Package org.apache.hadoop.fs

Class XAttr

java.lang.Object

org.apache.hadoop.fs.XAttr

@Private
public class XAttr
extends java.lang.Object

XAttr is the POSIX Extended Attribute model similar to that found in traditional Operating Systems. Extended Attributes consist of one or more name/value pairs associated with a file or directory. Five namespaces are defined: user, trusted, security, system and raw. 1) USER namespace attributes may be used by any user to store arbitrary information. Access permissions in this namespace are defined by a file directory's permission bits. For sticky directories, only the owner and privileged user can write attributes.
2) TRUSTED namespace attributes are only visible and accessible to privileged users. This namespace is available from both user space (filesystem API) and fs kernel.
3) SYSTEM namespace attributes are used by the fs kernel to store system objects. This namespace is only available in the fs kernel. It is not visible to users.
4) SECURITY namespace attributes are used by the fs kernel for security features. It is not visible to users.
5) RAW namespace attributes are used for internal system attributes that sometimes need to be exposed. Like SYSTEM namespace attributes they are not visible to the user except when getXAttr/getXAttrs is called on a file or directory in the /.reserved/raw HDFS directory hierarchy. These attributes can only be accessed by the superuser.

See Also:

http://en.wikipedia.org/wiki/Extended_file_attributes

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	XAttr.Builder
static class	XAttr.NameSpace

Method Summary

Modifier and Type	Method	Description
boolean	equals(java.lang.Object obj)
boolean	equalsIgnoreValue(java.lang.Object obj)	Similar to equals(Object), except ignores the XAttr value.
java.lang.String	getName()
XAttr.NameSpace	getNameSpace()
byte[]	getValue()
int	hashCode()
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

getNameSpace

public XAttr.NameSpace getNameSpace()

getName

public java.lang.String getName()

getValue

public byte[] getValue()

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

equalsIgnoreValue

public boolean equalsIgnoreValue(java.lang.Object obj)

Similar to equals(Object), except ignores the XAttr value.

Parameters:

obj - to compare equality

Returns:

if the XAttrs are equal, ignoring the XAttr value

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object