as we "No keyword should be used as an Identifier in java". But there will be some words like asser or enum or any other which have been added as keyword in version 1.4, 1.5 resp. So if any older version code is used to compile with new javac, what happens if that code contains these words as an identifier?
Are there exists an simple AMPQ server/broker implementation written in Java?
I need it only for local integration tests, starting it from ant/maven, and i don't need any features like a clustering, persistence, performance and so on. Just a fake RabbitMQ-like instance, without installation (just as a dependency at maven pom) and configuration.
Java's jar file format builds off of the zip file format, and supports compression of the class files inside it. When and how does the JVM decide which class files to uncompress and pull out of the jars on its classpath? Is the process dynamic and done at runtime as classes are needed, or are they all uncompressed up front before the program actually runs?
I need to implement a cache solution in java for a cluster of 9 servers with web applications. I saw apache JCS, seems old, do you know another open source solution ?
thanks
Which CMS are you using in Java and what is your experience with it (in terms of extensibility, usage comfort, framework API, memory usage, performance etc.). I am looking for suggestions.
I have a java primitive type at hand:
Class c = int.class; // or long.class, or boolean.class
I'd like to get a 'default value' for this class - specifically the value is assigned to fields of this type if they are not initialized. E.g., '0' for a number, 'false' for a boolean.
Is there a generic way to do this? I tried
c.newInstance()
But I'm getting an InstantiationException, and not a default instance.
When I use the annotation:
@XmlRootElement(name="RootElement", namespace="namespace")
class RootElement {
to create xml file from java, it creates the root element as:
<ns2:RootElement xmlns:ns2="namespace">
but I wanted to create without the "ns2", like:
<RootElement xmlns="namespace">
Any idea how to fix it?
Reletad link (example I used to create the xml):
http://www.java2s.com/Code/JavaAPI/javax.xml.bind.annotation/XmlRootElementname.htm
hi,
when I write a new text file in Java, I get these characters at the beginning of the file:
¨Ìt
This is the code:
public static void writeMAP(String filename, Object object) throws IOException {
ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(filename));
oos.writeObject(object);
oos.close();
}
thanks
I am basically a web application developer, never in my career got a chance of trying out this.. can someone explain the whys and the wherefores for using Native code in java? Thanks a Ton in advance!
What would be the least-slow thread-safe mechanism for controlling multiple accesses to a collection in Java?
I am adding objects to the top of a collection and i am very unsure what would be the best performing collection. Would it be a vector or a queue? I originally thought an ArrayList would be fast but i ran some experiments and it was very slow.
EDIT: In my insertion testing a Vector delared using volatile seems to be the fastest?
I am trying to code a game following instructions contained in an OU TMA document which read:
In the constructor, write code to assign a new instance of Random to ran which you should create using the Random class's zero argument constructor
Will this code work?
Random ran = new Random(0) ;
I am a relative newbie to Java, and I don't understand exactly what the instructions mean
As I remember there is a magic command line option in Java that turn on writing of operations that are currently executed to console. The output was looked like byte code. I do not mean -verbose, because it prints only class loading, while this option outputs information like memory allocation etc.
Is there any framework, whick allows to mock concrete classes, not only interfaces in java 1.4? I have third party code with a singleton class, where I wanna change one function, without touching orignal code. Is it possible?
To learn from good examples, what are the best open source Google App Engine applications out there?
I don't care if it is Java or Python based.
Please one app per answer. Feel free to add a link to the live app (if there is) and to the project page.
I anticipate using some images in my Java application. These images will be drawn onto my JPanel using g.drawImage(). The JPanel is resizable and the images should scale as the JPanel increases/decreases in size
Two questions:
What image format is best for this type of desired scalable image? For instance, in this application, an image of size 100x100 may be scaled into an image of size 30x30 or 10x10 or 300x300.
How can I write code to do this scaling?
I have a hexadecimal string "41464353". I want to convert it into bytes. I know the value of this hex string in byte will be "65706783". I want this as answer. Please give me a program for this in Java.
Hi,
I have an application that passes in java.util.Date. I want to check whether this date is within a specified time of day (e.g. between 10:30 & 11:30), I don't care about the date, just the time of day.
Can anyone show me a simple way to do this?
Thanks
i dont understand why c# is so popular. if it's only good on windows, where as c++ and java work on any system, why is it that c# is so popular? is it because it's accessible to more people since it's easier to use?
c# is the top tag in stackoverflow btw.