FsFederatingController (TrueZIP Kernel 7.4.1 API)

java.lang.Object
- de.schlichtherle.truezip.fs.FsController<M>
- - de.schlichtherle.truezip.fs.FsModelController<M>
  - - de.schlichtherle.truezip.fs.FsDecoratingController<FsModel,FsController<?>>
    - - de.schlichtherle.truezip.fs.FsFederatingController

```
@ThreadSafe
@DefaultAnnotation(value=edu.umd.cs.findbugs.annotations.NonNull.class)
public final class FsFederatingController
extends FsDecoratingController<FsModel,FsController<?>>
```
Implements a chain of responsibility in order to resolve FsFalsePositiveExceptions thrown by the prospective file system provided to its constructor.
Whenever the controller for the prospective file system throws a FsFalsePositiveException, the method call is delegated to the controller for its parent file system in order to resolve the requested operation. If this method call fails with another exception, then the IOException which is associated as the cause of the first exception gets rethrown unless the second exception is an FsException again. In this case the FsException gets rethrown as is in order to enable the caller to resolve it, which is typically - but not necessarily - the TrueZIP Kernel again.
This algorithm effectively achieves the following objectives:
1. False positive federated file systems (i.e. false positive archive files) get resolved correctly by accessing them as entities of the parent file system.
2. If the file system driver for the parent file system throws another exception, then it gets discarded and the exception initially thrown by the file system driver for the false positive archive file takes its place in order to provide the caller with a good indication of what went wrong in the first place.
3. Exceptions which are thrown by the TrueZIP Kernel itself identify themselves by the type FsException and are excempt from this masquerade in order to support resolving them by a more competent caller.
As an example consider the case of accessing a RAES encrypted ZIP file. When an archive file of this type gets mounted, the user is typically prompted for a password. If the user cancels the password prompting dialog, then an appropriate exception gets thrown. Some other class in the TrueZIP Kernel would then catch this exception and flag the archive file as a false positive by wrapping the exception in a FsFalsePositiveException. This class would then catch this false positive exception and try to resolve the issue by using the parent file system controller. Failing that, the initial exception would get rethrown in order to signal to the caller that the user had cancelled password prompting.
Author:

Christian Schlichtherle

See Also:
FsFalsePositiveException

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

private class FsFederatingController.Input

private class FsFederatingController.Output

Nested Classes
Modifier and Type	Class and Description
`private class`	`FsFederatingController.Input`
`private class`	`FsFederatingController.Output`

Field Summary

Fields
Modifier and Type Field and Description

private FsPath path
- Fields inherited from class de.schlichtherle.truezip.fs.FsDecoratingController
  delegate

Fields
Modifier and Type	Field and Description
`private FsPath`	`path`

Constructor Summary

Constructors
Constructor and Description

FsFederatingController(FsController<?> controller)
Constructs a new file system federating controller.

Constructors
Constructor and Description
`FsFederatingController(FsController<?> controller)` Constructs a new file system federating controller.

Method Summary

Methods
Modifier and Type	Method and Description
`Icon`	`getClosedIcon()`
`FsEntry`	`getEntry(FsEntryName name)` Returns a file system entry or `null` if no file system entry exists for the given name.
`InputSocket<?>`	`getInputSocket(FsEntryName name, BitField<FsInputOption> options)` Returns an input socket for reading the contents of the file system entry addressed by the given name from the file system.
`Icon`	`getOpenIcon()`
`OutputSocket<?>`	`getOutputSocket(FsEntryName name, BitField<FsOutputOption> options, Entry template)` Returns an output socket for writing the contents of the entry addressed by the given name to the file system.
`private FsPath`	`getPath()`
`boolean`	`isReadable(FsEntryName name)` Returns `false` if the named file system entry is not readable.
`boolean`	`isReadOnly()` Returns `true` if and only if the file system is read-only.
`boolean`	`isWritable(FsEntryName name)` Returns `false` if the named file system entry is not writable.
`void`	`mknod(FsEntryName name, Entry.Type type, BitField<FsOutputOption> options, Entry template)` Creates or replaces and finally links a chain of one or more entries for the given entry `name` into the file system.
`private FsEntryName`	`resolveParent(FsEntryName name)`
`void`	`setReadOnly(FsEntryName name)`
`boolean`	`setTime(FsEntryName name, BitField<Entry.Access> types, long value, BitField<FsOutputOption> options)` Makes an attempt to set the last access time of all types in the given bit field for the file system entry with the given name.
`boolean`	`setTime(FsEntryName name, Map<Entry.Access,Long> times, BitField<FsOutputOption> options)` Makes an attempt to set the last access time of all types in the given map for the file system entry with the given name.
`void`	`unlink(FsEntryName name, BitField<FsOutputOption> options)` Removes the named file system entry from the file system.

