✔ JSF Converter - Parameter übergeben

A

alan79

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Ich versuche einen flexiblen converter zu schreiben, welcher parameter gesteuert den von z.B. "outputText" übergebenen Wert verändert:
- substring
- newlines entfernen
- etc.

Ich habe mir als Vorlage den Standard Converter "DateTimeConverter" angesehen:
Code: 
/*
 * Copyright 2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package javax.faces.convert;

import javax.faces.component.UIComponent;
import javax.faces.component.StateHolder;
import javax.faces.context.FacesContext;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;

/**
 * see Javadoc of <a href="http://java.sun.com/javaee/javaserverfaces/1.2/docs/api/index.html">JSF Specification</a>
 *
 * @author Thomas Spiegl (latest modification by $Author: pmcmahan $)
 * @version $Revision: 529409 $ $Date: 2007-04-16 16:38:37 -0500 (Mon, 16 Apr 2007) $
 */
public class DateTimeConverter
        implements Converter, StateHolder
{

    // API field
    public static final String CONVERTER_ID = "javax.faces.DateTime";
    public static final String DATE_ID = "javax.faces.converter.DateTimeConverter.DATE";
    public static final String DATETIME_ID = "javax.faces.converter.DateTimeConverter.DATETIME";
    public static final String STRING_ID = "javax.faces.converter.STRING";
    public static final String TIME_ID = "javax.faces.converter.DateTimeConverter.TIME";

    // internal constants
    private static final String TYPE_DATE = "date";
    private static final String TYPE_TIME = "time";
    private static final String TYPE_BOTH = "both";
    private static final String STYLE_DEFAULT = "default";
    private static final String STYLE_MEDIUM = "medium";
    private static final String STYLE_SHORT = "short";
    private static final String STYLE_LONG = "long";
    private static final String STYLE_FULL = "full";
    private static final TimeZone TIMEZONE_DEFAULT = TimeZone.getTimeZone("GMT");

    private String _dateStyle;
    private Locale _locale;
    private String _pattern;
    private String _timeStyle;
    private TimeZone _timeZone;
    private String _type;
    private boolean _transient;

    // CONSTRUCTORS
    public DateTimeConverter()
    {
    }

    // METHODS
    public Object getAsObject(FacesContext facesContext, UIComponent uiComponent, String value)
    {
        if (facesContext == null) throw new NullPointerException("facesContext");
        if (uiComponent == null) throw new NullPointerException("uiComponent");

        if (value != null)
        {
            value = value.trim();
            if (value.length() > 0)
            {
                DateFormat format = getDateFormat();
                TimeZone tz = getTimeZone();
                if( tz != null )
                    format.setTimeZone( tz );
                try
                {
                    return format.parse(value);
                }
                catch (ParseException e)
                {
                	try {
                		String type = getType();
                		Object[] args = new Object[]{value,format.parse(new Date().toString()),_MessageUtils.getLabel(facesContext, uiComponent)};
                		
                		if(type.equals(TYPE_DATE))
                			throw new ConverterException(_MessageUtils.getErrorMessage(facesContext,DATE_ID,args));
                		else if (type.equals(TYPE_TIME))
                			throw new ConverterException(_MessageUtils.getErrorMessage(facesContext,TIME_ID,args));
                		else if (type.equals(TYPE_BOTH))
                			throw new ConverterException(_MessageUtils.getErrorMessage(facesContext,DATETIME_ID,args));
                		else
                			throw new ConverterException("invalid type '" + _type + "'");
                	}catch(ParseException exception) {
                		throw new ConverterException(exception);
                	}
                }
            }
        }
        return null;
    }

    public String getAsString(FacesContext facesContext, UIComponent uiComponent, Object value)
    {
        if (facesContext == null) throw new NullPointerException("facesContext");
        if (uiComponent == null) throw new NullPointerException("uiComponent");

        if (value == null)
        {
            return "";
        }
        if (value instanceof String)
        {
            return (String)value;
        }

