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Java Standard Edition (SE)

InitialContext


compact3
javax.naming

Class InitialContext

  • All Implemented Interfaces:
    Context
    Direct Known Subclasses:
    InitialDirContext


    public class InitialContext
    extends Object
    implements Context
    This class is the starting context for performing naming operations.

    All naming operations are relative to a context. The initial context implements the Context interface and provides the starting point for resolution of names.

    When the initial context is constructed, its environment is initialized with properties defined in the environment parameter passed to the constructor, and in any application resource files. In addition, a small number of standard JNDI properties may be specified as system properties or as applet parameters (through the use of Context.APPLET). These special properties are listed in the field detail sections of the Context and LdapContext interface documentation.

    JNDI determines each property's value by merging the values from the following two sources, in order:

    1. The first occurrence of the property from the constructor's environment parameter and (for appropriate properties) the applet parameters and system properties.
    2. The application resource files (jndi.properties).
    For each property found in both of these two sources, or in more than one application resource file, the property's value is determined as follows. If the property is one of the standard JNDI properties that specify a list of JNDI factories (see Context), all of the values are concatenated into a single colon-separated list. For other properties, only the first value found is used.

    The initial context implementation is determined at runtime. The default policy uses the environment property "java.naming.factory.initial", which contains the class name of the initial context factory. An exception to this policy is made when resolving URL strings, as described below.

    When a URL string (a String of the form scheme_id:rest_of_name) is passed as a name parameter to any method, a URL context factory for handling that scheme is located and used to resolve the URL. If no such factory is found, the initial context specified by "java.naming.factory.initial" is used. Similarly, when a CompositeName object whose first component is a URL string is passed as a name parameter to any method, a URL context factory is located and used to resolve the first name component. See NamingManager.getURLContext() for a description of how URL context factories are located.

    This default policy of locating the initial context and URL context factories may be overridden by calling NamingManager.setInitialContextFactoryBuilder().

    NoInitialContextException is thrown when an initial context cannot be instantiated. This exception can be thrown during any interaction with the InitialContext, not only when the InitialContext is constructed. For example, the implementation of the initial context might lazily retrieve the context only when actual methods are invoked on it. The application should not have any dependency on when the existence of an initial context is determined.

    When the environment property "java.naming.factory.initial" is non-null, the InitialContext constructor will attempt to create the initial context specified therein. At that time, the initial context factory involved might throw an exception if a problem is encountered. However, it is provider implementation-dependent when it verifies and indicates to the users of the initial context any environment property- or connection- related problems. It can do so lazily--delaying until an operation is performed on the context, or eagerly, at the time the context is constructed.

    An InitialContext instance is not synchronized against concurrent access by multiple threads. Multiple threads each manipulating a different InitialContext instance need not synchronize. Threads that need to access a single InitialContext instance concurrently should synchronize amongst themselves and provide the necessary locking.

    Since:
    JNDI 1.1 / Java 2 Platform, Standard Edition, v 1.3
    See Also:
    Context, NamingManager.setInitialContextFactoryBuilder
    • Field Detail

      • defaultInitCtx

        protected Context defaultInitCtx
        Field holding the result of calling NamingManager.getInitialContext(). It is set by getDefaultInitCtx() the first time getDefaultInitCtx() is called. Subsequent invocations of getDefaultInitCtx() return the value of defaultInitCtx.
        See Also:
        getDefaultInitCtx()
      • gotDefault

        protected boolean gotDefault
        Field indicating whether the initial context has been obtained by calling NamingManager.getInitialContext(). If true, its result is in defaultInitCtx.
    • Constructor Detail

      • InitialContext

        protected InitialContext(boolean lazy)
                          throws NamingException
        Constructs an initial context with the option of not initializing it. This may be used by a constructor in a subclass when the value of the environment parameter is not yet known at the time the InitialContext constructor is called. The subclass's constructor will call this constructor, compute the value of the environment, and then call init() before returning.
        Parameters:
        lazy - true means do not initialize the initial context; false is equivalent to calling new InitialContext()
        Throws:
        NamingException - if a naming exception is encountered
        Since:
        1.3
        See Also:
        init(Hashtable)
      • InitialContext

        public InitialContext(Hashtable<?,?> environment)
                       throws NamingException
        Constructs an initial context using the supplied environment. Environment properties are discussed in the class description.

