* This class cannot be instantiated. It has only static methods. *
* The mention of URL in the documentation for this class refers to * a URL string as defined by RFC 1738 and its related RFCs. It is * any string that conforms to the syntax described therein, and * may not always have corresponding support in the java.net.URL * class or Web browsers. *
* NamingManager is safe for concurrent access by multiple threads. *
* Except as otherwise noted, * a Name or environment parameter * passed to any method is owned by the caller. * The implementation will not modify the object or keep a reference * to it, although it may keep a reference to a clone or copy. * * @author Rosanna Lee * @author Scott Seligman * @since 1.3 */ public class NamingManager { /* * Disallow anyone from creating one of these. * Made package private so that DirectoryManager can subclass. */ NamingManager() {} // should be protected and package private static final VersionHelper helper = VersionHelper.getVersionHelper(); // --------- object factory stuff /** * Package-private; used by DirectoryManager and NamingManager. */ private static ObjectFactoryBuilder object_factory_builder = null; /** * The ObjectFactoryBuilder determines the policy used when * trying to load object factories. * See getObjectInstance() and class ObjectFactory for a description * of the default policy. * setObjectFactoryBuilder() overrides this default policy by installing * an ObjectFactoryBuilder. Subsequent object factories will * be loaded and created using the installed builder. *
* The builder can only be installed if the executing thread is allowed * (by the security manager's checkSetFactory() method) to do so. * Once installed, the builder cannot be replaced. *
* @param builder The factory builder to install. If null, no builder * is installed. * @exception SecurityException builder cannot be installed * for security reasons. * @exception NamingException builder cannot be installed for * a non-security-related reason. * @exception IllegalStateException If a factory has already been installed. * @see #getObjectInstance * @see ObjectFactory * @see ObjectFactoryBuilder * @see java.lang.SecurityManager#checkSetFactory */ public static synchronized void setObjectFactoryBuilder( ObjectFactoryBuilder builder) throws NamingException { if (object_factory_builder != null) throw new IllegalStateException("ObjectFactoryBuilder already set"); SecurityManager security = System.getSecurityManager(); if (security != null) { security.checkSetFactory(); } object_factory_builder = builder; } /** * Used for accessing object factory builder. */ static synchronized ObjectFactoryBuilder getObjectFactoryBuilder() { return object_factory_builder; } /** * Retrieves the ObjectFactory for the object identified by a reference, * using the reference's factory class name and factory codebase * to load in the factory's class. * @param ref The non-null reference to use. * @param factoryName The non-null class name of the factory. * @return The object factory for the object identified by ref; null * if unable to load the factory. */ static ObjectFactory getObjectFactoryFromReference( Reference ref, String factoryName) throws IllegalAccessException, InstantiationException, MalformedURLException { Class clas = null; // Try to use current class loader try { clas = helper.loadClass(factoryName); } catch (ClassNotFoundException e) { // ignore and continue // e.printStackTrace(); } // All other exceptions are passed up. // Not in class path; try to use codebase String codebase; if (clas == null && (codebase = ref.getFactoryClassLocation()) != null) { try { clas = helper.loadClass(factoryName, codebase); } catch (ClassNotFoundException e) { } } return (clas != null) ? (ObjectFactory) clas.newInstance() : null; } /** * Creates an object using the factories specified in the * Context.OBJECT_FACTORIES property of the environment * or of the provider resource file associated with nameCtx. * * @return factory created; null if cannot create */ private static Object createObjectFromFactories(Object obj, Name name, Context nameCtx, Hashtable environment) throws Exception { FactoryEnumeration factories = ResourceManager.getFactories( Context.OBJECT_FACTORIES, environment, nameCtx); if (factories == null) return null; // Try each factory until one succeeds ObjectFactory factory; Object answer = null; while (answer == null && factories.hasMore()) { factory = (ObjectFactory)factories.next(); answer = factory.getObjectInstance(obj, name, nameCtx, environment); } return answer; } private static String getURLScheme(String str) { int colon_posn = str.indexOf(':'); int slash_posn = str.indexOf('/'); if (colon_posn > 0 && (slash_posn == -1 || colon_posn < slash_posn)) return str.substring(0, colon_posn); return null; } /** * Creates an instance of an object for the specified object * and environment. *
* If an object factory builder has been installed, it is used to * create a factory for creating the object. * Otherwise, the following rules are used to create the object: *
refInfo is a Reference
* or Referenceable containing a factory class name,
* use the named factory to create the object.
* Return refInfo if the factory cannot be created.
