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StringManager.javaAPI DocGlassfish v2 API10241Fri May 04 22:33:18 BST 2007org.apache.tomcat.util.res

StringManager

public class StringManager extends Object
An internationalization / localization helper class which reduces the bother of handling ResourceBundles and takes care of the common cases of message formating which otherwise require the creation of Object arrays and such.

The StringManager operates on a package basis. One StringManager per package can be created and accessed via the getManager method call.

The StringManager will look for a ResourceBundle named by the package name given plus the suffix of "LocalStrings". In practice, this means that the localized information will be contained in a LocalStrings.properties file located in the package directory of the classpath.

Please see the documentation for java.util.ResourceBundle for more information.

version
$Revision: 1.3 $ $Date: 2007/05/05 05:33:17 $
author
James Duncan Davidson [duncan@eng.sun.com]
author
James Todd [gonzo@eng.sun.com]
author
Mel Martinez [mmartinez@g1440.com]
see
java.util.ResourceBundle

Fields Summary
private ResourceBundle
bundle
The ResourceBundle for this StringManager.
private static Hashtable
managers
Constructors Summary
private StringManager(String packageName)
Creates a new StringManager for a given package. This is a private method and all access to it is arbitrated by the static getManager method call so that only one StringManager per package will be created.

param
packageName Name of package to create StringManager for.

	this( packageName, Locale.getDefault() );
    
private StringManager(String packageName, Locale loc)

        String bundleName = packageName + ".LocalStrings";
        try {
            bundle = ResourceBundle.getBundle(bundleName,loc);
        } catch( MissingResourceException ex ) {
            bundle= ResourceBundle.getBundle( bundleName, Locale.US);
        }
    
private StringManager(ResourceBundle bundle)

	this.bundle=bundle;
    
Methods Summary
public static synchronized org.apache.tomcat.util.res.StringManagergetManager(java.lang.String packageName)
Get the StringManager for a particular package. If a manager for a package already exists, it will be reused, else a new StringManager will be created and returned.

param
packageName


                                       

          
      StringManager mgr = (StringManager)managers.get(packageName);
      if (mgr == null) {
          mgr = new StringManager(packageName);
          managers.put(packageName, mgr);
      }
      return mgr;
    
public static synchronized org.apache.tomcat.util.res.StringManagergetManager(java.util.ResourceBundle bundle)
Get the StringManager for a particular package. If a manager for a package already exists, it will be reused, else a new StringManager will be created and returned.

param
packageName

      return new StringManager( bundle );
    
public static synchronized org.apache.tomcat.util.res.StringManagergetManager(java.lang.String packageName, java.util.Locale loc)
Get the StringManager for a particular package and Locale. If a manager for a package already exists, it will be reused, else a new StringManager will be created for that Locale and returned.

param
packageName

      StringManager mgr = (StringManager)managers.get(packageName+"_"+loc.toString());
      if (mgr == null) {
          mgr = new StringManager(packageName,loc);
          managers.put(packageName+"_"+loc.toString(), mgr);
      }
      return mgr;
    
public java.lang.StringgetString(java.lang.String key)
Get a string from the underlying resource bundle or return null if the String is not found.

param
key to desired resource String
return
resource String matching key from underlying bundle or null if not found.
throws
IllegalArgumentException if key is null.

        if(key == null){
            String msg = "key may not have a null value";

            throw new IllegalArgumentException(msg);
        }

        String str = null;

        try{
	        str = bundle.getString(key);
        }catch(MissingResourceException mre){
            //bad: shouldn't mask an exception the following way:
            //   str = "[cannot find message associated with key '" + key + "' due to " + mre + "]";
	        //     because it hides the fact that the String was missing
	        //     from the calling code.
	        //good: could just throw the exception (or wrap it in another)
	        //      but that would probably cause much havoc on existing
	        //      code.
	        //better: consistent with container pattern to
	        //      simply return null.  Calling code can then do
	        //      a null check.
	        str = null;
        }

        return str;
    
public java.lang.StringgetString(java.lang.String key, java.lang.Object[] args)
Get a string from the underlying resource bundle and format it with the given set of arguments.

param
key
param
args

        String iString = null;
        String value = getString(key);

        // this check for the runtime exception is some pre 1.1.6
        // VM's don't do an automatic toString() on the passed in
        // objects and barf out

        try {
            // ensure the arguments are not null so pre 1.2 VM's don't barf
            if(args==null){
                args = new Object[1];
            }
            
            Object[] nonNullArgs = args;
            for (int i=0; i<args.length; i++) {
                if (args[i] == null) {
                    if (nonNullArgs==args){
                        nonNullArgs=(Object[])args.clone();
                    }
                    nonNullArgs[i] = "null";
                }
            }
            if( value==null ) value=key;
            iString = MessageFormat.format(value, nonNullArgs);
        } catch (IllegalArgumentException iae) {
            StringBuffer buf = new StringBuffer();
            buf.append(value);
            for (int i = 0; i < args.length; i++) {
                buf.append(" arg[" + i + "]=" + args[i]);
            }
            iString = buf.toString();
        }
        return iString;
    
public java.lang.StringgetString(java.lang.String key, java.lang.Object arg)
Get a string from the underlying resource bundle and format it with the given object argument. This argument can of course be a String object.

param
key
param
arg

	Object[] args = new Object[] {arg};
	return getString(key, args);
    
public java.lang.StringgetString(java.lang.String key, java.lang.Object arg1, java.lang.Object arg2)
Get a string from the underlying resource bundle and format it with the given object arguments. These arguments can of course be String objects.

param
key
param
arg1
param
arg2

	Object[] args = new Object[] {arg1, arg2};
	return getString(key, args);
    
public java.lang.StringgetString(java.lang.String key, java.lang.Object arg1, java.lang.Object arg2, java.lang.Object arg3)
Get a string from the underlying resource bundle and format it with the given object arguments. These arguments can of course be String objects.

param
key
param
arg1
param
arg2
param
arg3

	Object[] args = new Object[] {arg1, arg2, arg3};
	return getString(key, args);
    
public java.lang.StringgetString(java.lang.String key, java.lang.Object arg1, java.lang.Object arg2, java.lang.Object arg3, java.lang.Object arg4)
Get a string from the underlying resource bundle and format it with the given object arguments. These arguments can of course be String objects.

param
key
param
arg1
param
arg2
param
arg3
param
arg4

	Object[] args = new Object[] {arg1, arg2, arg3, arg4};
	return getString(key, args);