        This constructor will not modify environment or save a reference to it, but may save a clone. Caller should not modify mutable keys and values in environment after it has been passed to the constructor.

        Parameters:
        environment - environment used to create the initial context. Null indicates an empty environment.
        Throws:
        NamingException - if a naming exception is encountered
    • Method Detail

      • init

        protected void init(Hashtable<?,?> environment)
                     throws NamingException
        Initializes the initial context using the supplied environment. Environment properties are discussed in the class description.

        This method will modify environment and save a reference to it. The caller may no longer modify it.

        Parameters:
        environment - environment used to create the initial context. Null indicates an empty environment.
        Throws:
        NamingException - if a naming exception is encountered
        Since:
        1.3
        See Also:
        InitialContext(boolean)
      • doLookup

        public static <T> T doLookup(Name name)
                              throws NamingException
        A static method to retrieve the named object. This is a shortcut method equivalent to invoking:

        InitialContext ic = new InitialContext(); Object obj = ic.lookup();

        If name is empty, returns a new instance of this context (which represents the same naming context as this context, but its environment may be modified independently and it may be accessed concurrently).

        Type Parameters:
        T - the type of the returned object
        Parameters:
        name - the name of the object to look up
        Returns:
        the object bound to name
        Throws:
        NamingException - if a naming exception is encountered
        Since:
        1.6
        See Also:
        doLookup(String), lookup(Name)
      • doLookup

        public static <T> T doLookup(String name)
                              throws NamingException
        A static method to retrieve the named object. See doLookup(Name) for details.
        Type Parameters:
        T - the type of the returned object
        Parameters:
        name - the name of the object to look up
        Returns:
        the object bound to name
        Throws:
        NamingException - if a naming exception is encountered
        Since:
        1.6
      • getDefaultInitCtx

        protected Context getDefaultInitCtx()
                                     throws NamingException
        Retrieves the initial context by calling NamingManager.getInitialContext() and cache it in defaultInitCtx. Set gotDefault so that we know we've tried this before.
        Returns:
        The non-null cached initial context.
        Throws:
        NoInitialContextException - If cannot find an initial context.
        NamingException - If a naming exception was encountered.
      • getURLOrDefaultInitCtx

        protected Context getURLOrDefaultInitCtx(String name)
                                          throws NamingException
        Retrieves a context for resolving the string name name. If name name is a URL string, then attempt to find a URL context for it. If none is found, or if name is not a URL string, then return getDefaultInitCtx().

        See getURLOrDefaultInitCtx(Name) for description of how a subclass should use this method.

        Parameters:
        name - The non-null name for which to get the context.
        Returns:
        A URL context for name or the cached initial context. The result cannot be null.
        Throws:
        NoInitialContextException - If cannot find an initial context.
        NamingException - In a naming exception is encountered.
        See Also:
        NamingManager.getURLContext(java.lang.String, java.util.Hashtable<?, ?>)
      • getURLOrDefaultInitCtx

        protected Context getURLOrDefaultInitCtx(Name name)
                                          throws NamingException
        Retrieves a context for resolving name. If the first component of name name is a URL string, then attempt to find a URL context for it. If none is found, or if the first component of name is not a URL string, then return getDefaultInitCtx().

        When creating a subclass of InitialContext, use this method as follows. Define a new method that uses this method to get an initial context of the desired subclass.

         protected XXXContext getURLOrDefaultInitXXXCtx(Name name)
         throws NamingException {
          Context answer = getURLOrDefaultInitCtx(name);
          if (!(answer instanceof XXXContext)) {
            if (answer == null) {
              throw new NoInitialContextException();
            } else {
              throw new NotContextException("Not an XXXContext");
            }
          }
          return (XXXContext)answer;
         }
         
        When providing implementations for the new methods in the subclass, use this newly defined method to get the initial context.
         public Object XXXMethod1(Name name, ...) {
          throws NamingException {
            return getURLOrDefaultInitXXXCtx(name).XXXMethod1(name, ...);
         }
         
