Keep Coding

I am trying to create a view plugin in the Eclipse environment. I need to call another class, but when I use as usual Class cl=new Class(); it does not work:
private void makeActions() {
action1 = new Action() {
public void run() {
showMessage("Action 1 executed");
DataInterfc interface=new DataInterfc();
}
};
action1.setText("Informations");
action1.setToolTipText("Action 1 tooltip");
action1.setImageDescriptor(PlatformUI.getWorkbench().getSharedImages().
getImageDescriptor(ISharedImages.IMG_OBJS_INFO_TSK));
I get a problem in DataInterfc interface=new DataInterfc(). Do I need to define the class I want to callin plugin.xml or what to do exact?
Can you help me please

interface is a reserved keyword in Java you cannot use it as a variable name (see here).
Use some other name:
DataInterfc interfce = new DataInterfc();
The DataInterfc class must be defined in your plugin or in a plugin that you declare in your plug-in's dependencies.

interfaces cannot be instantiated, that's just basic Java