/*******************************************************************************
* Copyright (c) 2005, 2010 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM - Initial API and implementation
*******************************************************************************/
package org.eclipse.osgi.util;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.*;
import org.eclipse.osgi.framework.debug.Debug;
import org.eclipse.osgi.framework.internal.core.FrameworkProperties;
import org.eclipse.osgi.framework.log.FrameworkLog;
import org.eclipse.osgi.framework.log.FrameworkLogEntry;
/**
* Common superclass for all message bundle classes. Provides convenience
* methods for manipulating messages.
* <p>
* The <code>#bind</code> methods perform string substitution and should be considered a
* convenience and <em>not</em> a full substitute replacement for <code>MessageFormat#format</code>
* method calls.
* </p>
* <p>
* Text appearing within curly braces in the given message, will be interpreted
* as a numeric index to the corresponding substitution object in the given array. Calling
* the <code>#bind</code> methods with text that does not map to an integer will result in an
* {@link IllegalArgumentException}.
* </p>
* <p>
* Text appearing within single quotes is treated as a literal. A single quote is escaped by
* a preceeding single quote.
* </p>
* <p>
* Clients who wish to use the full substitution power of the <code>MessageFormat</code> class should
* call that class directly and not use these <code>#bind</code> methods.
* </p>
* <p>
* Clients may subclass this type.
* </p>
*
* @since 3.1
*/
public abstract class NLS {
private static final Object[] EMPTY_ARGS = new Object[0];
private static final String EXTENSION = ".properties"; //$NON-NLS-1$
private static String[] nlSuffixes;
private static final String PROP_WARNINGS = "osgi.nls.warnings"; //$NON-NLS-1$
private static final String IGNORE = "ignore"; //$NON-NLS-1$
private static final boolean ignoreWarnings = IGNORE.equals(FrameworkProperties.getProperty(PROP_WARNINGS));
/*
* NOTE do not change the name of this field; it is set by the Framework using reflection
*/
private static FrameworkLog frameworkLog;
static final int SEVERITY_ERROR = 0x04;
static final int SEVERITY_WARNING = 0x02;
/*
* This object is assigned to the value of a field map to indicate
* that a translated message has already been assigned to that field.
*/
static final Object ASSIGNED = new Object();
/**
* Creates a new NLS instance.
*/
protected NLS() {
super();
}
/**
* Bind the given message's substitution locations with the given string value.
*
* @param message the message to be manipulated
* @param binding the object to be inserted into the message
* @return the manipulated String
* @throws IllegalArgumentException if the text appearing within curly braces in the given message does not map to an integer
*/
public static String bind(String message, Object binding) {
return internalBind(message, null, String.valueOf(binding), null);
}
/**
* Bind the given message's substitution locations with the given string values.
*
* @param message the message to be manipulated
* @param binding1 An object to be inserted into the message
* @param binding2 A second object to be inserted into the message
* @return the manipulated String
* @throws IllegalArgumentException if the text appearing within curly braces in the given message does not map to an integer
*/
public static String bind(String message, Object binding1, Object binding2) {
return internalBind(message, null, String.valueOf(binding1), String.valueOf(binding2));
}
/**
* Bind the given message's substitution locations with the given string values.
*
* @param message the message to be manipulated
* @param bindings An array of objects to be inserted into the message
* @return the manipulated String
* @throws IllegalArgumentException if the text appearing within curly braces in the given message does not map to an integer
*/
public static String bind(String message, Object[] bindings) {
return internalBind(message, bindings, null, null);
}
/**
* Initialize the given class with the values from the specified message bundle.
*
* @param bundleName fully qualified path of the class name
* @param clazz the class where the constants will exist
*/
public static void initializeMessages(final String bundleName, final Class clazz) {
if (System.getSecurityManager() == null) {
load(bundleName, clazz);
return;
}
AccessController.doPrivileged(new PrivilegedAction() {
public Object run() {
load(bundleName, clazz);
return null;
}
});
}
/*
* Perform the string substitution on the given message with the specified args.
* See the class comment for exact details.