Methods inherited from class de.schlichtherle.truezip.fs.FsDecoratingController
getParent, isExecutable, sync, toString

Methods inherited from class de.schlichtherle.truezip.fs.FsModelController
getModel, getMountPoint, isTouched, setTouched

Methods inherited from class de.schlichtherle.truezip.fs.FsController
equals, hashCode, sync

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - path
```
@CheckForNull
private volatile FsPath path
```
- Constructor Detail
  - FsFederatingController
```
FsFederatingController(FsController<?> controller)
```
    Constructs a new file system federating controller.
    
    Parameters:
    controller - the decorated file system controller.
- Method Detail
  - getClosedIcon
```
public Icon getClosedIcon()
                   throws IOException
```
    Overrides:
    
    getClosedIcon in class FsDecoratingController<FsModel,FsController<?>>
    
    Throws:
    
    IOException
  - getEntry
```
public FsEntry getEntry(FsEntryName name)
                 throws IOException
```
    Description copied from class: FsController
    
    Returns a file system entry or null if no file system entry exists for the given name. Modifying the returned object is either not supported (i.e. throws an UnsupportedOperationException) or does not show any effect on the file system.
    
    Overrides:
    
    getEntry in class FsDecoratingController<FsModel,FsController<?>>
    
    Parameters:
    name - the name of the file system entry.
    
    Returns:
    A file system entry or null if no file system entry exists for the given name.
    
    Throws:
    
    IOException - on any I/O error.
  - getInputSocket
```
public InputSocket<?> getInputSocket(FsEntryName name,
                            BitField<FsInputOption> options)
```
    Description copied from class: FsController
    
    Returns an input socket for reading the contents of the file system entry addressed by the given name from the file system.
    
    Overrides:
    
    getInputSocket in class FsDecoratingController<FsModel,FsController<?>>
    
    Parameters:
    name - the file system entry name.
    options - the input options.
    
    Returns:
    An InputSocket.
  - getOpenIcon
```
public Icon getOpenIcon()
                 throws IOException
```
    Overrides:
    
    getOpenIcon in class FsDecoratingController<FsModel,FsController<?>>
    
    Throws:
    
    IOException
  - getOutputSocket
```
public OutputSocket<?> getOutputSocket(FsEntryName name,
                              BitField<FsOutputOption> options,
                              @CheckForNull
                              Entry template)
```
    Description copied from class: FsController
    
    Returns an output socket for writing the contents of the entry addressed by the given name to the file system. If template is not null, then the output entry shall have as many of its properties copied as reasonable, e.g. the last modification time.
    
    Overrides:
    
    getOutputSocket in class FsDecoratingController<FsModel,FsController<?>>
    
    Parameters:
    name - a file system entry name.
    options - a bit field of output options.
    template - a nullable template for the properties of the output entry.
    
    Returns:
    An OutputSocket.
  - getPath
```
private FsPath getPath()
```
  - isReadable
```
public boolean isReadable(FsEntryName name)
                   throws IOException
```
    Description copied from class: FsController
    
    Returns false if the named file system entry is not readable.
    
    Overrides:
    
    isReadable in class FsDecoratingController<FsModel,FsController<?>>
    
    Parameters:
    name - the name of the file system entry.
    
    Returns:
    false if the named file system entry is not readable.
    
    Throws:
    
    IOException - On any I/O error.
  - isReadOnly
```
public boolean isReadOnly()
                   throws IOException
```
    Description copied from class: FsController
    
    Returns true if and only if the file system is read-only.
    
    Overrides:
    
    isReadOnly in class FsDecoratingController<FsModel,FsController<?>>
    
    Returns:
    true if and only if the file system is read-only.
    
    Throws:
    
    IOException - on any I/O error.
  - isWritable
```
public boolean isWritable(FsEntryName name)
                   throws IOException
```
    Description copied from class: FsController
    
    Returns false if the named file system entry is not writable.
    
