org.pdfsam.emp4j.messages.sources.XmlMessagesSource.java Source code

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Here is the source code for org.pdfsam.emp4j.messages.sources.XmlMessagesSource.java

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/*
 * Created on 21-June-2006
 * Copyright (C) 2006 by Andrea Vacondio.
 *
 *
 * This library is provided under dual licenses.
 * You may choose the terms of the Lesser General Public License version 2.1 or the General Public License version 2
 * License at your discretion.
 * 
 * 
 * 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;
 * version 2.1 of the License.
 * 
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * 
 * 
 * This program is free software; you can redistribute it and/or modify it under the terms of the 
 * GNU General Public License as published by the Free Software Foundation; 
 * either version 2 of the License.
 * 
 * This program 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 General Public License for more details.
 * You should have received a copy of the GNU General Public License along with this program; 
 * if not, write to the Free Software Foundation, Inc., 
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package org.pdfsam.emp4j.messages.sources;

import java.io.File;
import java.net.URL;
import org.dom4j.Document;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;
import org.pdfsam.emp4j.messages.interfaces.AbstractMessagesSource;
import org.w3c.dom.DOMException;

/**
 * Implementation of the MessageSourceInterface. It gets exception messages from an xml source
 * @author Andrea Vacondio
 */
public class XmlMessagesSource extends AbstractMessagesSource {

    private static final long serialVersionUID = -5549563695772599153L;
    private transient Document document;

    public XmlMessagesSource(Node node) throws Exception {
        super(node);
        Node arg1 = node.selectSingleNode("xmlsource/@filename");
        if (arg1 != null) {
            document = getDocument(arg1.getText());
        } else {
            throw new DOMException(DOMException.NOT_FOUND_ERR, "Error reading configuration node, node is null.");
        }
    }

    /**
     * This method tries to get the Document containing the exception messages. First it tries using
     * <code>filename</code> as a path to file. Second it tries to use it as Resource name or a SystemResource name.
     * @param filename
     * @return the Document object
     * @throws Exception
     */
    private Document getDocument(String filename) throws Exception {
        Document retVal;
        SAXReader reader = new SAXReader();
        File resourceFile = new File(filename);
        if (resourceFile.exists()) {
            retVal = reader.read(resourceFile);
        } else {
            ClassLoader cl = XmlMessagesSource.class.getClassLoader();
            URL resourceUrl = null;
            if (cl != null) {
                resourceUrl = cl.getResource(filename);
            } else {
                resourceUrl = ClassLoader.getSystemResource(filename);
            }
            if (resourceUrl != null) {
                retVal = reader.read(resourceUrl);
            } else {
                throw new NullPointerException("Cannot locate XmlMessageSource data file.");
            }
        }
        return retVal;
    }

    public String getLocalizedExceptionMessage(Object exceptionTypeKey, int exceptionErrorCode) throws Exception {
        return getExceptionMessage(exceptionTypeKey, exceptionErrorCode);
    }

    public String getExceptionMessage(Object exceptionTypeKey, int exceptionErrorCode) throws Exception {
        StringBuffer sb = new StringBuffer();
        sb.append(getTypeDescription(exceptionTypeKey.toString()));
        sb.append(padString(Integer.toString(exceptionErrorCode), 3, '0', true));
        sb.append(" - ");
        Node node = document.selectSingleNode("/exception-types/type[@key=\"" + exceptionTypeKey.toString()
                + "\"]/exception[@errorcode=\"" + exceptionErrorCode + "\"]/@message");
        if (node != null) {
            sb.append(node.getText());
        }
        return sb.toString();
    }

    /**
     * @param exceptionTypeKey
     *        the given exception type key
     * @return the associated description
     * @throws Exception
     */
    private String getTypeDescription(String exceptionTypeKey) throws Exception {
        String retVal = "UNK";
        Node node = document
                .selectSingleNode("/exception-types/type[@key=\"" + exceptionTypeKey + "\"]/@description");
        if (node != null) {
            retVal = node.getText();
        }
        return retVal;
    }

    /**
     * Given a string s, length n it fills with char c till length n
     * @param s
     *        input String
     * @param n
     *        output string length
     * @param c
     *        char
     * @param paddingLeft
     *        if <code>true</code> chars are added to the left.
     */
    private String padString(String s, int n, char c, boolean paddingLeft) {
        StringBuffer str = new StringBuffer(s);
        int strLength = str.length();
        if (n > 0 && n > strLength) {
            for (int i = 0; i <= n; i++) {
                if (paddingLeft) {
                    if (i < n - strLength) {
                        str.insert(0, c);
                    }
                } else {
                    if (i > strLength) {
                        str.append(c);
                    }
                }
            }
        }
        return str.toString();
    }
}