< prev index next >

src/java.naming/share/classes/javax/naming/spi/ObjectFactory.java

Print this page

        

*** 37,55 **** * For example, when looking up a printer bound in the name space, * if the print service binds printer names to References, the printer * Reference could be used to create a printer object, so that * the caller of lookup can directly operate on the printer object * after the lookup. ! * <p>An <tt>ObjectFactory</tt> is responsible * for creating objects of a specific type. In the above example, * you may have a PrinterObjectFactory for creating Printer objects. *<p> ! * An object factory must implement the <tt>ObjectFactory</tt> interface. * In addition, the factory class must be public and must have a * public constructor that accepts no parameters. *<p> ! * The <tt>getObjectInstance()</tt> method of an object factory may * be invoked multiple times, possibly using different parameters. * The implementation is thread-safe. *<p> * 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 --- 37,55 ---- * For example, when looking up a printer bound in the name space, * if the print service binds printer names to References, the printer * Reference could be used to create a printer object, so that * the caller of lookup can directly operate on the printer object * after the lookup. ! * <p>An {@code ObjectFactory} is responsible * for creating objects of a specific type. In the above example, * you may have a PrinterObjectFactory for creating Printer objects. *<p> ! * An object factory must implement the {@code ObjectFactory} interface. * In addition, the factory class must be public and must have a * public constructor that accepts no parameters. *<p> ! * The {@code getObjectInstance()} method of an object factory may * be invoked multiple times, possibly using different parameters. * The implementation is thread-safe. *<p> * 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
*** 71,163 **** /** * Creates an object using the location or reference information * specified. * <p> * Special requirements of this object are supplied ! * using <code>environment</code>. * An example of such an environment property is user identity * information. *<p> ! * <tt>NamingManager.getObjectInstance()</tt> * successively loads in object factories and invokes this method * on them until one produces a non-null answer. When an exception * is thrown by an object factory, the exception is passed on to the caller ! * of <tt>NamingManager.getObjectInstance()</tt> * (and no search is made for other factories * that may produce a non-null answer). * An object factory should only throw an exception if it is sure that * it is the only intended factory and that no other object factories * should be tried. * If this factory cannot create an object using the arguments supplied, * it should return null. *<p> * A <em>URL context factory</em> is a special ObjectFactory that * creates contexts for resolving URLs or objects whose locations ! * are specified by URLs. The <tt>getObjectInstance()</tt> method * of a URL context factory will obey the following rules. * <ol> ! * <li>If <code>obj</code> is null, create a context for resolving URLs of the * scheme associated with this factory. The resulting context is not tied * to a specific URL: it is able to handle arbitrary URLs with this factory's ! * scheme id. For example, invoking <tt>getObjectInstance()</tt> with ! * <code>obj</code> set to null on an LDAP URL context factory would return a * context that can resolve LDAP URLs * such as "ldap://ldap.wiz.com/o=wiz,c=us" and * "ldap://ldap.umich.edu/o=umich,c=us". * <li> ! * If <code>obj</code> is a URL string, create an object (typically a context) * identified by the URL. For example, suppose this is an LDAP URL context ! * factory. If <code>obj</code> is "ldap://ldap.wiz.com/o=wiz,c=us", * getObjectInstance() would return the context named by the distinguished * name "o=wiz, c=us" at the LDAP server ldap.wiz.com. This context can * then be used to resolve LDAP names (such as "cn=George") * relative to that context. * <li> ! * If <code>obj</code> is an array of URL strings, the assumption is that the * URLs are equivalent in terms of the context to which they refer. * Verification of whether the URLs are, or need to be, equivalent is up * to the context factory. The order of the URLs in the array is * not significant. * The object returned by getObjectInstance() is like that of the single * URL case. It is the object named by the URLs. * <li> ! * If <code>obj</code> is of any other type, the behavior of ! * <tt>getObjectInstance()</tt> is determined by the context factory * implementation. * </ol> * * <p> ! * The <tt>name</tt> and <tt>environment</tt> parameters * are owned by the caller. * The implementation will not modify these objects or keep references * to them, although it may keep references to clones or copies. * * <p> * <b>Name and Context Parameters.