws an exception even when said exception happens inside doFilter, any servlet container will never proceed to the next filter right?
throw new RecordNotFoundException("E888", "This is custom message X"); }
My questions are:
Is this the correct way to invoke a jsp when my code throws an exception?Do I need a try catch block to handle the thrown RecordNot Found Exception, if yes how would I navigate to the jsp from the catch block?
I have been working with socket programming. I was trying to develop a two way communication from server to client. The data is being received when sent from server to client but there is a problem when I am sending from client to server.
I am getting an error as "Socket is closed" pointing to the line where I have created a BufferedReader. I have simplified some part of my code to be very specific.
Code attached.
import java.io.*; import java.net.*; import java.util.*; public class Server { public static void main(String args[]) { String id="policeone"; int hashcodeid=0;
[Code] ....
Error::
Receiving string from client: 'java.net.SocketException: Socket is closed at java.net.Socket.getInputStream(Socket.java:872) at Server.main(Server.java:51)
Below is a code of a simple file downloader in java. I want to detect an exception when the connection is broken in the middle of downloading a file. Now, I run the code and in the middle of downloading the file, i turn off my wifi with keyboard wifi off button. Doing this the program hangs forever without throwing any exceptions and without terminating. It seems it blocks forever.why is exception not thrown? Secondly, in the following code you can see this line //con.setReadTimeout(2000); which is currently commented out. Removing the comment and running the program, now if connection breaks in the middle by turning off wifi then it waits for 2 seconds and then if it cannot read then it terminates without throwing exception. So, again in this case why is it just terminating and not throwing any exception?
I am getting the above error and am not sure which direction to proceed. In the class, the only way we have discussed getting user input is by System.in.read. I have searched and apparently found better methods for getting user input, but wanted to stick with what has been presented thus far.
Assignment Directions:
1. Create a new class named “valuemethod”
2. Create a new method named “Main”
3. In Main Write the code that will call the method EnterPay and YearlySal
4. Create a new method named “EnterPay”
5. In the EnterPay method Write the code that asks the user to input their hourly wage. Use the formula to calculate their yearly salary: wage * 2040. Return the yearly salary to the main method
6. In the main method write the code that will display this: “Your yearly salary is:
Java Code:
package valuemethod; public class Valuemethod { public static void main(String[] args) //throws java.io.IOException -- moved to EnterPay
I am attempting to create a very simple game where two squares move around and each can see the other square moving. This is a multi-player game over a TCP network using JavaFX. I am getting an illegal state exception when I call requestFocus(). This is my server:
public class GameServer extends Application { ObjectOutputStream p1out; ObjectOutputStream p2out; int PLAYER1 = 1; int PLAYER2 = 2;
In my cs class, we have to write a program that throws an exception if the user enters a negative number, the program should prompt the user to enter only positive numbers and then let them retype the number. But everytime I throw an exception, my program gets suspended.
What am I doing wrong, or is there no way to continue a program if an exception is thrown? Does the program automatically get suspended when an exception is thrown?
try{ do { N = kb.nextDouble(); if(N<0) { throw new NegativeArraySizeException(); } else j++; } while(j==0); fill.size(N); } catch(NegativeArraySizeException e) { System.out.println("The number you entered must be positive. Please try again."); }
Looking for some simple use cases for servlet filters other than tracking requests ? I was thinking of using a filter to filter out offensive language from entered text. Would that be a good use case ?
I mentioned the url-pattern in web.xml correctly and i also checked whether all the class files are present or not. But I am still getting ResourceNotFoundRException.
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859
I have two classes LightController & Circle. I am trying to create a method to do the following.
1.Grows the diameter of the circle referenced by the receiver's instance variable light, to the argument size.
2. The diameter is incremented in steps of 2, the xPos and yPos are decremented in steps of 1 until the diameter reaches the value given by size.
3. Between each step there is a random colour change. The message delay(anInt) is used to slow down tthe graphical interface, as required.
How can I write the method to do this? I have been fiddling around for ages and just had no luck.
The method is called public void grow(int size) and is in the Light Controller class.
Both classes can be seen below.
import ou.*; import java.util.*; /** * Class LightController * This class uses the Circle class, and the Shapes window to simulate a disco light, that grows and shrinks and changes colour. * */
public class LightController { /* instance variables */ private Circle light; // simulates a circular disco light in the Shapes window private Random randomNumberGenerator;
I have two classes LightController & Circle. I am trying to create a method to do the following.
1. Increase the size of the circle by increments of 2 as created in grow() 2. Once it has reached the size specified to then reduce in size in crements of 2 as created in shrink()
I have got the method to increase the size but once it reaches the specified size it then does not shrink.The method is called public void lightCycle(int sizeIncrease) and is in the Light Controller class.Both classes can be seen below.
import ou.*; import java.util.*; /** * Class LightController * This class uses the Circle class, and the Shapes window * to simulate a disco light, that grows and shrinks and * changes colour.