        DateFormat format = getDateFormat();
        TimeZone tz = getTimeZone(); 
        if (tz != null)
        {
            format.setTimeZone(tz);
        }
        try
        {
            return format.format(value);
        }
        catch (Exception e)
        {
        	throw new ConverterException(_MessageUtils.getErrorMessage(facesContext, STRING_ID, new Object[]{value,_MessageUtils.getLabel(facesContext, uiComponent)}),e);
        }
    }

    private DateFormat getDateFormat()
    {
        String type = getType();
        DateFormat format;
        if (_pattern != null)
        {
            try 
            {
                format = new SimpleDateFormat(_pattern, getLocale());
            } 
                catch (IllegalArgumentException iae)
            {
                throw new ConverterException("Invalid pattern", iae);    
            }
        }
        else if (type.equals(TYPE_DATE))
        {
            format = DateFormat.getDateInstance(calcStyle(getDateStyle()), getLocale());
        }
        else if (type.equals(TYPE_TIME))
        {
            format = DateFormat.getTimeInstance(calcStyle(getTimeStyle()), getLocale());
        }
        else if (type.equals(TYPE_BOTH))
        {
            format = DateFormat.getDateTimeInstance(calcStyle(getDateStyle()),
                                                    calcStyle(getTimeStyle()),
                                                    getLocale());
        }
        else
        {
            throw new ConverterException("invalid type '" + _type + "'");
        }
        
        // format cannot be lenient (JSR-127)
        format.setLenient(false);
        return format;
    }

    private int calcStyle(String name)
    {
        if (name.equals(STYLE_DEFAULT))
        {
            return DateFormat.DEFAULT;
        }
        if (name.equals(STYLE_MEDIUM))
        {
            return DateFormat.MEDIUM;
        }
        if (name.equals(STYLE_SHORT))
        {
            return DateFormat.SHORT;
        }
        if (name.equals(STYLE_LONG))
        {
            return DateFormat.LONG;
        }
        if (name.equals(STYLE_FULL))
        {
            return DateFormat.FULL;
        }

        throw new ConverterException("invalid style '" + name + "'");
    }

    // STATE SAVE/RESTORE
    public void restoreState(FacesContext facesContext, Object state)
    {
        Object[] values = (Object[])state;
        _dateStyle = (String)values[0];
        _locale = (Locale)values[1];
        _pattern = (String)values[2];
        _timeStyle = (String)values[3];
        _timeZone = (TimeZone)values[4];
        _type = (String)values[5];
    }

    public Object saveState(FacesContext facesContext)
    {
        Object[] values = new Object[6];
        values[0] = _dateStyle;
        values[1] = _locale;
        values[2] = _pattern;
        values[3] = _timeStyle;
        values[4] = _timeZone;
        values[5] = _type;
        return values;
    }

    // GETTER & SETTER
    public String getDateStyle()
    {
        return _dateStyle != null ? _dateStyle : STYLE_DEFAULT;
    }

    public void setDateStyle(String dateStyle)
    {
        //TODO: validate timeStyle
        _dateStyle = dateStyle;
    }

    public Locale getLocale()
    {
        if (_locale != null) return _locale;
        FacesContext context = FacesContext.getCurrentInstance();
        return context.getViewRoot().getLocale();
    }

    public void setLocale(Locale locale)
    {
        _locale = locale;
    }

    public String getPattern()
    {
        return _pattern;
    }

    public void setPattern(String pattern)
    {
        _pattern = pattern;
    }

    public String getTimeStyle()
    {
        return _timeStyle != null ? _timeStyle : STYLE_DEFAULT;
    }

    public void setTimeStyle(String timeStyle)
    {
        //TODO: validate timeStyle
        _timeStyle = timeStyle;
    }

    public TimeZone getTimeZone()
    {
        return _timeZone != null ? _timeZone : TIMEZONE_DEFAULT;
    }

    public void setTimeZone(TimeZone timeZone)
    {
        _timeZone = timeZone;
    }

    public boolean isTransient()
    {
        return _transient;
    }

    public void setTransient(boolean aTransient)
    {
        _transient = aTransient;
    }

    public String getType()
    {
        return _type != null ? _type : TYPE_DATE;
    }

    public void setType(String type)
    {
        //TODO: validate type
        _type = type;
    }
}
Diesem Converter können folgende Parameter übergeben werden:
dateStyle, locale, pattern, timeStyle, timeZone, type

Soweit ich das Verstanden habe werden in der Methode "restoreState" die privaten properties abgefüllt.
Zusatzfrage: Wie, und wo wird das Array state abgefüllt? Spielt hier die Reihenfolge der Parametereingabe in der JSF page ein Rolle?

