nl.toolforge.karma.core.ErrorCode.java Source code

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Here is the source code for nl.toolforge.karma.core.ErrorCode.java

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/*
Karma core - Core of the Karma application
Copyright (C) 2004  Toolforge <www.toolforge.nl>
    
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
    
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.
    
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
package nl.toolforge.karma.core;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.text.MessageFormat;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;

/**
 * <p>Class representing a Karma errorcode. These errorcodes are localized to support different languages. Errorcodes
 * are defined in ranges. Exceptions that are supported by Karma, define these ranges.</p>
 *
 * @author D.A. Smedes
 * @version $Id$
 */
public final class ErrorCode {

    private static Log logger = LogFactory.getLog(ErrorCode.class);

    private static Locale currentLocale = null;

    private Object[] messageArguments = new Object[] {};

    private ResourceBundle messageBundle = null;

    static {

        // todo : ensure that LocalEnvironment knows about the current Locale and pass it on to here.
        //
        currentLocale = Locale.ENGLISH;
    }

    private String errorCode = null;

    /**
     * Creates an error code. Error codes must comply to the following pattern : <code>[A-Z]{3}-\d{5}</code>. Examples are:
     * <code>MAN-00001</code>, <code>CMD-10020</code>.
     *
     * @param errorCode
     */
    public ErrorCode(String errorCode) {

        if (!errorCode.matches("[A-Z]{3}-\\d{5}")) {
            throw new IllegalArgumentException("Illegal error code format.");
        }
        this.errorCode = errorCode;
    }

    public void setMessageBundle(ResourceBundle messageBundle) {
        this.messageBundle = messageBundle;
    }

    /**
     * Assigns message arguments to this error code as per the <code>MessageFormat</code> definition.
     *
     * @param messageArguments An Object array (currently only <code>String</code> instances are supported).
     */
    public final void setMessageArguments(Object[] messageArguments) {
        this.messageArguments = messageArguments;
    }

    /**
     * <p>Gets a localized error message for the <code>ErrorCode</code> instance. Error messages are defined in a
     * <code>error-messages-&lt;locale&gt;.properties</code> (e.g. <code>error-messages-NL.properties</code>). A message
     * text is identified by a key <code>message.</code> concatenated with {@link #getErrorCodeString}.
     * <p/>
     * </p>When no resource bundle can be found for <code>locale</code>, the default locale <code>Locale.ENGLISH</code> is
     * used.
     *
     * @param locale A locale object (e.g. representing the current locale of the user environment).
     * @return A localized error message or {@link #getErrorCodeString} when no message was found for this errorcode or the
     *   resourcebundle could not be found for <code>locale</code>.
     */
    public String getErrorMessage(Locale locale) {

        if (locale == null) {
            locale = currentLocale;
        }

        String message = "";

        if (messageBundle == null) {
            try {
                locale = Locale.ENGLISH;
                messageBundle = ResourceBundle.getBundle("error-messages", locale);
            } catch (MissingResourceException m) {
                logger.error("No default resource bundle available for locale " + locale);
                return getErrorCodeString();
            }
        }

        try {
            message = messageBundle.getString("message." + getErrorCodeString());

            if (getMessageArguments().length != 0) {
                MessageFormat messageFormat = new MessageFormat(message);
                message = messageFormat.format(getMessageArguments());
            }

        } catch (RuntimeException r) {
            logger.error("No message found for errorcode : " + getErrorCodeString());
            message = getErrorCodeString();
        }

        if (message.startsWith(getErrorCodeString())) {
            return message;
        }

        return getErrorCodeString() + " : " + message;
    }

    /**
     * Gets the error message for the current locale.
     *
     * @return The error message for the error code.
     */
    public String getErrorMessage() {
        return getErrorMessage(currentLocale);
    }

    /**
     * Gets this instance' error code.
     *
     * @return This instance' error code.
     */
    public String getErrorCodeString() {
        return errorCode;
    }

    private Object[] getMessageArguments() {
        return (messageArguments == null ? new Object[0] : messageArguments);
    }

    public boolean equals(Object o) {
        if (this == o)
            return true;
        if (!(o instanceof ErrorCode))
            return false;

        final ErrorCode errorCode1 = (ErrorCode) o;

        if (errorCode != null ? !errorCode.equals(errorCode1.errorCode) : errorCode1.errorCode != null)
            return false;

        return true;
    }

    public int hashCode() {
        return (errorCode != null ? errorCode.hashCode() : 0);
    }

    public String toString() {
        return errorCode;
    }

}