How to check if JSON is valid in Java with GSON?

I have method that have to check if JSON is valid, found on How to check whether a given string is valid JSON in Java but it doesn't work. public static boolean isJson(String Json) { Gson gson = new Gson(); try { gson.fromJson(Json, Object.class); re

recursive to iterative (java)

as a beginner in programming I am trying to convert the following recursive method to an iterative one but I just don't get the hang of it. The method or function has a binary tree like recursion and I would like to use an array for the iterative sol

Validation of user input

I have written this piece of code below and I was wondering if it is possible to validate the code entry for "playername". I need to be able to check to see if anything has been entered into this string by the user and I was wondering if it is p

Why is my QueryParam bad?

Disclaimer : I am not a J2EE developer. But this code works elsewhere, but this one api is going crazy. Code @GET @Path("GetCloseby") @Consumes({ MediaType.TEXT_PLAIN }) @Produces({ MediaType.APPLICATION_JSON }) public CServiceCenters getList(@Q

how to print $ or \\ about things regex

could you explain why 3 and 4 spit error? in 1 and 2 cases, i made a conclusion that escaping syntax need two \ characters like \\ in java. but in 3 and 4 cases, it doesn't work. especially in 4 case, something more weird thing is when i put \\\\, it

Define a string of a variable in the JTable line

I'm trying to get the string in one of my rows in my table and put it in my variable a. How can I do that? Here's my code: int row = tb_add.getSelectedRow(); DefaultTableModel model = (DefaultTableModel)tb_add.getModel(); String a; a.setText(model.ge

One-To-Many Relationships in ORMLite Android

How do I implement one-many relationship in ORMLite Android? please find the example public class A { private String name; @DatabaseField (foreign = true, foreignAutoRefresh = true, columnName = "A") private B b; @DatabaseField(columnName = &quo

Converting a string to an object Date

I am reading date values from a file in which i am reading it as string object. The date values varies in many format for example sew below: 01-Mar-2012 01/12/2012 01-12-2012 01.12.2012 01.Mar.2012 07/01/2008 12:00:00 07/01/2008 12:00:00 AM What ever

Unmarshalling with multiple namespaces

So, lets say I have this xml with several namespaces. <Envelope xmlns:pdi="http://www.mypage.com/schemas/pdi" xmlns:ib="http://www.mypage.com/schemas/ib" xmlns="http://www.mypage.com/schemas/envelope"> <Product> &

Verify the accuracy of the encryption key in JAVA

I'm using BouncyCastle to encrypt/decrypt some files using AES and PKCS5 padding in CBC mode : Cipher c = Cipher.getInstance("AES/CBC/PKCS5Padding", "BC"); Now two questions: How can I check that the provided key for decrypting data is

Creating regular expressions for Android

I am trying to make a regular expression but i am newbie in it. And it seems Like i am failing again and again in this.. Kindly if anyone can help me Basically what i want an expression that tests for the following, 1- Something that starts with abc

Changing the size of cell comments in Apache POI

I use the following java code to successfully generate cell comments in Apache POI public static void setComment(String text, Cell cell) { final Map<Sheet, HSSFPatriarch> drawingPatriarches = new HashMap<Sheet, HSSFPatriarch>(); CreationHelper

Google Plugin for Eclipse does not work

wow.. some of my dreams just got true :) Great Tools! Still I've got a problem with it. I've got a pretty fresh install of eclipse 4.2 + Android Development Tools 20 + Google App Engine Tools for Android 3.0.1 + Google Plugin for Eclipse 4.2 3.0.1 Wh

Stitch together images with exact overlaps (pixel to pixel)

I have a bunch of images in a folder that are effectively just pieces of one image that was broken into overlapping parts. How can I quickly and programmatically recombine these images to create the original image? I would prefer a solution that uses

Error executing .class files

I wonder why the Game.class wont start. Here's he problem I got: java.lang.NoClassDefFoundError: Game (wrong name: game/Game)` at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.

How to populate the drop-down menu in Spring MVC

I have been trying to find out how to populate a dropdown box in Spring MVC. There are a few threads out there on this subject but none of them that I have found have helped me so I'm hoping someone here can help me out. Here is my controller: @Contr

Assembling a java project with Maven

my question has 3 parts, short, long and additional. I will start with the short one: Are there any good tutorial/example how to assemble some sort of typical (for example apache like assembly?) I mean tutorial that would address how to develop appli

Create a link to log out for JSP

when a user logins to my application, he submits a form to be processed through the Servlet. The servlet creates a session for the user. How would I create a link so the user can logout? I cannot seem to directly link to a Servlet. How would I delete

Java Generics - Bridge method?

Something called the "bridge method" concept related to Java Generics made me stop at a point and think over it. Btw, I only know that it occurs at the bytecode level and is not available for us to use. But I am eager to know the concept behind

Is the URL checking up or not?

I need to check whether a particular url is up or not. The format of the url is like http://IP:port When I use java.net.URL class then I get java.net.SocketException or java.net.ConnectException. When i ping these IPs, I find them up then why java is

GUID to ByteArray

I just wrote this code to convert a GUID into a byte array. Can anyone shoot any holes in it or suggest something better? public static byte[] getGuidAsByteArray(){ UUID uuid = UUID.randomUUID(); long longOne = uuid.getMostSignificantBits(); long lon

Eclipse IDE's Hello World Cheatsheet Seems to Have an Error

Just a warning: I'm completely new to Java and am trying to teach myself Android programming. I installed the Eclipse IDE today and tried to walk through the first Java Hello World "cheat sheet," and it didn't work! I was really quite surprised.

Regular expression abnormality (Java) - explanation sought

Using Java (1.6) I want to split an input string that has components of a header, then a number of tokens. Tokens conform to this format: a ! char, a space char, then a 2 char token name (from constrained list e.g. C0 or 04) and then 5 digits. I have