</b> &nbsp;&nbsp;&nbsp; * <a name=NAMECTX></a> * ! * The <code>name</code> and <code>nameCtx</code> parameters may * optionally be used to specify the name of the object being created. ! * <code>name</code> is the name of the object, relative to context ! * <code>nameCtx</code>. * 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 <code>nameCtx</code> is null, <code>name</code> is relative * to the default initial context. If no name is being specified, the ! * <code>name</code> parameter should be null. ! * If a factory uses <code>nameCtx</code> it should synchronize its use * against concurrent access, since context implementations are not * guaranteed to be thread-safe. * * @param obj The possibly null object containing location or reference * information that can be used in creating an object. ! * @param name The name of this object relative to <code>nameCtx</code>, * or null if no name is specified. ! * @param nameCtx The context relative to which the <code>name</code> ! * parameter is specified, or null if <code>name</code> is * relative to the default initial context. * @param environment The possibly null environment that is used in * creating the object. * @return The object created; null if an object cannot be created. * @exception Exception if this object factory encountered an exception --- 71,163 ---- /** * Creates an object using the location or reference information * specified. * <p> * Special requirements of this object are supplied ! * using {@code environment}. * An example of such an environment property is user identity * information. *<p> ! * {@code NamingManager.getObjectInstance()} * successively loads in object factories and invokes this method * on them until one produces a non-null answer. When an exception * is thrown by an object factory, the exception is passed on to the caller ! * of {@code NamingManager.getObjectInstance()} * (and no search is made for other factories * that may produce a non-null answer). * An object factory should only throw an exception if it is sure that * it is the only intended factory and that no other object factories * should be tried. * If this factory cannot create an object using the arguments supplied, * it should return null. *<p> * A <em>URL context factory</em> is a special ObjectFactory that * creates contexts for resolving URLs or objects whose locations ! * are specified by URLs. The {@code getObjectInstance()} method * of a URL context factory will obey the following rules. * <ol> ! * <li>If {@code obj} is null, create a context for resolving URLs of the * scheme associated with this factory. The resulting context is not tied * to a specific URL: it is able to handle arbitrary URLs with this factory's ! * scheme id. For example, invoking {@code getObjectInstance()} with ! * {@code obj} set to null on an LDAP URL context factory would return a * context that can resolve LDAP URLs * such as "ldap://ldap.wiz.com/o=wiz,c=us" and * "ldap://ldap.umich.edu/o=umich,c=us". * <li> ! * If {@code obj} is a URL string, create an object (typically a context) * identified by the URL. For example, suppose this is an LDAP URL context ! * factory. If {@code obj} is "ldap://ldap.wiz.com/o=wiz,c=us", * getObjectInstance() would return the context named by the distinguished * name "o=wiz, c=us" at the LDAP server ldap.wiz.com. This context can * then be used to resolve LDAP names (such as "cn=George") * relative to that context. * <li> ! * If {@code obj} is an array of URL strings, the assumption is that the * URLs are equivalent in terms of the context to which they refer. * Verification of whether the URLs are, or need to be, equivalent is up * to the context factory. The order of the URLs in the array is * not significant. * The object returned by getObjectInstance() is like that of the single * URL case. It is the object named by the URLs. * <li> ! * If {@code obj} is of any other type, the behavior of ! * {@code getObjectInstance()} is determined by the context factory * implementation. * </ol> * * <p> ! * The {@code name} and {@code environment} parameters * are owned by the caller. * The implementation will not modify these objects or keep references * to them, although it may keep references to clones or copies. * * <p> * <b>Name and Context Parameters.</b> &nbsp;&nbsp;&nbsp; * <a name=NAMECTX></a> * ! * The {@code name} and {@code nameCtx} parameters may * optionally be used to specify the name of the object being created. ! * {@code name} is the name of the object, relative to context ! * {@code nameCtx}. * 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 {@code nameCtx} is null, {@code name} is relative * to the default initial context. If no name is being specified, the ! * {@code name} parameter should be null. ! * If a factory uses {@code nameCtx} it should synchronize its use * against concurrent access, since context implementations are not * guaranteed to be thread-safe. * * @param obj The possibly null object containing location or reference * information that can be used in creating an object. ! * @param name The name of this object relative to {@code nameCtx}, * or null if no name is specified. ! * @param nameCtx The context relative to which the {@code name} ! * parameter is specified, or null if {@code name} is * relative to the default initial context. * @param environment The possibly null environment that is used in * creating the object. * @return The object created; null if an object cannot be created. * @exception Exception if this object factory encountered an exception
< prev index next >