UserGroupInformation (Hadoop 1.2.2-SNAPSHOT API)

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

```
public class UserGroupInformation
extends Object
```
User and group information for Hadoop. This class wraps around a JAAS Subject and provides methods to determine the user's username and groups. It supports both the Windows, Unix and Kerberos login modules.

嵌套类概要

嵌套类
限定符和类型	类和说明
`static class`	`UserGroupInformation.AuthenticationMethod` existing types of authentications' methods
`static class`	`UserGroupInformation.HadoopLoginModule` A login module that looks at the Kerberos, Unix, or Windows principal and adds the corresponding UserName.

字段概要

字段
限定符和类型字段和说明

static String HADOOP_TOKEN_FILE_LOCATION
Environment variable pointing to the token cache file

字段
限定符和类型	字段和说明
`static String`	`HADOOP_TOKEN_FILE_LOCATION` Environment variable pointing to the token cache file

方法概要

方法
限定符和类型	方法和说明
`boolean`	`addToken(Token<? extends TokenIdentifier> token)` Add a token to this UGI
`boolean`	`addTokenIdentifier(TokenIdentifier tokenId)` Add a TokenIdentifier to this UGI.
`void`	`checkTGTAndReloginFromKeytab()` Re-login a user from keytab if TGT is expired or is close to expiry.
`static UserGroupInformation`	`createProxyUser(String user, UserGroupInformation realUser)` Create a proxy user using username of the effective user and the ugi of the real user.
`static UserGroupInformation`	`createProxyUserForTesting(String user, UserGroupInformation realUser, String[] userGroups)` Create a proxy user UGI for testing HDFS and MapReduce
`static UserGroupInformation`	`createRemoteUser(String user)` Create a user from a login name.
`static UserGroupInformation`	`createUserForTesting(String user, String[] userGroups)` Create a UGI for testing HDFS and MapReduce
`<T> T`	`doAs(PrivilegedAction<T> action)` Run the given action as the user.
`<T> T`	`doAs(PrivilegedExceptionAction<T> action)` Run the given action as the user, potentially throwing an exception.
`boolean`	`equals(Object o)` Compare the subjects to see if they are equal to each other.
`UserGroupInformation.AuthenticationMethod`	`getAuthenticationMethod()` Get the authentication method from the subject
`static UserGroupInformation`	`getCurrentUser()` Return the current user, including any doAs in the current stack.
`String[]`	`getGroupNames()` Get the group names for this user.
`static UserGroupInformation`	`getLoginUser()` Get the currently logged in user.
`UserGroupInformation`	`getRealUser()` get RealUser (vs.
`String`	`getShortUserName()` Get the user's login name.
`protected Subject`	`getSubject()` Get the underlying subject from this ugi.
`Set<TokenIdentifier>`	`getTokenIdentifiers()` Get the set of TokenIdentifiers belonging to this UGI
`Collection<Token<? extends TokenIdentifier>>`	`getTokens()` Obtain the collection of tokens associated with this user.
`String`	`getUserName()` Get the user's full principal name.
`int`	`hashCode()` Return the hash of the subject.
`boolean`	`hasKerberosCredentials()` checks if logged in using kerberos
`boolean`	`isFromKeytab()` Is this user logged in from a keytab file?
`static boolean`	`isLoginKeytabBased()` Did the login happen via keytab
`static boolean`	`isSecurityEnabled()` Determine if UserGroupInformation is using Kerberos to determine user identities or is relying on simple authentication
`static void`	`loginUserFromKeytab(String user, String path)` Log a user in from a keytab file.
`static UserGroupInformation`	`loginUserFromKeytabAndReturnUGI(String user, String path)` Log a user in from a keytab file.
`static void`	`main(String[] args)` A test method to print out the current user's UGI.
`void`	`reloginFromKeytab()` Re-Login a user in from a keytab file.
`void`	`reloginFromTicketCache()` Re-Login a user in from the ticket cache.
`void`	`setAuthenticationMethod(UserGroupInformation.AuthenticationMethod authMethod)` Sets the authentication method in the subject
`static void`	`setConfiguration(Configuration conf)` Set the static configuration for UGI.
`String`	`toString()` Return the username.

从类继承的方法 java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- 字段详细资料
  - HADOOP_TOKEN_FILE_LOCATION
```
public static final String HADOOP_TOKEN_FILE_LOCATION
```
    Environment variable pointing to the token cache file
    
    另请参阅:
    常量字段值
- 方法详细资料
  - setConfiguration
```
public static void setConfiguration(Configuration conf)
```
    Set the static configuration for UGI. In particular, set the security authentication mechanism and the group look up service.
    
    参数:
    conf - the configuration to use
  - isSecurityEnabled
```
public static boolean isSecurityEnabled()
```
    Determine if UserGroupInformation is using Kerberos to determine user identities or is relying on simple authentication
    
    返回:
    true if UGI is working in a secure environment
  - hasKerberosCredentials
```
public boolean hasKerberosCredentials()
```
    checks if logged in using kerberos
    
    返回:
    true if the subject logged via keytab or has a Kerberos TGT
  - getCurrentUser
```
public static UserGroupInformation getCurrentUser()
                                           throws IOException
```
    Return the current user, including any doAs in the current stack.
    
    返回:
    the current user
    
    抛出:
    
    IOException - if login fails
  - getLoginUser
```
public static UserGroupInformation getLoginUser()
                                         throws IOException
```
    Get the currently logged in user.
    
    返回:
    the logged in user
    
    抛出:
    
    IOException - if login fails
  - isFromKeytab
```
public boolean isFromKeytab()
```
    Is this user logged in from a keytab file?
    
