2.6 NetWare File System Provider
2.6.1 Introduction
The NetWare File System Provider for JNDI provides contexts that represent objects in the file system, such as NetWare volumes, directories and files. It also describes how to access file streams, create and delete files, and access attributes of the file system.
2.6.2 File System Provider Components
The components (interfaces and classes) of the NetWare File System are contained in two packages:
- Package com.novell.java.io provides functionality for file I/O, including file streams access.
- Package com.novell.java.file.nw provides access to all other file system functionality.
The com.novell.java.io streams components are extended in the com.novell.service.file.nw package to provide NetWare specific extensions of the various streams interfaces.
The most important interfaces and classes in these packages are described below. All components of each package may be accessed by going to the links provided above.
- com.novell.service.file.nw.NameSpace class provides an interface for getting the default name space for the platform on which the JVM is executing. It also provides a central interface for changing NetWare file system name space integer values into strings and vice versa.
- com.novell.java.io.NFile interface has been defined in terms of the java.io.File interface. Instances of the NFile class represent the name of a file or directory on the host file system. This class is intended to provide an abstraction that deals with most of the machine dependent complexities of files and path names in a machine-independent fashion.
- com.novell.service.file.nw.NetwareFile interface is used for getting the NetWare file system file object attribute values, which include Directory Entry Information, Extended Attributes, Effective Rights, and Trustees.
- com.novell.service.file.nw.DirectoryEntryInformation class results in a mutable object, and provides the NetWareFile interface with 26 attribute values of Directory Entry Information. A directory entry can be a file or a directory.
- com.novell.service.file.nw.EffectiveRights class provides an attribute interface for effective rights of a file or directory. It contains information about the effective rights for a users name for which to return effective rights and the rights for the currently logged or requested user.
- com.novell.service.file.nw.ExtendedAttribute class provides constructors and methods for the support of an extended attribute, which is a name and a corresponding byte array of data associated with a given file. The given file can have multiple extended attributes, which can be enumerated using the EAEnumerator interface.
- com.novell.service.file.nw.EAEnumerator interface provides for enumeration of extended attributes of a given file, which can have multiple extended attributes.
- com.novell.service.file.nw.Trustee class provides variables, constructors and methods for the support of a trustee, which is composed of a name identifying the trustee, the rights associated with the named trustee and a compare string. Trustees can be associated with a given directory entry (file or directory), which can have multiple trustees that may be enumerated using the TrusteeEnumerator interface.
- com.novell.service.file.nw.TrusteeEnumerator interface provides for enumeration of trustees of a given directory entry (file or directory), which can have multiple trustees.
- com.novell.service.file.nw.TrusteePathEnumerator interface provides an attribute for enumeration of all paths on a volume to which a user is assigned as a trustee. This interface contains the user name for which to return trustee paths, and the paths for the currently logged or requested user.
- com.novell.service.file.nw.NetwareDirectory interface is used for getting the NetWare file system directory object attribute values, which include Directory Space Information.
- com.novell.service.file.nw.DirectorySpaceInformation class provides support for NetWare file system directory attribute values and operations.
- com.novell.service.file.nw.NetwareVolume interface is used for getting the NetWare file system volume object attribute values, which include Volume Information, Volume Restriction, Volume Utilization, and Trustee Path Enumeration.
- com.novell.service.file.nw.VolumeInformation class provides variables, constructors and methods for accessing volume information attribute values.
- com.novell.service.file.nw.VolumeRestriction class provides variables, constructors and methods for accessing volume restriction attribute values associated with a given volume, which can have multiple restrictions.
- com.novell.service.file.nw.VolumeRestrictionEnumerator interface provides for obtaining an enumeration of volume restriction attributes of a volume, which can have multiple restrictions.
- com.novell.service.file.nw.VolumeUtilization class provides variables, constructors and methods for accessing the volume utilization attribute value. This attribute value is unique in that it requires the objectName to be set by the user before it can obtain the values. Because of this the attribute value cannot be setup for searching; only the default constructor is available.