* Under JDK 1.1, if the factory class must be loaded from a location
* specified in the reference, a SecurityManager must have
* been installed or the factory creation will fail.
* If an exception is encountered while creating the factory,
* it is passed up to the caller.
* refInfo.
* If an exception is encountered while creating the object, the
* exception is passed up to the caller.
** Service providers that implement the DirContext * interface should use * DirectoryManager.getObjectInstance(), not this method. * Service providers that implement only the Context * interface should use this method. *
* Note that an object factory (an object that implements the ObjectFactory * interface) must be public and must have a public constructor that * accepts no arguments. *
* The
* The resulting context is for resolving URLs of the
* scheme
* The class name of the factory that creates the resulting context
* has the naming convention scheme-idURLContextFactory
* (e.g. "ftpURLContextFactory" for the "ftp" scheme-id),
* in the package specified as follows.
* The Context.URL_PKG_PREFIXES environment property (which
* may contain values taken from applet parameters, system properties,
* or application resource files)
* contains a colon-separated list of package prefixes.
* Each package prefix in
* the property is tried in the order specified to load the factory class.
* The default package prefix is "com.sun.jndi.url" (if none of the
* specified packages work, this default is tried).
* The complete package name is constructed using the package prefix,
* concatenated with the scheme id.
*
* For example, if the scheme id is "ldap", and the
* Context.URL_PKG_PREFIXES property
* contains "com.widget:com.wiz.jndi",
* the naming manager would attempt to load the following classes
* until one is successfully instantiated:
*
* If a factory is instantiated, it is invoked with the following
* parameters to produce the resulting context.
*
*
* For example, invoking getObjectInstance() as shown above
* on a LDAP URL context factory would return a
* context that can resolve LDAP urls
* (e.g. "ldap://ldap.wiz.com/o=wiz,c=us",
* "ldap://ldap.umich.edu/o=umich,c=us", ...).
*
* Note that an object factory (an object that implements the ObjectFactory
* interface) must be public and must have a public constructor that
* accepts no arguments.
*
* @param scheme The non-null scheme-id of the URLs supported by the context.
* @param environment The possibly null environment properties to be
* used in the creation of the object factory and the context.
* @return A context for resolving URLs with the
* scheme id
* If urlInfo is null, the result is a context for resolving URLs
* with the scheme id 'scheme'.
* If urlInfo is a URL, the result is a context named by the URL.
* Names passed to this context is assumed to be relative to this
* context (i.e. not a URL). For example, if urlInfo is
* "ldap://ldap.wiz.com/o=Wiz,c=us", the resulting context will
* be that pointed to by "o=Wiz,c=us" on the server 'ldap.wiz.com'.
* Subsequent names that can be passed to this context will be
* LDAP names relative to this context (e.g. cn="Barbs Jensen").
* If urlInfo is an array of URLs, the URLs are assumed
* to be equivalent in terms of the context to which they refer.
* The resulting context is like that of the single URL case.
* If urlInfo is of any other type, that is handled by the
* context factory for the URL scheme.
* @param scheme the URL scheme id for the context
* @param urlInfo information used to create the context
* @param name name of this object relative to
* If an InitialContextFactoryBuilder has been installed,
* it is used to create the factory for creating the initial context.
* Otherwise, the class specified in the
* Context.INITIAL_CONTEXT_FACTORY environment property is used.
* Note that an initial context factory (an object that implements the
* InitialContextFactory interface) must be public and must have a
* public constructor that accepts no arguments.
*
* @param env The possibly null environment properties used when
* creating the context.
* @return A non-null initial context.
* @exception NoInitialContextException If the
* Context.INITIAL_CONTEXT_FACTORY property
* is not found or names a nonexistent
* class or a class that cannot be instantiated,
* or if the initial context could not be created for some other
* reason.
* @exception NamingException If some other naming exception was encountered.
* @see javax.naming.InitialContext
* @see javax.naming.directory.InitialDirContext
*/
public static Context getInitialContext(Hashtable env)
throws NamingException {
InitialContextFactory factory;
InitialContextFactoryBuilder builder = getInitialContextFactoryBuilder();
if (builder == null) {
// No factory installed, use property
// Get initial context factory class name
String className = env != null ?
(String)env.get(Context.INITIAL_CONTEXT_FACTORY) : null;
if (className == null) {
NoInitialContextException ne = new NoInitialContextException(
"Need to specify class name in environment or system " +
"property, or as an applet parameter, or in an " +
"application resource file: " +
Context.INITIAL_CONTEXT_FACTORY);
throw ne;
}
try {
factory = (InitialContextFactory)
helper.loadClass(className).newInstance();
} catch(Exception e) {
NoInitialContextException ne =
new NoInitialContextException(
"Cannot instantiate class: " + className);
ne.setRootCause(e);
throw ne;
}
} else {
factory = builder.createInitialContextFactory(env);
}
return factory.getInitialContext(env);
}
/**
* Sets the InitialContextFactory builder to be builder.
