Today, I needed to remove a property from a JCR node. Somewhat surprising, I haven’t actually had to do that before.
First, I checked out the Node API for delProperty(key), or something along those lines. Nothing. Annoying.
Next, I thought maybe I’d be able to get the result that I wanted by setting the property value to null.
I tried myNode.setProperty("foo", null); and it didn’t work. I got a Runtime Exception with the message
The method setProperty(String, Value) is ambiguous for the type Node
Looking closer at the API docs set me straight
Passing a null as the second parameter removes the property. It is equivalent to calling remove on the Property object itself. For example,
N.setProperty("P", (Value)null)would remove property called “P” of the node in N.
Which, upon reflection, makes sense. There are several different versions of setProperty() for storing different kinds of values and Java can’t figure out which method signature applies when it gets null for the value argument.
I added in an explicit cast and everything worked fine. Upon reflection, though, I might end up using the remove() version next time. I think myNode.getProperty("foo").remove(); might be a bit more transparent for readers.