Are there regular expression equivalents for searching and modifying tree structures? Concise mini-languages (like perl regex) are what I am looking for. Here is an example that might clarify what I am looking for. An operation that would be possible on the above tree is “move subtree at node 2.1 into t…
Tag: java
Where is allocated variable reference, in stack or in the heap?
I have a question What happend when I declare a variable inside a method, for example. void myMethod() { Ship myShip = new Ship(); } Where is allocated myShip reference, in stack or in the heap ? I think in stack but I’m confused because I was reading in J2ME Game Programming book “Java classes ar…
What is the Java equivalent of C’s printf %g format specifier?
I tried using Formatter.format, but that seems to leave the mantissa on numbers with 0 mantissa, whereas the C version does not. Is there an equivalent of C’s %g format specifier in Java, and if not, is there a way to fake it? My intention is to preserve the mantissa exactly like C’s for compatibi…
How do I copy an object in Java?
Consider the code below: So, I want to copy the dum to dumtwo and change dum without affecting the dumtwo. But the code above is not doing that. When I change something in dum, the same change is happening in dumtwo also. I guess, when I say dumtwo = dum, Java copies the reference only. So, is there any way
Access restriction on class due to restriction on required library rt.jar?
I’m attempting to compile Java 1.4 code that was created by IBM’s WSDL2Java on Java5 without recreating the stubs and saw this error in Eclipse. I’m under the assumption that the stubs generated should just compile as long as the runtime jars are available (they are). Access restriction: The…
How to make a new List in Java
We create a Set as: How do we create a List in Java? Answer or with generics (Java 7 or later) or with generics (Old java versions)
Command line progress bar in Java
I have a Java program running in command line mode. I would like to display a progress bar, showing the percentage of job done. The same kind of progress bar you would see using wget under unix. Is this possible? Answer I have implemented this sort of thing before. Its not so much about java, but what charact…
How to read an external properties file in Maven
Does anyone know how to read a x.properties file in Maven. I know there are ways to use resource filtering to read a properties file and set values from that, but I want a way in my pom.xml like: There was some discussion about this: Maven External Properties Answer Try the Properties Maven Plugin
java.util.Date to XMLGregorianCalendar
Isn’t there a convenient way of getting from a java.util.Date to a XMLGregorianCalendar? Answer I should like to take a step back and a modern look at this 10 years old question. The classes mentioned, Date and XMLGregorianCalendar, are old now. I challenge the use of them and offer alternatives. Date w…
Should Exceptions be placed in a separate package?
I am taking on a project where all the Exceptions have been placed in a separate package com.myco.myproj.exceptions. Is this good practice? Answer I would expect the exceptions for a package to exist within that package. e.g. would contain pricing models and related exceptions. Anything else seems a bit count…