*
*
* The builder can only be installed if the executing thread is allowed by
* the security manager to do so. Once installed, the builder cannot
* be replaced.
* @param builder The initial context factory builder to install. If null,
* no builder is set.
* @exception SecurityException builder cannot be installed for security
* reasons.
* @exception NamingException builder cannot be installed for
* a non-security-related reason.
* @exception IllegalStateException If a builder was previous installed.
* @see #hasInitialContextFactoryBuilder
* @see java.lang.SecurityManager#checkSetFactory
*/
public static synchronized void setInitialContextFactoryBuilder(
InitialContextFactoryBuilder builder)
throws NamingException {
if (initctx_factory_builder != null)
throw new IllegalStateException(
"InitialContextFactoryBuilder already set");
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkSetFactory();
}
initctx_factory_builder = builder;
}
/**
* Determines whether an initial context factory builder has
* been set.
* @return true if an initial context factory builder has
* been set; false otherwise.
* @see #setInitialContextFactoryBuilder
*/
public static boolean hasInitialContextFactoryBuilder() {
return (getInitialContextFactoryBuilder() != null);
}
// ----- Continuation Context Stuff
/**
* Constant that holds the name of the environment property into
* which getContinuationContext() stores the value of its
* CannotProceedException parameter.
* This property is inherited by the continuation context, and may
* be used by that context's service provider to inspect the
* fields of the exception.
*
* The value of this constant is "java.naming.spi.CannotProceedException".
*
* @see #getContinuationContext
* @since 1.3
*/
public static final String CPE = "java.naming.spi.CannotProceedException";
/**
* Creates a context in which to continue a context operation.
*
* In performing an operation on a name that spans multiple
* namespaces, a context from one naming system may need to pass
* the operation on to the next naming system. The context
* implementation does this by first constructing a
*
* Before making use of the cpe parameter, this method
* updates the environment associated with that object by setting
* the value of the property CPE
* to cpe. This property will be inherited by the
* continuation context, and may be used by that context's
* service provider to inspect the fields of this exception.
*
* @param cpe
* The non-null exception that triggered this continuation.
* @return A non-null Context object for continuing the operation.
* @exception NamingException If a naming exception occurred.
*/
public static Context getContinuationContext(CannotProceedException cpe)
throws NamingException {
Hashtable env = cpe.getEnvironment();
if (env == null) {
env = new Hashtable(7);
} else {
// Make a (shallow) copy of the environment.
env = (Hashtable) env.clone();
}
env.put(CPE, cpe);
ContinuationContext cctx = new ContinuationContext(cpe, env);
return cctx.getTargetContext();
}
// ------------ State Factory Stuff
/**
* Retrieves the state of an object for binding.
*
* Service providers that implement the DirContext interface
* should use DirectoryManager.getStateToBind(), not this method.
* Service providers that implement only the Context interface
* should use this method.
*
* This method uses the specified state factories in
* the Context.STATE_FACTORIES property from the environment
* properties, and from the provider resource file associated with
* nameCtx, in that order.
* The value of this property is a colon-separated list of factory
* class names that are tried in order, and the first one that succeeds
* in returning the object's state is the one used.
* If no object's state can be retrieved in this way, return the
* object itself.
* If an exception is encountered while retrieving the state, the
* exception is passed up to the caller.
*
* Note that a state factory
* (an object that implements the StateFactory
* interface) must be public and must have a public constructor that
* accepts no arguments.
*
* The
* This method may return a Referenceable object. The
* service provider obtaining this object may choose to store it
* directly, or to extract its reference (using
* Referenceable.getReference()) and store that instead.
*
* @param obj The non-null object for which to get state to bind.
* @param name The name of this object relative to name and nameCtx parameters may
* optionally be used to specify the name of the object being created.
* name is the name of the object, relative to context
* nameCtx. This information could be useful to the object
* factory or to the object implementation.
* If there are several possible contexts from which the object
* could be named -- as will often be the case -- it is up to
* the caller to select one. A good rule of thumb is to select the
* "deepest" context available.
* If nameCtx is null, name is relative
* to the default initial context. If no name is being specified, the
* name parameter should be null.
*
* @param refInfo The possibly null object for which to create an object.
* @param name The name of this object relative to nameCtx.
