Categories
Development Java

Java: Converting long to double

While Integers has to be parsed from a String, doubles can simply be casted:

String bar = "9.99";
Double foo = (double)bar;
Categories
Java

EXT GWT: Adding onClick to Labels

I had a issue where i needed to add a click handler for labels in EXT GWT, the solution i came up with was as follows

theLabel.addListener(Events.OnClick, new Listener() {
@Override
public void handleEvent(BaseEvent be) {
    // TODO Auto-generated method stub
}});

 

Categories
Java

Guice: java.lang.IllegalStateException: No SessionHandler or SessionManager

One reason for this error would be that you should inject the session object directly, not via constructor:

So instead of:

@Singleton
public class Foo {

@Inject public Foo(HttpServletSession s) {
this.session = s  }
}

do this:

@Singleton
public class Foo{

@Inject Provider<HttpServletSession> session;

}

And it should work much better 🙂

Categories
Development Java

class Foo is public, should be declared in a file named Foo.java

When working with Java you might encounter this error. The reason for this is that you have tried to declare a public class in a file with a different name. Each java file can only contain one public java class, which is named the same as the java file itself. If you need another class inside your other class you should looking into private inner classes.

Categories
Development Java Linux Red Hat Software

jpackages error: Missing Dependency: /usr/bin/rebuild-security-providers

Jpackages on Red Hat has a nifty bug that causes dependency errors.

Luckily, somebody has created a fix as a rpm package 🙂

wget http://plone.lucidsolutions.co.nz/linux/centos/images/jpackage-utils-compat-el5-0.0.1-1.noarch.rpm
rpm -ivh jpackage-utils-compat-el5-0.0.1-1.noarch.rpm

And then jpackages works.