what is the use of concurrent hash map in java? where we have to use this? what are the comforts in it? help please. how it works? sample codes are easy to understandable..
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
When I do System.out.println(map) in Java, I get a nice output in stdout. How can I obtain this same string representation of a Map in a variable without meddling with standard output? Something like String mapAsString = Collections.toString(map)?
I have a java.sql.ResultSet object containg data from a query that was run.
How do I refresh the data in the ResultSet to reflect the current data in the database?
Thanks!
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?
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
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?
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?
Is there a way to access the Java Plug-in Control Panel programatically? Or at least find the places in the Windows File System where the information backing that control panel is stored?
Is it possible to reliably determine the compilation time stamp of a given class for both java applications running locally and as applets and/or JNLP webapps ?
as we know java is not pure oop because primitive type.
is there any else cause for it
please share..
think static variable and multiple inheritence also have same resp...
Pleas correct me..
I read a lot of blogs and see people all the time talking about bad things in the java programming language; a lot of them are about annotations and generics that were added to the language in 1.5 release. What are the things in the language or the API that you don't like or would design differently?
I am new to regular expressions. I want to use java's replaceAll() function to replace any CSS comments in a string.
Basically I want to use regex to search for anything that is surrounded by "/*" and "*/" and replace it with "".
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.
Possible Duplicate:
The Definitive C++ Book Guide and List
What is the best text book a beginner (non-CS major) can buy to master C++? And for Java?
Thanks
I'm writing a program that uses scp to copy files in a bigger java program. As it stands now, the program freezes up while the scp is copying the file, which can take a few minutes, so I'd like to be able to display the progress of the scp or at the very least get the terminal window with the scp progress to show up! Any suggestions?
I'm taking user input from System.in using a java.util.Scanner. I need to validate the input for things like:
It must be a non-negative number
It must be an alphabetical letter
...etc
What's the best way to do this?
Hi,
Does anyone know a library to compare addresses in Java ?
Something that would give equality on addresses, written in different ways.
For example, it should recognize that
"22 Acacia Avenue" and "22 acacia av."
is the same address.
Of course, this can escalate a lot, that's why i'm asking.
Thanks in advance.
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.