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StringManager.javaAPI DocApache Tomcat 6.0.148674Fri Jul 20 04:20:32 BST 2007org.apache.catalina.util

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.

author
James Duncan Davidson [duncan@eng.sun.com]
author
James Todd [gonzo@eng.sun.com]

Fields Summary
private ResourceBundle
bundle
The ResourceBundle for this StringManager.
private static org.apache.juli.logging.Log
log
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.

    
                                                      

       
        String bundleName = packageName + ".LocalStrings";
        try {
            bundle = ResourceBundle.getBundle(bundleName);
            return;
        } catch( MissingResourceException ex ) {
            // Try from the current loader ( that's the case for trusted apps )
            ClassLoader cl=Thread.currentThread().getContextClassLoader();
            if( cl != null ) {
                try {
                    bundle=ResourceBundle.getBundle(bundleName, Locale.getDefault(), cl);
                    return;
                } catch(MissingResourceException ex2) {
                }
            }
            if( cl==null )
                cl=this.getClass().getClassLoader();

            if (log.isDebugEnabled())
                log.debug("Can't find resource " + bundleName +
                    " " + cl);
            if( cl instanceof URLClassLoader ) {
                if (log.isDebugEnabled()) 
                    log.debug( ((URLClassLoader)cl).getURLs());
            }
        }
Methods Summary
public static synchronized org.apache.catalina.util.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 The package name


                                          

          
        StringManager mgr = (StringManager)managers.get(packageName);

        if (mgr == null) {
            mgr = new StringManager(packageName);
            managers.put(packageName, mgr);
        }
        return mgr;
public java.lang.StringgetString(java.lang.String key)
Get a string from the underlying resource bundle.

param
key The resource name

        return MessageFormat.format(getStringInternal(key), (Object [])null);
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 The resource name
param
args Formatting directives

        String iString = null;
        String value = getStringInternal(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
            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";
                }
            }

            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 The resource name
param
arg Formatting directive

        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 The resource name
param
arg1 Formatting directive
param
arg2 Formatting directive

        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 The resource name
param
arg1 Formatting directive
param
arg2 Formatting directive
param
arg3 Formatting directive

        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 The resource name
param
arg1 Formatting directive
param
arg2 Formatting directive
param
arg3 Formatting directive
param
arg4 Formatting directive

        Object[] args = new Object[] {arg1, arg2, arg3, arg4};
        return getString(key, args);
protected java.lang.StringgetStringInternal(java.lang.String key)

        if (key == null) {
            String msg = "key is null";

            throw new NullPointerException(msg);
        }

        String str = null;

        if( bundle==null )
            return key;
        try {
            str = bundle.getString(key);
        } catch (MissingResourceException mre) {
            str = "Cannot find message associated with key '" + key + "'";
        }

        return str;