*/
private static String internalBind(String message, Object[] args, String argZero, String argOne) {
if (message == null)
return "No message available."; //$NON-NLS-1$
if (args == null || args.length == 0)
args = EMPTY_ARGS;
int length = message.length();
//estimate correct size of string buffer to avoid growth
int bufLen = length + (args.length * 5);
if (argZero != null)
bufLen += argZero.length() - 3;
if (argOne != null)
bufLen += argOne.length() - 3;
StringBuffer buffer = new StringBuffer(bufLen < 0 ? 0 : bufLen);
for (int i = 0; i < length; i++) {
char c = message.charAt(i);
switch (c) {
case '{' :
int index = message.indexOf('}', i);
// if we don't have a matching closing brace then...
if (index == -1) {
buffer.append(c);
break;
}
i++;
if (i >= length) {
buffer.append(c);
break;
}
// look for a substitution
int number = -1;
try {
number = Integer.parseInt(message.substring(i, index));
} catch (NumberFormatException e) {
throw (IllegalArgumentException) new IllegalArgumentException().initCause(e);
}
if (number == 0 && argZero != null)
buffer.append(argZero);
else if (number == 1 && argOne != null)
buffer.append(argOne);
else {
if (number >= args.length || number < 0) {
buffer.append("<missing argument>"); //$NON-NLS-1$
i = index;
break;
}
buffer.append(args[number]);
}
i = index;
break;
case '\'' :
// if a single quote is the last char on the line then skip it
int nextIndex = i + 1;
if (nextIndex >= length) {
buffer.append(c);
break;
}
char next = message.charAt(nextIndex);
// if the next char is another single quote then write out one
if (next == '\'') {
i++;
buffer.append(c);
break;
}
// otherwise we want to read until we get to the next single quote
index = message.indexOf('\'', nextIndex);
// if there are no more in the string, then skip it
if (index == -1) {
buffer.append(c);
break;
}
// otherwise write out the chars inside the quotes
buffer.append(message.substring(nextIndex, index));
i = index;
break;
default :
buffer.append(c);
}
}
return buffer.toString();
}
/*
* Build an array of property files to search. The returned array contains
* the property fields in order from most specific to most generic.
* So, in the FR_fr locale, it will return file_fr_FR.properties, then
* file_fr.properties, and finally file.properties.
*/
private static String[] buildVariants(String root) {
if (nlSuffixes == null) {
//build list of suffixes for loading resource bundles
String nl = Locale.getDefault().toString();
ArrayList result = new ArrayList(4);
int lastSeparator;
while (true) {
result.add('_' + nl + EXTENSION);
lastSeparator = nl.lastIndexOf('_');
if (lastSeparator == -1)
break;
nl = nl.substring(0, lastSeparator);
}
//add the empty suffix last (most general)
result.add(EXTENSION);
nlSuffixes = (String[]) result.toArray(new String[result.size()]);
}
root = root.replace('.', '/');
String[] variants = new String[nlSuffixes.length];
for (int i = 0; i < variants.length; i++)
variants[i] = root + nlSuffixes[i];
return variants;
}
private static void computeMissingMessages(String bundleName, Class clazz, Map fieldMap, Field[] fieldArray, boolean isAccessible) {
// iterate over the fields in the class to make sure that there aren't any empty ones
final int MOD_EXPECTED = Modifier.PUBLIC | Modifier.STATIC;
final int MOD_MASK = MOD_EXPECTED | Modifier.FINAL;
final int numFields = fieldArray.length;
for (int i = 0; i < numFields; i++) {
Field field = fieldArray[i];
if ((field.getModifiers() & MOD_MASK) != MOD_EXPECTED)
continue;
//if the field has a a value assigned, there is nothing to do
if (fieldMap.get(field.getName()) == ASSIGNED)
continue;
try {
// Set a value for this empty field. We should never get an exception here because
// we know we have a public static non-final field. If we do get an exception, silently
// log it and continue. This means that the field will (most likely) be un-initialized and
// will fail later in the code and if so then we will see both the NPE and this error.
String value = "NLS missing message: " + field.getName() + " in: " + bundleName; //$NON-NLS-1$ //$NON-NLS-2$
if (Debug.DEBUG_MESSAGE_BUNDLES)
System.out.println(value);
log(SEVERITY_WARNING, value, null);
if (!isAccessible)
field.setAccessible(true);
field.set(null, value);
} catch (Exception e) {
log(SEVERITY_ERROR, "Error setting the missing message value for: " + field.getName(), e); //$NON-NLS-1$
}
}
}
/*
* Load the given resource bundle using the specified class loader.