* Specifying a name is optional; if it is
* omitted, name should be null.
* @param nameCtx The context relative to which the name
* parameter is specified. If null, name is
* relative to the default initial context.
* @param environment The possibly null environment to
* be used in the creation of the object factory and the object.
* @return An object created using refInfo; or
* refInfo if an object cannot be created using
* the algorithm described above.
* @exception NamingException if a naming exception was encountered
* while attempting to get a URL context, or if one of the
* factories accessed throws a NamingException.
* @exception Exception if one of the factories accessed throws an
* exception, or if an error was encountered while loading
* and instantiating the factory and object classes.
* A factory should only throw an exception if it does not want
* other factories to be used in an attempt to create an object.
* See ObjectFactory.getObjectInstance().
* @see #getURLContext
* @see ObjectFactory
* @see ObjectFactory#getObjectInstance
*/
public static Object
getObjectInstance(Object refInfo, Name name, Context nameCtx,
Hashtable environment)
throws Exception
{
ObjectFactory factory;
// Use builder if installed
ObjectFactoryBuilder builder = getObjectFactoryBuilder();
if (builder != null) {
// builder must return non-null factory
factory = builder.createObjectFactory(refInfo, environment);
return factory.getObjectInstance(refInfo, name, nameCtx,
environment);
}
// Use reference if possible
Reference ref = null;
if (refInfo instanceof Reference) {
ref = (Reference) refInfo;
} else if (refInfo instanceof Referenceable) {
ref = ((Referenceable)(refInfo)).getReference();
}
Object answer;
if (ref != null) {
String f = ref.getFactoryClassName();
if (f != null) {
// if reference identifies a factory, use exclusively
factory = getObjectFactoryFromReference(ref, f);
if (factory != null) {
return factory.getObjectInstance(ref, name, nameCtx,
environment);
}
// No factory found, so return original refInfo.
// Will reach this point if factory class is not in
// class path and reference does not contain a URL for it
return refInfo;
} else {
// if reference has no factory, check for addresses
// containing URLs
answer = processURLAddrs(ref, name, nameCtx, environment);
if (answer != null) {
return answer;
}
}
}
// try using any specified factories
answer =
createObjectFromFactories(refInfo, name, nameCtx, environment);
return (answer != null) ? answer : refInfo;
}
/*
* Ref has no factory. For each address of type "URL", try its URL
* context factory. Returns null if unsuccessful in creating and
* invoking a factory.
*/
static Object processURLAddrs(Reference ref, Name name, Context nameCtx,
Hashtable environment)
throws NamingException {
for (int i = 0; i < ref.size(); i++) {
RefAddr addr = ref.get(i);
if (addr instanceof StringRefAddr &&
addr.getType().equalsIgnoreCase("URL")) {
String url = (String)addr.getContent();
Object answer = processURL(url, name, nameCtx, environment);
if (answer != null) {
return answer;
}
}
}
return null;
}
private static Object processURL(Object refInfo, Name name,
Context nameCtx, Hashtable environment)
throws NamingException {
Object answer;
// If refInfo is a URL string, try to use its URL context factory
// If no context found, continue to try object factories.
if (refInfo instanceof String) {
String url = (String)refInfo;
String scheme = getURLScheme(url);
if (scheme != null) {
answer = getURLObject(scheme, refInfo, name, nameCtx,
environment);
if (answer != null) {
return answer;
}
}
}
// If refInfo is an array of URL strings,
// try to find a context factory for any one of its URLs.
// If no context found, continue to try object factories.
if (refInfo instanceof String[]) {
String[] urls = (String[])refInfo;
for (int i = 0; i nameCtx, or null if no name is being
* specified.
* See the getObjectInstance method for
* details.
* @param ctx The context relative to which name is
* specified, or null for the default initial context.
* See the getObjectInstance method for
* details.
* @param environment Environment specifying characteristics of the
* resulting context.
* @return A context identified by obj.
*
* @see #getObjectInstance
*/
static Context getContext(Object obj, Name name, Context nameCtx,
Hashtable environment) throws NamingException {
Object answer;
if (obj instanceof Context) {
// %%% Ignore environment for now. OK since method not public.
return (Context)obj;
}
try {
answer = getObjectInstance(obj, name, nameCtx, environment);
} catch (NamingException e) {
throw e;
} catch (Exception e) {
NamingException ne = new NamingException();
ne.setRootCause(e);
throw ne;
}
return (answer instanceof Context)
? (Context)answer
: null;
}
// Used by ContinuationContext
static Resolver getResolver(Object obj, Name name, Context nameCtx,
Hashtable environment) throws NamingException {
Object answer;
if (obj instanceof Resolver) {
// %%% Ignore environment for now. OK since method not public.
return (Resolver)obj;
}
try {
answer = getObjectInstance(obj, name, nameCtx, environment);
} catch (NamingException e) {
throw e;
} catch (Exception e) {
NamingException ne = new NamingException();
ne.setRootCause(e);
throw ne;
}
return (answer instanceof Resolver)
? (Resolver)answer
: null;
}
/***************** URL Context implementations ***************/
/**
* Creates a context for the given URL scheme id.
