Reading a resource from the Classpath in Java

Today I found something that, although very subtle, helped me to get out weird behaviors.

I’m working in a Twitter API written in java and needed to load a configuration file from a package among my source code. So I tried with this.getClass().getResourceAsStream(filename) but wasn’t being able to get it, so I googled some about it and found something very interesting.
The code this.getClass().getResourceAsStream(filename) only looks for a file on the same directory of the .class file. To load a file that’s somewhere within the enrire classpath do this.getClass().getClassLoader().getResourceAsStream(filename).

When you stop a second and think about the first piece of code you see that this behavior is more logic than what you were expecting.

For those who don’t understand how did they do it take a look inside the code from the Class class.
The getResourceAsStream(String) method calls a resolveName(String) method that actually append to the string parameter the path of the class itself. So that’s why you only can load files from the .class directory.

Hopes it can help some one with the same doubts that I had.

Easy currency formatting with javascript

Sometimes you need HTML text fields to format currencies with a fixed number of decimal digits. One thing that isn’t very known, and sorry if it actually is for anyone, but javascript already arrive with a function that do exactly the job for us.

function formatToCurrency(el){
var value = el.value;
el.value = new Number(value).toFixed(2);
}

Then you could trigger this function as the onblur event of your form control this way:

onblur="formatToCurrency(this)"

That’s it, now when you move out your mouse from the control it will automatic format your input.

I know this code is really poor but it satisfy the needs of a lot of users. The code isn’t localized but it isn’t hard to figure out how to do it. Actually what brought me to the toFixed function was my searches on a localized generic number formatting script.