- com.novell.java.io.DataAccessable interface enables you to read and write streams with JNDI provider contexts by identifying an object that may support input/output streams and random access to data. A typical usage of an object of this type is to pass it to the various constructors of the NInputStream, NOutputStream and RandomAccess classes (or provider specific extensions of these classes). These constructors all take a DataAccessable object as a parameter and then implement themselves in terms of this input parameter.
- com.novell.service.file.nw.DataAccessableParameters interface provides the file systems implementation of the custom data parameter passed as the custom parameter to the various NInputStream, NOutputStream and RandomAccess constructors. This class defines constants that can be used for the various constructors in these classes, or this object can be instantiated and passed into the custom parameter constructors. The custom parameters associated with file streams are: openFlags and dataSelector.
- com.novell.java.io.NInputStream class provides input stream functionality to some data device object, which implements the DataAccessable interface. The various constructors of this class open an input stream on (or with) the DataAccessable object passed into the constructors.
- com.novell.service.file.nw.NFileInputStream class opens an input stream on a NetWare file or Extended Attribute. It extends the NInputStream class by adding convenience constructors for the various custom parameters. The DataAccessableParameters class can also be used by the user application layer to obtain constant flags for the various constructors or it can instantiate a DataAccessableParameters object, which it passes into the NInputStream constructor.
- com.novell.java.io.NOutputStream class provides output stream functionality to some data device object, which implements the DataAccessable interface. The various constructors of this class open an output stream on (or with) the DataAccessable object passed into the constructors.
- com.novell.service.file.nw.NFileOutputStream class opens an output stream on a NetWare file or Extended Attribute. It extends the NOutputStream class by adding convenience constructors for the various custom parameters. The DataAccessableParameters class can also be used by the user application layer to obtain constant flags for the various constructors or it can instantiate a DataAccessableParameters object, which it passes into the NOutputStream constructor.
- com.novell.java.io.RandomAccess class provides random access functionality to some data devices, which implement the DataAccessable interface. The various constructors of this class open access on (or with) the DataAccessable object passed into the constructors.
- com.novell.service.file.nw.NRandomAccessFile class opens a random access on a NetWare file. It extends the RandomAccess class by adding convenience constructors for the various custom parameters. The DataAccessableParameters class can also be used by the user application layer to obtain constant flags for the various constructors or it can instantiate a DataAccessableParameters object, which it passes into the RandomAccess constructor.
2.6.3 File System Initial Context Implementations
In order to access the File System interfaces and classes, you must specify an initial context factory to use. Following is an example of how the File System initial context factory implementation might be done.
Hashtable properties = new Hashtable();
property.put(Context.INITIAL_CONTEXT_FACTORY,
"com.novell.service.file.nw.FileSystemInitialContextFactory");
property.put(Context.PROVIDER_URL, <server name>);
DirContext initCtx = new InitialDirContext(properties);
To access the Server through federation you might do the following:
serverDirContext = lookup(<server name>+"/");
After the initial context has been implemented, you can then get the session environment object using code similar to the following:
InitialContext initCtx = new InitialContext (hash);
hash = initCtx.getEnvironment ();
Session sess = (Session) hash.get (Environment.SESSION.OBJECT);
For a detailed discussion of initial context implementation see Initial Context Implementations in the Novell Services Introduction.
2.6.4 Important File System Provider Methods
Listed below are some of the most important File System Provider methods available. All methods are accessible by going to each of the file system components.
File System Methods (com.novell.service.file.nw Package)
- NameSpace.getPlatformDefaultNameSpace - Returns the default NetWare name space depending on the OS under which the current JVM is running.
- NetwareFile.getDirectoryEntryInformation - Returns a DirectoryEntryInformation object associated with this directory entry (file or directory).
- NetwareFile.setDirectoryEntryInformation - Modifies the back end DirectoryEntryInformation object associated with this directory entry (file or directory).