*/
static void load(final String bundleName, Class clazz) {
long start = System.currentTimeMillis();
final Field[] fieldArray = clazz.getDeclaredFields();
ClassLoader loader = clazz.getClassLoader();
boolean isAccessible = (clazz.getModifiers() & Modifier.PUBLIC) != 0;
//build a map of field names to Field objects
final int len = fieldArray.length;
Map fields = new HashMap(len * 2);
for (int i = 0; i < len; i++)
fields.put(fieldArray[i].getName(), fieldArray[i]);
// search the variants from most specific to most general, since
// the MessagesProperties.put method will mark assigned fields
// to prevent them from being assigned twice
final String[] variants = buildVariants(bundleName);
for (int i = 0; i < variants.length; i++) {
// loader==null if we're launched off the Java boot classpath
final InputStream input = loader == null ? ClassLoader.getSystemResourceAsStream(variants[i]) : loader.getResourceAsStream(variants[i]);
if (input == null)
continue;
try {
final MessagesProperties properties = new MessagesProperties(fields, bundleName, isAccessible);
properties.load(input);
} catch (IOException e) {
log(SEVERITY_ERROR, "Error loading " + variants[i], e); //$NON-NLS-1$
} finally {
if (input != null)
try {
input.close();
} catch (IOException e) {
// ignore
}
}
}
computeMissingMessages(bundleName, clazz, fields, fieldArray, isAccessible);
if (Debug.DEBUG_MESSAGE_BUNDLES)
System.out.println("Time to load message bundle: " + bundleName + " was " + (System.currentTimeMillis() - start) + "ms."); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
}
/*
* The method adds a log entry based on the error message and exception.
* The output is written to the System.err.
*
* This method is only expected to be called if there is a problem in
* the NLS mechanism. As a result, translation facility is not available
* here and messages coming out of this log are generally not translated.
*
* @param severity - severity of the message (SEVERITY_ERROR or SEVERITY_WARNING)
* @param message - message to log
* @param e - exception to log
*/
static void log(int severity, String message, Exception e) {
if (severity == SEVERITY_WARNING && ignoreWarnings)
return; // ignoring warnings; bug 292980
if (frameworkLog != null) {
frameworkLog.log(new FrameworkLogEntry("org.eclipse.osgi", severity, 1, message, 0, e, null)); //$NON-NLS-1$
return;
}
String statusMsg;
switch (severity) {
case SEVERITY_ERROR :
statusMsg = "Error: "; //$NON-NLS-1$
break;
case SEVERITY_WARNING :
// intentionally fall through:
default :
statusMsg = "Warning: "; //$NON-NLS-1$
}
if (message != null)
statusMsg += message;
if (e != null)
statusMsg += ": " + e.getMessage(); //$NON-NLS-1$
System.err.println(statusMsg);
if (e != null)
e.printStackTrace();
}
/*
* Class which sub-classes java.util.Properties and uses the #put method
* to set field values rather than storing the values in the table.
*/
private static class MessagesProperties extends Properties {
private static final int MOD_EXPECTED = Modifier.PUBLIC | Modifier.STATIC;
private static final int MOD_MASK = MOD_EXPECTED | Modifier.FINAL;
private static final long serialVersionUID = 1L;
private final String bundleName;
private final Map fields;
private final boolean isAccessible;
public MessagesProperties(Map fieldMap, String bundleName, boolean isAccessible) {
super();
this.fields = fieldMap;
this.bundleName = bundleName;
this.isAccessible = isAccessible;
}
/* (non-Javadoc)
* @see java.util.Hashtable#put(java.lang.Object, java.lang.Object)
*/
public synchronized Object put(Object key, Object value) {
Object fieldObject = fields.put(key, ASSIGNED);
// if already assigned, there is nothing to do
if (fieldObject == ASSIGNED)
return null;
if (fieldObject == null) {
final String msg = "NLS unused message: " + key + " in: " + bundleName;//$NON-NLS-1$ //$NON-NLS-2$
if (Debug.DEBUG_MESSAGE_BUNDLES)
System.out.println(msg);
log(SEVERITY_WARNING, msg, null);
return null;
}
final Field field = (Field) fieldObject;
//can only set value of public static non-final fields
if ((field.getModifiers() & MOD_MASK) != MOD_EXPECTED)
return null;
try {
// Check to see if we are allowed to modify the field. If we aren't (for instance
// if the class is not public) then change the accessible attribute of the field
// before trying to set the value.
if (!isAccessible)
field.setAccessible(true);
// Set the value into the field. We should never get an exception here because
// we know we have a public static non-final field. If we do get an exception, silently
// log it and continue. This means that the field will (most likely) be un-initialized and
// will fail later in the code and if so then we will see both the NPE and this error.
// Extra care is taken to be sure we create a String with its own backing char[] (bug 287183)
// This is to ensure we do not keep the key chars in memory.
field.set(null, new String(((String) value).toCharArray()));
} catch (Exception e) {
log(SEVERITY_ERROR, "Exception setting field value.", e); //$NON-NLS-1$
}
return null;
}
}
}