/*
* Copyright (C) 2007 Sun Microsystems, Inc. All rights reserved. Use is
* subject to license terms.
*/
package org.jdesktop.el;
import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
/**
*
* <p>Utility methods for this portion of the EL implementation</p>
*
* <p>Methods on this class use a Map instance stored in ThreadLocal storage
* to minimize the performance impact on operations that take place multiple
* times on a single Thread. The keys and values of the Map
* are implementation private.</p>
*
* @author edburns
*/
class ELUtil {
/**
* <p>This class may not be constructed.</p>
*/
private ELUtil() {
}
/**
* <p>The <code>ThreadLocal</code> variable used to record the
* {@link FacesContext} instance for each processing thread.</p>
*/
private static ThreadLocal instance = new ThreadLocal() {
protected Object initialValue() { return (null); }
};
/**
* @return a Map stored in ThreadLocal storage. This may
* be used by methods of this class to minimize the performance
* impact for operations that may take place multiple times on a given
* Thread instance.
*/
private static Map getCurrentInstance() {
Map result = (Map) instance.get();
if (null == result) {
result = new HashMap();
setCurrentInstance(result);
}
return result;
}
/**
* <p>Replace the Map with the argument context.</p>
*
* @param context the Map to be stored in ThreadLocal storage.
*/
private static void setCurrentInstance(Map context) {
instance.set(context);
}
/*
* <p>Convenience method, calls through to
* {@link #getExceptionMessageString(javax.el.ELContext,java.lang.String,Object []).
* </p>
*
* @param context the ELContext from which the Locale for this message
* is extracted.
*
* @param messageId the messageId String in the ResourceBundle
*
* @return a localized String for the argument messageId
*/
public static String getExceptionMessageString(ELContext context, String messageId) {
return getExceptionMessageString(context, messageId, null);
}
/*
* <p>Return a Localized message String suitable for use as an Exception message.
* Examine the argument <code>context</code> for a <code>Locale</code>. If
* not present, use <code>Locale.getDefault()</code>. Load the
* <code>ResourceBundle</code> "javax.el.Messages" using that locale. Get
* the message string for argument <code>messageId</code>. If not found
* return "Missing Resource in EL implementation ??? messageId ???"
* with messageId substituted with the runtime
* value of argument <code>messageId</code>. If found, and argument
* <code>params</code> is non-null, format the message using the
* params. If formatting fails, return a sensible message including
* the <code>messageId</code>. If argument <code>params</code> is
* <code>null</code>, skip formatting and return the message directly, otherwise
* return the formatted message.</p>
*
* @param context the ELContext from which the Locale for this message
* is extracted.
*
* @param messageId the messageId String in the ResourceBundle
*
* @param params parameters to the message
*
* @return a localized String for the argument messageId
*/
public static String getExceptionMessageString(ELContext context,
String messageId,
Object [] params) {
String result = "";
Locale locale = null;
if (null == context || null == messageId) {
return result;
}
if (null == (locale = context.getLocale())) {
locale = Locale.getDefault();
}
if (null != locale) {
Map threadMap = getCurrentInstance();
ResourceBundle rb = null;
if (null == (rb = (ResourceBundle)
threadMap.get(locale.toString()))) {
rb = ResourceBundle.getBundle("org.jdesktop.el.PrivateMessages",
locale);
threadMap.put(locale.toString(), rb);
}
if (null != rb) {
try {
result = rb.getString(messageId);
if (null != params) {
result = MessageFormat.format(result, params);
}
} catch (IllegalArgumentException iae) {
result = "Can't get localized message: parameters to message appear to be incorrect. Message to format: " + messageId;
} catch (MissingResourceException mre) {
result = "Missing Resource in EL implementation: ???" + messageId + "???";
} catch (Exception e) {
result = "Exception resolving message in EL implementation: ???" + messageId + "???";
}
}
}
return result;
}
}