How to reduce coding by extending Managed Beans

After coding many backing/managed beans it became clear to me that there were a few things that I seem to be doing over and over, these were:

• Getting values from the binding layer
• Setting values in the binding layer
• Executing operation bindings
• Using a combination of the above in a backing bean method

The logical thing to do was be to but my code for doing this into a class and extend this class for all of my managed beans. The class is called JSFBean and uses the binding "#{bindings}" to access the binding container. The three methods in the class (so far) are: execute, getValue and setValue.

The bean which I have called JSFBean includes these three methods and some basic error handling. When creating a backing bean simply add "extends JSFBean" to the class definition.

JSFBean.java:

package com.delexian.ui.backing;

import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;
import oracle.adf.model.binding.DCBindingContainer;
import oracle.binding.OperationBinding;

public class JSFBean {

    public JSFBean() {
    }

    public DCBindingContainer getBindings() {
        FacesContext fc = FacesContext.getCurrentInstance();
        ValueBinding vb = fc.getApplication().createValueBinding("#{bindings}");
        DCBindingContainer dc = (DCBindingContainer) vb.getValue(fc);
 
        return dc;
    }

    public boolean execute(String operation){
        DCBindingContainer bindings = getBindings();
        OperationBinding operationBinding = bindings.getOperationBinding(operation);
        if (operationBinding == null){
            FacesContext fc = FacesContext.getCurrentInstance();
            fc.addMessage("Invalid Operation", new FacesMessage(operation + " is not a valid operation for this page"));
            return true;    
        }
 
        operationBinding.execute();
 
        return operationBinding.getErrors().isEmpty();
    }

    public Object getValue(String el){
             FacesContext fc = FacesContext.getCurrentInstance();
             ValueBinding expr = fc.getApplication().createValueBinding(el);
             return expr.getValue(fc);
         }
  
    public void setValue(String el, Object value){
        FacesContext fc = FacesContext.getCurrentInstance();
        ValueBinding expr = fc.getApplication().createValueBinding(el);
        expr.setValue(fc, value);
 
    }

}

An example usage in a backing bean Employees.java, extends JSFBean:

package com.delexian.ui.backing;

public class Employees extends JSFBean {
    public Employees() {
    }

    public String calculate_action() {
        execute("CalculateCommission");
        execute("Commit");
        return null;
    }
}