        Parameters:
        name - The non-null name for which to get the context.
        Returns:
        A URL context for name or the cached initial context. The result cannot be null.
        Throws:
        NoInitialContextException - If cannot find an initial context.
        NamingException - In a naming exception is encountered.
        See Also:
        NamingManager.getURLContext(java.lang.String, java.util.Hashtable<?, ?>)
      • lookup

        public Object lookup(Name name)
                      throws NamingException
        Description copied from interface: Context
        Retrieves the named object. If name is empty, returns a new instance of this context (which represents the same naming context as this context, but its environment may be modified independently and it may be accessed concurrently).
        Specified by:
        lookup in interface Context
        Parameters:
        name - the name of the object to look up
        Returns:
        the object bound to name
        Throws:
        NamingException - if a naming exception is encountered
        See Also:
        Context.lookup(String), Context.lookupLink(Name)
      • unbind

        public void unbind(Name name)
                    throws NamingException
        Description copied from interface: Context
        Unbinds the named object. Removes the terminal atomic name in name from the target context--that named by all but the terminal atomic part of name.

        This method is idempotent. It succeeds even if the terminal atomic name is not bound in the target context, but throws NameNotFoundException if any of the intermediate contexts do not exist.

        Any attributes associated with the name are removed. Intermediate contexts are not changed.

        Specified by:
        unbind in interface Context
        Parameters:
        name - the name to unbind; may not be empty
        Throws:
        NameNotFoundException - if an intermediate context does not exist
        NamingException - if a naming exception is encountered
        See Also:
        Context.unbind(String)
      • list

        public NamingEnumeration<NameClassPair> list(String name)
                                              throws NamingException
        Description copied from interface: Context
        Enumerates the names bound in the named context, along with the class names of objects bound to them. See Context.list(Name) for details.
        Specified by:
        list in interface Context
        Parameters:
        name - the name of the context to list
        Returns:
        an enumeration of the names and class names of the bindings in this context. Each element of the enumeration is of type NameClassPair.
        Throws:
        NamingException - if a naming exception is encountered
      • list

        public NamingEnumeration<NameClassPair> list(Name name)
                                              throws NamingException
        Description copied from interface: Context
        Enumerates the names bound in the named context, along with the class names of objects bound to them. The contents of any subcontexts are not included.

        If a binding is added to or removed from this context, its effect on an enumeration previously returned is undefined.

        Specified by:
        list in interface Context
        Parameters:
        name - the name of the context to list
        Returns:
        an enumeration of the names and class names of the bindings in this context. Each element of the enumeration is of type NameClassPair.
        Throws:
        NamingException - if a naming exception is encountered
        See Also:
        Context.list(String), Context.listBindings(Name), NameClassPair
      • listBindings

        public NamingEnumeration<Binding> listBindings(Name name)
                                                throws NamingException
        Description copied from interface: Context
        Enumerates the names bound in the named context, along with the objects bound to them. The contents of any subcontexts are not included.

        If a binding is added to or removed from this context, its effect on an enumeration previously returned is undefined.

        Specified by:
        listBindings in interface Context
        Parameters:
        name - the name of the context to list
        Returns:
        an enumeration of the bindings in this context. Each element of the enumeration is of type Binding.
        Throws:
        NamingException - if a naming exception is encountered
        See Also:
        Context.listBindings(String), Context.list(Name), Binding
      • destroySubcontext

        public void destroySubcontext(Name name)
                               throws NamingException
        Description copied from interface: Context
        Destroys the named context and removes it from the namespace. Any attributes associated with the name are also removed. Intermediate contexts are not destroyed.

        This method is idempotent. It succeeds even if the terminal atomic name is not bound in the target context, but throws NameNotFoundException if any of the intermediate contexts do not exist.

        In a federated naming system, a context from one naming system may be bound to a name in another. One can subsequently look up and perform operations on the foreign context using a composite name. However, an attempt destroy the context using this composite name will fail with NotContextException, because the foreign context is not a "subcontext" of the context in which it is bound. Instead, use unbind() to remove the binding of the foreign context. Destroying the foreign context requires that the destroySubcontext() be performed on a context from the foreign context's "native" naming system.

