Servlets :: How To Exchange Data In Different Nodes In Same Cluster
Jul 21, 2014
What is better and easier approach for exchanging data (in my case list of objects) between servlets in different nodes in same cluster? I thought about RMI or just direct url servlet call. But it seems that I'm missing something here.
My problem is the following:
I have to create some kind of diagnostic storage for each cluster member. It will collect all information and errors during application work.
And If I need to check application status I do web request and it will show me that these servers (cluster members) are okay and that node has an issue.
i want to publish data from my application to mobile devices as calendar-events and back.therefore i want to write an application (webservice, servlet,???), which i then can add as a new account in my e.g. android device' calendar.
shortly: my application should simulate an exchange-/activesync-server, since on "all" mobile devices i can add exchange accounts.is/are there any documentation, libraries,
public void add(int d){ listNode l = new listNode (d, null); l.next = first; first= l; } public list Sum2List (list l1, list l2){ //variables int sum;
[Code] .....
But I have a problem in my first listNode where it ll be pointing to null, thus in the sum2List method the program checks the while condition into false and doesn't go through the loop.
TL,DR: observe the nodes just below, that is the data each node in the link list contains. How do I iterate through the entire list to reach the last element (H), so I can add an element right after it?
So I have 4 nodes doubly linked with two dummy nodes for head and tail:
Ok, so since the list only contains 8 elements that are not null, its size is actually 8 correct? So now lets say I have an add method that has
add(E item) and inserts the item at the end of the list. So I can get to the last node with tail.previous(), but then how do I iterate to the end so I can add the item after the last item in the list (H). I guess I don't know how you only access one nodes data when that data is an array with empty spaces.
Here is the entire Node code:
Also, I can't just iterate through the whole thing because I am not supposed to. I am supposed to just find the right node and iterate through that only.how to maneuver around a linked list containing nodes where each node contains an array.
/** * Node class that makes up a DoublingList. Feel free to add methods / * constructors / variables you might find useful in here. */ public class Node<E> {
/** * The node that comes after this one in the list
Write a Java function Sum2List that takes two lists L1 and L2 of the same size and returns list L that contains the sum of data inside the corresponding nodes of lists L1 and L2.
I have some class called sorted to sort the linked list through the nodes of the list. and other class to test this ability, i made object of the sort class called "list1" and insert the values to the linked list.
If i make other object called "list2" and want to merge those two lists by using method merge in sort class. And wrote code of
list1.merge(list2);
How can the merge method in sort class know the values of list1 that called it as this object is created in other class.
I would like to understand how does multipart/form-data works during file upload scenario's, Does it chunks the data from client to server while transferring the files ?
I am able to upload the file to the server, but I am not able to get the value of text1 in the servlet (I am getting null value of text1 in the servlet), I need this textfield in the form to submit some additional information while uploading it to the server.
--> Is enctype="multipart/form-data" option of form doesn't allow other form data to be submited? if it doesn't allow it then what are the other options I have to send this additional textfield to the server.
I need to create a Dog class that represents a dog. Then, there are 2 different methods that in the end will each represent one dog each. Each printout will show the Name, Breed, Age, and Age in Human Years. Right now I'm having trouble trying to move methods in between each class. Here's the first class.
import java.util.Scanner; public class Dog { //no main method static Scanner input = new Scanner(System.in); //writeObject method public static void writeObject(String name, String breed, int age) { System.out.println("Enter the dog's name, breed, and age: ");
I am working through a project in which I am supposed to change dollars into yen with the use of different deposits. I will post the code below that I have been working on.
import java.util.*; public class DollartoYen { public static final int MAX_DEPOSITS = 100; public static final float DOLLAR_TO_YEN = 0.098f; // read number of Dollars in each account from the keyboard void readDollars(float[] dollars, int count ) {
I need to implement Oauth2 with facebook to get authencation. I tried to write a servlet with the method Service, and i got the code thah i have to use in a second request.
Now i need to send a request at this URL :
1) [URL] .....
and wait for a responce with an URL that have the access_token to use with facebook
2) [URL] ....