- NetwareFile.getEAEnumerator - Returns the EAEnumerator object associated with this directory entry (file or directory).
- NetwareFile.getEffectiveRights - Returns the EffectiveRights object associated with this directory entry (file or directory).
- NetwareFile.setExtendedAttribute - Modifies the back end ExtendedAttribute object associated with this directory entry (file or directory).
- NetwareFile.getTrusteeEnumerator - Returns the TrusteeEnumerator object associated with this directory entry (file or directory).
- NetwareFile.setTrustee - Modifies the back end Trustee attribute object associated with this directory entry (file or directory).
- NetwareDirectory.getDirectorySpaceInformation - Returns the DirectorySpaceInformation object associated with this directory entry (file or directory).
- NetwareDirectory.setDirectorySpaceInformation - Modifies the back end DirectorySpaceInformation object associated with this directory entry (file or directory).
- NetwareVolume.getVolumeInformation - Returns the VolumeInformation object associated with this volume.
- NetwareVolume.getVolumeUtilization - Returns the VolumeUtilization object associated with this volume.
- NetwareVolume.getVolumeRestrictionEnumerator - Returns the VolumeRestrictionEnumerator object associated with this volume.
- NetwareVolume.getTrusteePathEnumerator - Returns the TrusteePathEnumerator object associated with this volume.
- NetwareVolume.setVolumeRestriction - Modifies the back end VolumeRestriction object associated with this volume.
File Stream Accessor Methods (com.novell.java.io Package)
- DataAccessable.supportsInputStream - Reports if this accessor supports input stream.
- DataAccessable.supportsOutputStream - Reports if this accessor supports output stream.
- DataAccessable.supportsRandomAccess - Reports if this accessor supports random access.
- DataAccessable.supportsSubordinateInputStream - Reports if this accessor supports subordinate input streams.
- DataAccessable.supportsSubordinateOutputStream - Reports if this accessor supports subordinate input streams.
- DataAccessable.supportsSubordinateRandomAccess - Reports if this accessor supports subordinate random access.
2.6.5 Relationship of File System Interfaces and Classes
Because the com.novell.service.file.nw package components are extended from the com.novell.java.io streams components to provide NetWare specific extensions of the various streams interfaces, the relationships between the NetWare File System components is illustrated in two diagrams:
NetWare File System Components
The relationship between the NetWare File System interfaces and classes is illustrated in the diagram below, followed by a brief description of the relationship each interface and class has with other interfaces and classes.
Figure 2-9 NetWare File System Components
In this diagram of interfaces and classes a solid red line ending with a solid arrow represents an extension of a class. The dotted black lines ending with a small solid arrow imply some relationships between the different interfaces and classes. Links are provided to the Reference Guide documentation for each of these important file system interfaces and classes.
- com.novell.service.file.nw.NameSpace class has no direct relationship with other interfaces and classes of the NetWare file system. Its main purpose is to get the default name space for the platform on which the JVM is executing.
- com.novell.java.io.NFile interface is extended by the NetwareFile interface in the com.novell.service.file.nw package.
- com.novell.service.file.nw.NetwareFile interface extends the com.novell.java.io.NFile interface. NetwareFile interface methods are available for obtaining and setting Directory Entry Information, Effective Rights, Extended Attributes, and Trustee attribute values associated with a file object.
- com.novell.service.file.nw.DirectoryEntryInformation class provides the NetWareFile interface with 26 attribute values of Directory Entry Information associated with a directory entry, which can be a file or a directory.
- com.novell.service.file.nw.EffectiveRights class provides the NetWareFile interface with the effective rights for a file or a directory.
- com.novell.service.file.nw.ExtendedAttribute class provides the NetWareFile interface with extended attribute information associated with a given file, which can have multiple extended attributes that are enumerated using the EAEnumerator interface.
- com.novell.service.file.nw.EAEnumerator interface enumerates the extended attributes of a given file, which can have multiple extended attributes.