* scheme. The resulting context is not tied
* to a specific URL. It is able to handle arbitrary URLs with
* the specified scheme.
*
*
* If none of the package prefixes work, null is returned.
*factory.getObjectInstance(null, environment);
* scheme;
* null if the factory for creating the
* context is not found.
* @exception NamingException If a naming exception occurs while creating
* the context.
* @see #getObjectInstance
* @see ObjectFactory#getObjectInstance
*/
public static Context getURLContext(String scheme,
Hashtable environment)
throws NamingException
{
// pass in 'null' to indicate creation of generic context for scheme
// (i.e. not specific to a URL).
Object answer = getURLObject(scheme, null, null, null, environment);
if (answer instanceof Context) {
return (Context)answer;
} else {
return null;
}
}
private static final String defaultPkgPrefix = "com.sun.jndi.url";
/**
* Creates an object for the given URL scheme id using
* the supplied urlInfo.
* nameCtx
* @param nameCtx Context whose provider resource file will be searched
* for package prefix values (or null if none)
* @param environment Environment properties for creating the context
* @see javax.naming.InitialContext
*/
private static Object getURLObject(String scheme, Object urlInfo,
Name name, Context nameCtx,
Hashtable environment)
throws NamingException {
// e.g. "ftpURLContextFactory"
ObjectFactory factory = (ObjectFactory)ResourceManager.getFactory(
Context.URL_PKG_PREFIXES, environment, nameCtx,
"." + scheme + "." + scheme + "URLContextFactory", defaultPkgPrefix);
if (factory == null)
return null;
// Found object factory
try {
return factory.getObjectInstance(urlInfo, name, nameCtx, environment);
} catch (NamingException e) {
throw e;
} catch (Exception e) {
NamingException ne = new NamingException();
ne.setRootCause(e);
throw ne;
}
}
// ------------ Initial Context Factory Stuff
private static InitialContextFactoryBuilder initctx_factory_builder = null;
/**
* Use this method for accessing initctx_factory_builder while
* inside an unsynchronized method.
*/
private static synchronized InitialContextFactoryBuilder
getInitialContextFactoryBuilder() {
return initctx_factory_builder;
}
/**
* Creates an initial context using the specified environment
* properties.
*CannotProceedException containing information
* pinpointing how far it has proceeded. It then obtains a
* continuation context from JNDI by calling
* getContinuationContext. The context
* implementation should then resume the context operation by
* invoking the same operation on the continuation context, using
* the remainder of the name that has not yet been resolved.
*name and nameCtx parameters may
* optionally be used to specify the name of the object being created.
* See the description of "Name and Context Parameters" in
* {@link ObjectFactory#getObjectInstance
* ObjectFactory.getObjectInstance()}
* for details.
* nameCtx,
* or null if no name is specified.
* @param nameCtx The context relative to which the name
* parameter is specified, or null if name is
* relative to the default initial context.
* @param environment The possibly null environment to
* be used in the creation of the state factory and
* the object's state.
* @return The non-null object representing obj's state for
* binding. It could be the object (obj) itself.
* @exception NamingException If one of the factories accessed throws an
* exception, or if an error was encountered while loading
* and instantiating the factory and object classes.
* A factory should only throw an exception if it does not want
* other factories to be used in an attempt to create an object.
* See StateFactory.getStateToBind().
* @see StateFactory
* @see StateFactory#getStateToBind
* @see DirectoryManager#getStateToBind
* @since 1.3
*/
public static Object
getStateToBind(Object obj, Name name, Context nameCtx,
Hashtable environment)
throws NamingException
{
FactoryEnumeration factories = ResourceManager.getFactories(
Context.STATE_FACTORIES, environment, nameCtx);
if (factories == null) {
return obj;
}
// Try each factory until one succeeds
StateFactory factory;
Object answer = null;
while (answer == null && factories.hasMore()) {
factory = (StateFactory)factories.next();
answer = factory.getStateToBind(obj, name, nameCtx, environment);
}
return (answer != null) ? answer : obj;
}
}