BaseConverter.java

package humanize.faces.convert;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;

import javax.faces.component.PartialStateHolder;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;

import com.google.common.base.Preconditions;

public abstract class BaseConverter implements Converter, Serializable, PartialStateHolder
{

    private static final long serialVersionUID = -7333204612599724969L;

    private Locale locale;

    private boolean initialState;

    private boolean transientFlag = false;

    @Override
    public void clearInitialState()
    {

        initialState = false;

    }

    @Override
    public Object getAsObject(FacesContext context, UIComponent component, String value)
    {

        return value;

    }

    public Locale getLocale()
    {

        if (locale == null)
        {
            locale = getLocale(FacesContext.getCurrentInstance());
        }

        return locale;

    }

    @Override
    public boolean initialStateMarked()
    {

        return initialState;

    }

    @Override
    public boolean isTransient()
    {

        return transientFlag;

    }

    @Override
    public void markInitialState()
    {

        initialState = true;

    }

    @Override
    public void restoreState(FacesContext context, Object state)
    {

        Preconditions.checkNotNull(context);

        if (state != null)
        {
            @SuppressWarnings("unchecked")
            List<Object> values = (List<Object>) state;
            Iterator<Object> iterator = values.iterator();
            locale = (Locale) iterator.next();
            restore(iterator);
        }

    }

    @Override
    public Object saveState(FacesContext context)
    {

        Preconditions.checkNotNull(context);

        if (!initialStateMarked())
        {
            List<Object> states = new ArrayList<Object>();
            states.add(locale);
            save(states);
            return states;
        }

        return null;
    }

    public void setLocale(Locale locale)
    {

        clearInitialState();
        this.locale = locale;

    }

    @Override
    public void setTransient(boolean transientFlag)
    {

        this.transientFlag = transientFlag;

    }

    protected Date asDate(Object value)
    {

        if (Date.class.isAssignableFrom(value.getClass()))
        {
            return (Date) value;
        } else
        {
            return new Date(Long.parseLong(value.toString()));
        }

    }

    protected Number asNumber(Object input)
    {

        if (input instanceof String)
        {
            try
            {
                String istr = (String) input;
                return (istr.indexOf('.') != -1) ? Double.valueOf(istr) : Long.valueOf(istr);
            } catch (NumberFormatException nfe)
            {
                throw new IllegalArgumentException(nfe);
            }
        }

        return (Number) input;

    }

    protected Locale getLocale(FacesContext context)
    {

        return locale == null ? context.getViewRoot().getLocale() : locale;

    }

    protected void restore(Iterator<Object> iterator)
    {

        //

    }

    protected void save(List<Object> states)
    {

        //

    }
}