Is it Possible in a single Servlet after i receive the "code" to send a second request to the URL in 1 and get the response with URL in 2 to retrieve the access_token?? if yes....how??
I have an html form with 200 input fields of type text. The first input field contains the name of a book author and the remaining 199 fields hold each a title of a book that he or she has written. I also have a servlet that processes the form data and sends it to a file. The entered data is restricted to a combination of the characters "a...z A...Z". how do i go about with creating my html page. The input fields are just too many, how to retrieve the 200 values in servlet.
<html> <head> <script> var k; function testField(Expression){ k=1; var str1="abcdefghijklmnopqrstuvwxyz "; var sor=Expression;
I have a basic HTML calculator that asks the user to input 2 integers and select from a dropdown their desired math operation:
The servlet will process the calculation and counts how many times a certain operation has been used:
The counter for Multiplication has incremented accordingly.
HTML: <form action = "processcalc.html" method = "post"> <table> <tr> <td>First Operand:</td> <td><input type = "text" name = "firstOperand" required></td>
[Code] ....
Question: However, when I press "Go Back" and process a new computation, all counters reset to 0. Is there a way without using HttpSession to persist the counter values? (It has not been taught to us, so we are not allowed to use it yet.)
For example, going back and having below input... First Operand: 4 Operator: + Second Operand: 5
...will result to... Addition: 1 Subtraction: 0 Multiplication: 1 (counter from previous computation maintained) Division: 0
I can insert data to table by using JSP Scriptlet easily but I have a hard time with servlet.
public class UsertToDatabase() { public boolean inserUser(String name, String email, String pwd) throws SQLException { PreparedStatement pstmt = null; boolean flag = false; System.out.println("start"); openConn(); System.out.println("start_1"); if(conn == null) {
[code]....
I am positive that the above code function fine. The problem is whenever I call UserToDB() class inside the servlet, and I got this error: java.lang.ClassNotFoundException: org.postgresql.
Driver which mean that my conn (connection) is not connected to the database but I have ensure to do so by calling openConn() before start the transaction.
Now I want to store those username and age(in .html) somewhere and I want those information in welcome.jsp. Now, I'm storing all those in session itself(In doGet method(servlet)).
2 Doubt) Also, when I get the session in servlet HttpSession session = request.getSession(); line No. 27. The session value is org. apache. catalina. session. StandardSessionFacade@69a8bf4f...I'm expecting that session is to be empty. Because, I dint store anything until that line.
I'm new to json and the web. My purpose is to use json data from a server and parse it and show meaningful data to the user. I am aware of json parsing, so no sweat there. However, I would like to know how json data is sent to the front end after which it can be parsed.
Usually in my json parsing examples, I have a variable like var data = ]OR I do a getJSON on a data.json file which I have stored in the project folder. However, I want this data to come real time from a servlet. How to go about this?
So, basically my question is, how do I send real time json data from a servlet backend, say some records which I have extracted from the database using jdbc?
I have a very simple HTML form with a textField for a name, and add button to add the name to a MySQL database, and a sort button to sort the names in the database and display them. I almost have it working, however when I hit the "sort" button; I get the message that appears after a user clicks the add button along with the sorted list of names. It looks like this:
Please go back and add a name or sort. Bill Jones David G Debbie Downer Jane Doe Joe Smith John Doe Mike Jones Paul Smith Susan Jones
What I have to change on my code to make just the list show up by itself when the user clicks sort?
Is it possible to get the list/ values in html/jsp from servlet?
I have a table inside an html/jsp page and when the user clicks a button I need to refresh the whole page with some additional text message.
Currently what I am doing is that I am using a java bean for the jsp page that contains a list of values inside the table then store it in session but I think there is a better way without storing it in session.
I tried using request.getParameter() but it only returns string.
i am newbie to servlet and m working on a project like online shopping. I have list of data items in my database and i am able to fetch and display the data from database but i want to know that how can i store these data items in ServletContext so that i can use use it frequently in other pages.