I have a JTable that is being used to display, and edit data from a database. When the user presses the Enter key on the keyboard I want a carriage return to occur in the cell they are typing in. I do not want the cursor to go to the next row which is the default behavior.
I'm new to machine learning approach. I want to find user behavior profile using one class SVM in java. I d't know how to do it. Finally, we need to provide privacy to each user and their data.
Requirement:
1. Collect the behavior profile for each user. 2. Apply one class SVM.
Basically I'm trying to compute the standard deviation for a set of numbers and I'm using previously know data to compute this. The data I'm working with is here (note all of this is fake as its for an assignment):
Next this is the code that I know is producing the error:
/** * Pass in original data from files, and pass in computed grades as arraylist. this returns all of the standard deviations to be printed */ public static ArrayList calcStandDev(String data1[], ArrayList<Double> grades, ArrayList<Integer> averages) { double standDev = 0; int j = 0; //gets rid of first element in string array, makes processing MUCH easier String[] data = Arrays.copyOfRange(data1, 1, data1.length);
[Code] ....
Look for the line with all the ***'s, it is producing the "java.lang.ClassCastException: java.lang.Double cannot be cast to java.lang.Integer".
The reason I dont undersand why its producing this error is because temp.get(i) should be a integer - averages.get(i) (is type double), I do believe automatic up casting is present here making them both a double then I multiply it by itself producing a double? I dont understand where the casing is occurring. And just incase you want the formula I'm using for standard deviation here it is:
I need to create a simply application that would display the results of two dice thrown five times and the total of those results. This is shown below in the attached file.
The problem is, I have a do-while loop that loops 6 times. Inside the loop, I have 2 random.nextInt(5) that generate random numbers. But how can I output the total? How can I make a variable equal to the sum of the two random numbers if the two random numbers are located inside a do-while loop?
Attached below is also the code I have thus far.
(Attached below is both files: what it needs to look like, and what it currently looks like)
I have two classes (Daughter and Son) that contain some very similar method definitions:
public class Family { public static void main(String[] args) { Daughter d = new Daughter(); Son s = new Son(); d.speak(); s.speak();
[Code] .....
Each of those classes has a "speak" method with two out of three lines being identical. I could move those into a parent class, but I need each of the child classes to continue to exhibit its unique behavior. I'm trying the approach below, which replaces the unique code with a call to a "placeholder" method that must be implemented by each child class:
public class Family { public static void main(String[] args) { Daughter d = new Daughter(); Son s = new Son();
[Code] .....
This works and moves the shared code from two places (the Daughter and Son classes) into one place (the new Mother class, which is now a parent class of Daughter and Son). Something about this feels a bit odd to me, though. It's one thing for a child class to override a parent class's methods to extend or alter their behavior. But, here, I've implemented an abstract method in the parent class to alter what happens when the parent class's method (speak(), in this case) is called, without overriding that parent class method itself.
I have a JSF app and for some reasons i need to refresh the page on browser back button.I tried implementing the solution given in Force JSF to refresh page / view / form when back button is pressed ,the only difference is that my app runs with servlet version 2.5 so i did the mapping in web.xml as below
I implemented the gray scale filter and the convolution filter . If I apply before the grayscale filter convolution and then I can not see the picture, I see pretty much the JPanel that should contain the image. The two filters separately functioning correctly
Code filter grey scale
public BufferedImage greyScale(BufferedImage originalImage) { BufferedImage destImg = new BufferedImage(originalImage.getWidth(), originalImage.getHeight(), BufferedImage.TYPE_INT_ARGB); int alpha, red, green, blue; for (int x = 0; x < originalImage.getWidth(); x++) { for (int y = 0; y < originalImage.getHeight(); y++) { int pixel = originalImage.getRGB(x, y);
I am a newbie in java prgmming using netbeans IDE . I have a code Java Code:
List<String> files = service.getSecureCloudStoragePort().listFiles(); SelectFileDialog dialog = new SelectFileDialog(this.getFrame(),true,files); mh_sh_highlight_all('java');
My files value get as :
[1_car.txt@2, 5_Van.txt@6]
The 2 and 6 refers user id ... I need to show only particular user with his own id.
So need to filter the files value with that id (after @ in raw data) .. How it can do ? any method to filter the data . That data format could not be changed in any way...
I want to use a switch or if/else statement to filter out the data I don't need for the app. This is by no means anything more than a draft because java is easier to work with than android.
I have a situation to load data while JSF page loads. Also have a filter which populates user information from http request.
I was expecting the filter first to populate the user information and in the managed bean get method to verify the user information and get the data (from database). But in this case i see the managed bean get method is invoked before filter populates user information and i get null pointer exception because the user information is null.
I had to work around to get the user information from FacesContext in the managed bean get method because the user information wasn't available. Is there a way to make sure the filter is invoked first?