com.gettextresourcebundle.GettextResourceBundle.java Source code

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Here is the source code for com.gettextresourcebundle.GettextResourceBundle.java

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/**
 * Copyright (c) 2012 Tom Schaible See the file license.txt for copying permission.
 */
package com.gettextresourcebundle;

import java.io.IOException;
import java.io.LineNumberReader;
import java.io.Reader;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.ResourceBundle;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang3.StringEscapeUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author Tom Schaible
 * 
 *         A resource bundle that is created from a gettext PO file
 */
public class GettextResourceBundle extends ResourceBundle {
    private static final Logger LOG = LoggerFactory.getLogger(GettextResourceBundle.class);

    private static final Pattern LINE_PATTERN = Pattern.compile("^([\\w_\\[\\]]*)\\s*\\\"(.*)\\\"$");

    private Map<String, Object> resources = new HashMap<String, Object>();;

    public GettextResourceBundle(Reader reader) {
        init(new LineNumberReader(reader));
    }

    /**
     * initialize the ResourceBundle from a PO file
     * 
     * if
     * 
     * @param reader the reader to read the contents of the PO file from
     */
    private void init(LineNumberReader reader) {
        if (reader != null) {
            String line = null;
            String key = null;
            String value = null;
            try {
                while ((line = reader.readLine()) != null) {
                    if (line.startsWith("#")) {
                        LOG.trace(reader.getLineNumber() + ": Parsing PO file, comment skipped [" + line + "]");
                    } else if (line.trim().length() == 0) {
                        LOG.trace(reader.getLineNumber() + ": Parsing PO file, whitespace line skipped");
                    } else {
                        Matcher matcher = LINE_PATTERN.matcher(line);
                        if (matcher.matches()) {
                            String type = matcher.group(1);
                            String str = matcher.group(2);
                            if ("msgid".equals(type)) {
                                if (key != null && value != null) {
                                    LOG.debug(
                                            "Parsing PO file, key,value pair found [" + key + " => " + value + "]");
                                    resources.put(StringEscapeUtils.unescapeJava(key),
                                            StringEscapeUtils.unescapeJava(value));
                                    key = null;
                                    value = null;
                                }
                                key = str;
                                LOG.trace(reader.getLineNumber() + ": Parsing PO file, msgid found [" + key + "]");
                            } else if ("msgstr".equals(type)) {
                                value = str;
                                LOG.trace(
                                        reader.getLineNumber() + ": Parsing PO file, msgstr found [" + value + "]");
                            } else if (type == null || type.length() == 0) {
                                if (value == null) {
                                    LOG.trace(reader.getLineNumber()
                                            + ": Parsing PO file, addition to msgid found [" + str + "]");
                                    key += str;
                                } else {
                                    LOG.trace(reader.getLineNumber()
                                            + ": Parsing PO file, addition to msgstr found [" + str + "]");
                                    value += str;
                                }

                            }
                        } else {
                            LOG.error(reader.getLineNumber() + ": Parsing PO file, invalid syntax [" + line + "]");
                        }
                    }

                }

                if (key != null && value != null) {
                    LOG.debug("Parsing PO file, key,value pair found [" + key + " => " + value + "]");
                    resources.put(StringEscapeUtils.unescapeJava(key), StringEscapeUtils.unescapeJava(value));
                    key = null;
                    value = null;
                }
            } catch (IOException e) {
                LOG.error("GettextResourceBundle could not be initialized", e);
            }

        } else {
            LOG.warn("GettextResourceBundle could not be initialized, input was null");
        }
        LOG.info("GettextResourceBundle initialization complete, " + resources.size() + " resources loaded");
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.util.ResourceBundle#getKeys()
     */
    @Override
    public Enumeration<String> getKeys() {
        return Collections.enumeration(resources.keySet());
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.util.ResourceBundle#handleGetObject(java.lang.String)
     */
    @Override
    protected Object handleGetObject(String key) {
        return resources.get(key);
    }
}