org.apache.hadoop.security
Class UnixUserGroupInformation

java.lang.Object
  org.apache.hadoop.security.UserGroupInformation
      org.apache.hadoop.security.UnixUserGroupInformation

All Implemented Interfaces:

Writable

public class UnixUserGroupInformation
extends UserGroupInformation

An implementation of UserGroupInformation in the Unix system

Field Summary

static String

UGI_PROPERTY_NAME

Fields inherited from class org.apache.hadoop.security.UserGroupInformation

LOG

Constructor Summary

UnixUserGroupInformation()
Default constructor

UnixUserGroupInformation(String[] ugi)
Constructor with parameter user/group names

UnixUserGroupInformation(String userName, String[] groupNames)
Constructor with parameters user name and its group names.

Method Summary

static UnixUserGroupInformation	createImmutable(String[] ugi) Create an immutable UnixUserGroupInformation object.
boolean	equals(Object other) Decide if two UGIs are the same
String[]	getGroupNames() Return an array of group names
String	getUserName() Return the user's name
int	hashCode() Returns a hash code for this UGI.
static UnixUserGroupInformation	login() Get current user's name and the names of all its groups from Unix.
static UnixUserGroupInformation	login(Configuration conf) Equivalent to login(conf, false).
static UnixUserGroupInformation	login(Configuration conf, boolean save) Get a user's name & its group names from the given configuration; If it is not defined in the configuration, get the current user's information from Unix.
void	readFields(DataInput in) Deserialize this object First check if this is a UGI in the string format.
static UnixUserGroupInformation	readFromConf(Configuration conf, String attr) Read a UGI from the given conf The object is expected to store with the property name attr as a comma separated string that starts with the user name followed by group names.
static void	saveToConf(Configuration conf, String attr, UnixUserGroupInformation ugi) Store the given ugi as a comma separated string in conf as a property attr The String starts with the user name followed by the default group names, and other group names.
String	toString() Convert this object to a string
void	write(DataOutput out) Serialize this object First write a string marking that this is a UGI in the string format, then write this object's serialized form to the given data output

Methods inherited from class org.apache.hadoop.security.UserGroupInformation

getCurrentUGI, readFrom, setCurrentUGI

Methods inherited from class java.lang.Object

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

Field Detail

UGI_PROPERTY_NAME

public static final String UGI_PROPERTY_NAME

See Also:

Constant Field Values

Constructor Detail

UnixUserGroupInformation

public UnixUserGroupInformation()

Default constructor

UnixUserGroupInformation

public UnixUserGroupInformation(String userName,
                                String[] groupNames)

Constructor with parameters user name and its group names. The first entry in the groups list is the default group.

Parameters:

userName - a user's name

groupNames - groups list, first of which is the default group

Throws:

IllegalArgumentException - if any argument is null

UnixUserGroupInformation

public UnixUserGroupInformation(String[] ugi)

Constructor with parameter user/group names

Parameters:

ugi - an array containing user/group names, the first element of which is the user name, the second of which is the default group name.

Throws:

IllegalArgumentException - if the array size is less than 2 or any element is null.

Method Detail

createImmutable

public static UnixUserGroupInformation createImmutable(String[] ugi)

Create an immutable UnixUserGroupInformation object.

getGroupNames

public String[] getGroupNames()

Return an array of group names

Specified by:

getGroupNames in class UserGroupInformation

Returns:

an array of group names

getUserName

public String getUserName()

Return the user's name

Specified by:

getUserName in class UserGroupInformation

Returns:

the user's name

readFields

public void readFields(DataInput in)
                throws IOException

Deserialize this object First check if this is a UGI in the string format. If no, throw an IOException; otherwise set this object's fields by reading them from the given data input

Parameters:

in - input stream

Throws:

IOException - is thrown if encounter any error when reading

write

public void write(DataOutput out)
           throws IOException

Serialize this object First write a string marking that this is a UGI in the string format, then write this object's serialized form to the given data output

Parameters:

out - output stream

Throws:

IOException - if encounter any error during writing

saveToConf

public static void saveToConf(Configuration conf,
                              String attr,
                              UnixUserGroupInformation ugi)

Store the given ugi as a comma separated string in conf as a property attr The String starts with the user name followed by the default group names, and other group names.

Parameters:

conf - configuration

attr - property name

ugi - a UnixUserGroupInformation

readFromConf

public static UnixUserGroupInformation readFromConf(Configuration conf,
                                                    String attr)
                                             throws LoginException

Read a UGI from the given conf The object is expected to store with the property name attr as a comma separated string that starts with the user name followed by group names. If the property name is not defined, return null. It's assumed that there is only one UGI per user. If this user already has a UGI in the ugi map, return the ugi in the map. Otherwise, construct a UGI from the configuration, store it in the ugi map and return it.

Parameters:

conf - configuration

attr - property name

Returns:

a UnixUGI

Throws:

LoginException - if the stored string is ill-formatted.

login

public static UnixUserGroupInformation login()
                                      throws LoginException

Get current user's name and the names of all its groups from Unix. It's assumed that there is only one UGI per user. If this user already has a UGI in the ugi map, return the ugi in the map. Otherwise get the current user's information from Unix, store it in the map, and return it.

Throws:

LoginException

login

public static UnixUserGroupInformation login(Configuration conf)
                                      throws LoginException

Equivalent to login(conf, false).

Throws:

LoginException

login

public static UnixUserGroupInformation login(Configuration conf,
                                             boolean save)
                                      throws LoginException

Get a user's name & its group names from the given configuration; If it is not defined in the configuration, get the current user's information from Unix. If the user has a UGI in the ugi map, return the one in the UGI map.

Parameters:

conf - either a job configuration or client's configuration

save - saving it to conf?

Returns:

UnixUserGroupInformation a user/group information

Throws:

LoginException - if not able to get the user/group information

equals

public boolean equals(Object other)

Decide if two UGIs are the same

Overrides:

equals in class Object

Parameters:

other - other object

Returns:

true if they are the same; false otherwise.

hashCode

public int hashCode()

Returns a hash code for this UGI. The hash code for a UGI is the hash code of its user name string.

Overrides:

hashCode in class Object

Returns:

a hash code value for this UGI.

toString

public String toString()

Convert this object to a string

Overrides:

toString in class Object

Returns:

a comma separated string containing the user name and group names