- com.novell.service.file.nw.Trustee class provides the NetWareFile interface with information identifying a trustee, the rights associated with the named trustee, and a compare string for a given directory entry (file or directory), which can have multiple trustees that are enumerated using the TrusteeEnumerator interface.
- com.novell.service.file.nw.TrusteeEnumerator interface enumerates the trustees of a given directory entry (file or directory), which can have multiple trustees.
- com.novell.service.file.nw.TrusteePathEnumerator interface provides information on all paths of a volume to which a user is assigned as a trustee.
- com.novell.service.file.nw.NetwareDirectory interface extends the NetwareFile interface and provides methods for obtaining and setting directory object attribute values, which include directory space information.
- com.novell.service.file.nw.DirectorySpaceInformation class provides the NetwareDirectory interface with directory object attribute values.
- com.novell.service.file.nw.NetwareVolume interface extends the NetwareDirectory interface. Methods are provided for getting the NetWare file system volume object attribute values, which include volume information, volume restriction information, volume utilization information, and trustee path enumeration information.
- com.novell.service.file.nw.VolumeInformation class provides the NetwareVolume interface with volume information attribute values associated with a given volume.
- com.novell.service.file.nw.VolumeRestriction class provides the NetwareVolume interface with volume restriction attribute values associated with a given volume, which can have multiple restrictions.
- com.novell.service.file.nw.VolumeRestrictionEnumerator interface enumerates volume restriction attributes of a volume, which can have multiple restrictions.
- com.novell.service.file.nw.VolumeUtilization class provides the NetwareVolume interface with volume utilization attribute values.
NetWare Stream Accessor Components
The relationship between the NetWare stream accessor interfaces and classes is illustrated in the diagram below, followed by a brief description of the relationship each interface and class has with other interfaces and classes.
Figure 2-10 NetWare Stream Accessor Components
In this diagram of interfaces and classes a solid red line ending with a solid arrow represents an extension of a class. The dotted black lines ending with a small solid arrow imply some relationships between the different interfaces and classes. Links are provided to the Reference Guide documentation for each of these important file stream interfaces and classes.
- com.novell.java.io.spi.DataAccessor interface provides an interface that allows read and/or write access to a given resource. DataAccessor is not used by the user application layer, but is used by Stream service provider implementors.
- com.novell.java.io.DataAccessable interface provides a DataAccessable object to the various constructors of the NInputStream, NOutputStream and RandomAccess classes (or provider specific extensions of these classes). These constructors all take a DataAccessable object as a parameter and then implement themselves in terms of this input parameter.
- com.novell.service.file.nw.DataAccessableParameters interface passes the custom data parameter through DataAccessable objects to the various NInputStream, NOutputStream and RandomAccess constructors. The custom parameters associated with file streams are: openFlags and dataSelector.
- com.novell.java.io.NInputStream class is extended by the com.novell.service.file.nw.NFileInputStream class. The various constructors of the NInputStream class open an input stream on (or with) the DataAccessable object passed into the constructors.
- com.novell.service.file.nw.NFileInputStream class extends the com.novell.java.io.NInputStream class by adding convenience constructors for the various custom parameters.
- com.novell.java.io.NOutputStream class is extended by the com.novell.service.file.nw.NFileOutputStream class. The various constructors of the NOutputStream class open an output stream on (or with) the DataAccessable object passed into the constructors.
- com.novell.service.file.nw.NFileOutputStream class extends the com.novell.java.io.NOutputStream class by adding convenience constructors for the various custom parameters.
- com.novell.java.io.RandomAccess class is extended by the com.novell.service.file.nw.NRandomAccessFile class. The various constructors of the RandomAccess class open a random access file on (or with) the DataAccessable object passed into the constructors.
- com.novell.service.file.nw.NRandomAccessFile class extends the com.novell.java.io.RandomAccess class by adding convenience constructors for the various custom parameters.