methodbinding methodexpression valueexpression

1. create MethodBinding MethodBinding methodBinding = FacesContext.getCurrentInstance().getApplication().createMethodBinding("#{bean.method}", null); 

2. create MethodExpression 
        ExpressionFactory expFactory = FacesContext.getCurrentInstance(). 
            getApplication().getExpressionFactory(); 
        ELContext elContext = FacesContext.getCurrentInstance().getELContext(); 
        MethodExpression expression = expFactory.createMethodExpression(elContext, "actionName", String.class, new Class[]{}); 

        commandComponent.setActionExpression(expression); 

3. create ValueExpression 
   ValueExpression valueExpression = expFactory.createValueExpression(elContext, "#{bean.value}", String.class);