Ich habe versucht das Ganze zu kopieren, jedoch krieg ich das nicht hin.
1. Die Methode restoreState wird nie aufgerufen
2. Die Methode getAsObject wird nie aufgerufen
-> Sämtliche Properties sind null d.h. die Paremeter funktionieren nicht.

Hier ist meine Klasse:
Code: 
package com.antavis.groupware.converters;

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

import org.apache.log4j.Logger;

public final class OutputTextConverter implements Converter,  StateHolder  {

	private String _substring;
	private String _maxNewLine;
	private boolean _transient;
	private static Logger log = Logger.getLogger(OutputTextConverter.class);


	public OutputTextConverter() {
				
	}

	public Object getAsObject( FacesContext facesContext, UIComponent uiComponent, String value ) {
		if (facesContext == null) throw new NullPointerException("facesContext");
		if (uiComponent == null) throw new NullPointerException("uiComponent");

		System.out.println("Debug converter - getAsObject has been called..");
		if (value != null)
		{
			value = value.trim();
			if (value.length() > 0)
			{
				System.out.println("Debug converter (getasobject): - substring value: "+_substring);
				if (_substring!=null){
					Integer substr = Integer.parseInt(_substring.trim());
					Integer valueLng = value.length();

					if (substr<valueLng)
					{
						value = value.substring(0,substr);

					}
				}
			}

		}

		return value;
	}

	public String getAsString( FacesContext facesContext, UIComponent uiComponent, Object val) {
		if (facesContext == null) throw new NullPointerException("facesContext");
		if (uiComponent == null) throw new NullPointerException("uiComponent");
		System.out.println("Debug converter - getAsString has been called..");
				

		String value = (String) val;
		if (value != null)
		{
			
			value = value.trim();
			if (value.length() > 0)
			{
				System.out.println("Debug converter (getasstring): - substring value: "+_substring);
				if (_substring!=null){
					Integer substr = Integer.parseInt(_substring.trim());
					Integer valueLng = value.length();

					if (substr<valueLng)
					{
						value = value.substring(0,substr);

					}
				}
			}

		}

		return value;
	}


	// STATE SAVE/RESTORE
	public void restoreState(FacesContext facesContext, Object state)
	{
		System.out.println("Debug converter - restoreState() has been called..");
		Object[] values = (Object[])state;
		_substring = (String)values[0];
		_maxNewLine = (String)values[1];

	}

	public Object saveState(FacesContext facesContext)
	{
		System.out.println("Debug converter - saveState() has been called..");
		Object[] values = new Object[2];
		values[0] = _substring;
		values[1] = _maxNewLine;

		return values;
	}


	private Integer countNewLines(String value){
		/*
		 * TODO countNewLines 
		 */
		 Integer count = 0;

		 return count;
	}

	private String substrNewLines(String value, Integer lines){
		/*
		 * TODO substrNewLines
		 */
		return value;
	}


	public String getSubstring() {
		return _substring;
	}

	public void setSubstring(String substring) {
		_substring = substring;
	}

	public String getMaxNewLine() {
		return _maxNewLine;
	}

	public void setMaxNewLine(String newLine) {
		_maxNewLine = newLine;
	}

	public boolean isTransient()
	{
		return _transient;
	}

	public void setTransient(boolean aTransient)
	{
		_transient = aTransient;
	}


}

Ich habe zu Debug Zwecken ein paar Consolen Outputs hinzugefügt:
Wenn ich die Seite aufrufen spuckt die Console folgendes aus:
Debug converter - getAsString has been called..
Debug converter (getasstring): - substring value: null
Debug converter - getAsString has been called..
Debug converter (getasstring): - substring value: null
Debug converter - getAsString has been called..
Debug converter (getasstring): - substring value: null
Debug converter - saveState() has been called..

Hat jemand eine Idee was ich falsch mache?
Vielen Dank und Grüsse
Alan
 
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