        Specified by:
        destroySubcontext in interface Context
        Parameters:
        name - the name of the context to be destroyed; may not be empty
        Throws:
        NameNotFoundException - if an intermediate context does not exist
        NotContextException - if the name is bound but does not name a context, or does not name a context of the appropriate type
        ContextNotEmptyException - if the named context is not empty
        NamingException - if a naming exception is encountered
        See Also:
        Context.destroySubcontext(String)
      • lookupLink

        public Object lookupLink(String name)
                          throws NamingException
        Description copied from interface: Context
        Retrieves the named object, following links except for the terminal atomic component of the name. See Context.lookupLink(Name) for details.
        Specified by:
        lookupLink in interface Context
        Parameters:
        name - the name of the object to look up
        Returns:
        the object bound to name, not following the terminal link (if any)
        Throws:
        NamingException - if a naming exception is encountered
      • lookupLink

        public Object lookupLink(Name name)
                          throws NamingException
        Description copied from interface: Context
        Retrieves the named object, following links except for the terminal atomic component of the name. If the object bound to name is not a link, returns the object itself.
        Specified by:
        lookupLink in interface Context
        Parameters:
        name - the name of the object to look up
        Returns:
        the object bound to name, not following the terminal link (if any).
        Throws:
        NamingException - if a naming exception is encountered
        See Also:
        Context.lookupLink(String)
      • getNameParser

        public NameParser getNameParser(Name name)
                                 throws NamingException
        Description copied from interface: Context
        Retrieves the parser associated with the named context. In a federation of namespaces, different naming systems will parse names differently. This method allows an application to get a parser for parsing names into their atomic components using the naming convention of a particular naming system. Within any single naming system, NameParser objects returned by this method must be equal (using the equals() test).
        Specified by:
        getNameParser in interface Context
        Parameters:
        name - the name of the context from which to get the parser
        Returns:
        a name parser that can parse compound names into their atomic components
        Throws:
        NamingException - if a naming exception is encountered
        See Also:
        Context.getNameParser(String), CompoundName
      • composeName

        public String composeName(String name,
                                  String prefix)
                           throws NamingException
        Composes the name of this context with a name relative to this context. Since an initial context may never be named relative to any context other than itself, the value of the prefix parameter must be an empty name ("").
        Specified by:
        composeName in interface Context
        Parameters:
        name - a name relative to this context
        prefix - the name of this context relative to one of its ancestors
        Returns:
        the composition of prefix and name
        Throws:
        NamingException - if a naming exception is encountered
      • composeName

        public Name composeName(Name name,
                                Name prefix)
                         throws NamingException
        Composes the name of this context with a name relative to this context. Since an initial context may never be named relative to any context other than itself, the value of the prefix parameter must be an empty name.
        Specified by:
        composeName in interface Context
        Parameters:
        name - a name relative to this context
        prefix - the name of this context relative to one of its ancestors
        Returns:
        the composition of prefix and name
        Throws:
        NamingException - if a naming exception is encountered
        See Also:
        Context.composeName(String, String)
      • addToEnvironment

        public Object addToEnvironment(String propName,
                                       Object propVal)
                                throws NamingException
        Description copied from interface: Context
        Adds a new environment property to the environment of this context. If the property already exists, its value is overwritten. See class description for more details on environment properties.
        Specified by:
        addToEnvironment in interface Context
        Parameters:
        propName - the name of the environment property to add; may not be null
        propVal - the value of the property to add; may not be null
        Returns:
        the previous value of the property, or null if the property was not in the environment before
        Throws:
        NamingException - if a naming exception is encountered
        See Also:
        Context.getEnvironment(), Context.removeFromEnvironment(String)
      • close

        public void close()
                   throws NamingException
        Description copied from interface: Context
        Closes this context. This method releases this context's resources immediately, instead of waiting for them to be released automatically by the garbage collector.

        This method is idempotent: invoking it on a context that has already been closed has no effect. Invoking any other method on a closed context is not allowed, and results in undefined behaviour.

        Specified by:
        close in interface Context
        Throws:
        NamingException - if a naming exception is encountered
      • getNameInNamespace

        public String getNameInNamespace()
                                  throws NamingException
        Description copied from interface: Context
        Retrieves the full name of this context within its own namespace.

        Many naming services have a notion of a "full name" for objects in their respective namespaces. For example, an LDAP entry has a distinguished name, and a DNS record has a fully qualified name. This method allows the client application to retrieve this name. The string returned by this method is not a JNDI composite name and should not be passed directly to context methods. In naming systems for which the notion of full name does not make sense, OperationNotSupportedException is thrown.

        Specified by:
        getNameInNamespace in interface Context
        Returns:
        this context's name in its own namespace; never null
        Throws:
        OperationNotSupportedException - if the naming system does not have the notion of a full name
        NamingException - if a naming exception is encountered


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