    Overrides:
    
    isWritable in class FsDecoratingController<FsModel,FsController<?>>
    
    Parameters:
    name - the name of the file system entry.
    
    Returns:
    false if the named file system entry is not writable.
    
    Throws:
    
    IOException - On any I/O error.
  - mknod
```
public void mknod(FsEntryName name,
         Entry.Type type,
         BitField<FsOutputOption> options,
         @CheckForNull
         Entry template)
           throws IOException
```
    Description copied from class: FsController
    
    Creates or replaces and finally links a chain of one or more entries for the given entry name into the file system.
    Overrides:
    
    mknod in class FsDecoratingController<FsModel,FsController<?>>
    
    Parameters:
    name - the file system entry name.
    type - the file system entry type.
    options - the file system output options. If FsOutputOption.CREATE_PARENTS is set, any missing parent directories will be created and linked into the file system with its last modification time set to the system's current time.
    template - if not null, then the file system entry at the end of the chain shall inherit as much properties from this entry as possible - with the exception of its name and type.
    
    Throws:
    IOException - on any I/O error, including but not limited to these reasons:
    
    The file system is read only.
    name contains characters which are not supported by the file system.
    The entry already exists and either the option FsOutputOption.EXCLUSIVE is set or the entry is a directory.
    The entry exists as a different type.
    A parent entry exists but is not a directory.
    A parent entry is missing and createParents is false.
  - resolveParent
```
private FsEntryName resolveParent(FsEntryName name)
```
  - setReadOnly
```
public void setReadOnly(FsEntryName name)
                 throws IOException
```
    Overrides:
    
    setReadOnly in class FsDecoratingController<FsModel,FsController<?>>
    
    Throws:
    
    IOException
  - setTime
```
public boolean setTime(FsEntryName name,
              BitField<Entry.Access> types,
              long value,
              BitField<FsOutputOption> options)
                throws IOException
```
    Description copied from class: FsController
    
    Makes an attempt to set the last access time of all types in the given bit field for the file system entry with the given name. If false is returned or an IOException is thrown, then still some of the last access times may have been set. Whether or not this is an atomic operation is specific to the implementation.
    
    Overrides:
    
    setTime in class FsDecoratingController<FsModel,FsController<?>>
    
    Parameters:
    name - the file system entry name.
    types - the access types.
    value - the last access time.
    
    Returns:
    true if and only if setting the access time for all types in types succeeded.
    
    Throws:
    
    IOException - on any I/O error.
  - setTime
```
public boolean setTime(FsEntryName name,
              Map<Entry.Access,Long> times,
              BitField<FsOutputOption> options)
                throws IOException
```
    Description copied from class: FsController
    
    Makes an attempt to set the last access time of all types in the given map for the file system entry with the given name. If false is returned or an IOException is thrown, then still some of the last access times may have been set. Whether or not this is an atomic operation is specific to the implementation.
    
    Overrides:
    
    setTime in class FsDecoratingController<FsModel,FsController<?>>
    
    Parameters:
    name - the file system entry name.
    times - the access times.
    
    Returns:
    true if and only if setting the access time for all types in times succeeded.
    
    Throws:
    
    IOException - on any I/O error.
  - unlink
```
public void unlink(FsEntryName name,
          BitField<FsOutputOption> options)
            throws IOException
```
    Description copied from class: FsController
    
    Removes the named file system entry from the file system. If the named file system entry is a directory, it must be empty.
    
    Overrides:
    
    unlink in class FsDecoratingController<FsModel,FsController<?>>
    
    Parameters:
    name - the file system entry name.
    options - output options for this operation.
    
    Throws:
    
    IOException - On any I/O error.

Class FsFederatingController

Nested Class Summary

Field Summary

Fields inherited from class de.schlichtherle.truezip.fs.FsDecoratingController

Constructor Summary

Method Summary

Methods inherited from class de.schlichtherle.truezip.fs.FsDecoratingController

Methods inherited from class de.schlichtherle.truezip.fs.FsModelController

Methods inherited from class de.schlichtherle.truezip.fs.FsController

Methods inherited from class java.lang.Object

Field Detail

path

Constructor Detail

FsFederatingController

Method Detail

getClosedIcon

getEntry

getInputSocket

getOpenIcon

getOutputSocket

getPath

isReadable

isReadOnly

isWritable

mknod

resolveParent

setReadOnly

setTime

setTime

unlink