    返回:
    true if the credentials are from a keytab file.
  - loginUserFromKeytab
```
public static void loginUserFromKeytab(String user,
                       String path)
                                throws IOException
```
    Log a user in from a keytab file. Loads a user identity from a keytab file and logs them in. They become the currently logged-in user.
    
    参数:
    user - the principal name to load from the keytab
    path - the path to the keytab file
    
    抛出:
    
    IOException - if the keytab file can't be read
  - reloginFromTicketCache
```
public void reloginFromTicketCache()
                            throws IOException
```
    Re-Login a user in from the ticket cache. This method assumes that login had happened already. The Subject field of this UserGroupInformation object is updated to have the new credentials.
    
    抛出:
    
    IOException - on a failure
  - loginUserFromKeytabAndReturnUGI
```
public static UserGroupInformation loginUserFromKeytabAndReturnUGI(String user,
                                                   String path)
                                                            throws IOException
```
    Log a user in from a keytab file. Loads a user identity from a keytab file and login them in. This new user does not affect the currently logged-in user.
    
    参数:
    user - the principal name to load from the keytab
    path - the path to the keytab file
    
    抛出:
    
    IOException - if the keytab file can't be read
  - checkTGTAndReloginFromKeytab
```
public void checkTGTAndReloginFromKeytab()
                                  throws IOException
```
    Re-login a user from keytab if TGT is expired or is close to expiry.
    
    抛出:
    
    IOException
  - reloginFromKeytab
```
public void reloginFromKeytab()
                       throws IOException
```
    Re-Login a user in from a keytab file. Loads a user identity from a keytab file and logs them in. They become the currently logged-in user. This method assumes that loginUserFromKeytab(String, String) had happened already. The Subject field of this UserGroupInformation object is updated to have the new credentials.
    
    抛出:
    
    IOException - on a failure
  - isLoginKeytabBased
```
public static boolean isLoginKeytabBased()
                                  throws IOException
```
    Did the login happen via keytab
    
    返回:
    true or false
    
    抛出:
    
    IOException
  - createRemoteUser
```
public static UserGroupInformation createRemoteUser(String user)
```
    Create a user from a login name. It is intended to be used for remote users in RPC, since it won't have any credentials.
    
    参数:
    user - the full user principal name, must not be empty or null
    
    返回:
    the UserGroupInformation for the remote user.
  - createProxyUser
```
public static UserGroupInformation createProxyUser(String user,
                                   UserGroupInformation realUser)
```
    Create a proxy user using username of the effective user and the ugi of the real user.
    
    参数:
    user -
    realUser -
    
    返回:
    proxyUser ugi
  - getRealUser
```
public UserGroupInformation getRealUser()
```
    get RealUser (vs. EffectiveUser)
    
    返回:
    realUser running over proxy user
  - createUserForTesting
```
public static UserGroupInformation createUserForTesting(String user,
                                        String[] userGroups)
```
    Create a UGI for testing HDFS and MapReduce
    
    参数:
    user - the full user principal name
    userGroups - the names of the groups that the user belongs to
    
    返回:
    a fake user for running unit tests
  - createProxyUserForTesting
```
public static UserGroupInformation createProxyUserForTesting(String user,
                                             UserGroupInformation realUser,
                                             String[] userGroups)
```
    Create a proxy user UGI for testing HDFS and MapReduce
    
    参数:
    user - the full user principal name for effective user
    realUser - UGI of the real user
    userGroups - the names of the groups that the user belongs to
    
    返回:
    a fake user for running unit tests
  - getShortUserName
```
public String getShortUserName()
```
    Get the user's login name.
    
    返回:
    the user's name up to the first '/' or '@'.
  - getUserName
```
public String getUserName()
```
    Get the user's full principal name.
    
    返回:
    the user's full principal name.
  - addTokenIdentifier
```
public boolean addTokenIdentifier(TokenIdentifier tokenId)
```
    Add a TokenIdentifier to this UGI. The TokenIdentifier has typically been authenticated by the RPC layer as belonging to the user represented by this UGI.
    
    参数:
    tokenId - tokenIdentifier to be added
    
    返回:
    true on successful add of new tokenIdentifier
  - getTokenIdentifiers
```
public Set<TokenIdentifier> getTokenIdentifiers()
```
    Get the set of TokenIdentifiers belonging to this UGI
    
    返回:
    the set of TokenIdentifiers belonging to this UGI
  - addToken
```
public boolean addToken(Token<? extends TokenIdentifier> token)
```
    Add a token to this UGI
    
    参数:
    token - Token to be added
    
    返回:
    true on successful add of new token
  - getTokens
```
public Collection<Token<? extends TokenIdentifier>> getTokens()
```
    Obtain the collection of tokens associated with this user.
    
    返回:
    an unmodifiable collection of tokens associated with user
  - getGroupNames
```
public String[] getGroupNames()
```
    Get the group names for this user.
    
    返回:
    the list of users with the primary group first. If the command fails, it returns an empty list.
  - toString
```
public String toString()
```
    Return the username.
    
    覆盖:
    
    toString 在类中 Object
  - setAuthenticationMethod
```
public void setAuthenticationMethod(UserGroupInformation.AuthenticationMethod authMethod)
```
    Sets the authentication method in the subject
    
    参数:
    authMethod -
  - getAuthenticationMethod
```
public UserGroupInformation.AuthenticationMethod getAuthenticationMethod()
```
    Get the authentication method from the subject
    
    返回:
    AuthenticationMethod in the subject, null if not present.
  - equals
```
public boolean equals(Object o)
```
    Compare the subjects to see if they are equal to each other.
    
    覆盖:
    
    equals 在类中 Object
  - hashCode
```
public int hashCode()
```
    Return the hash of the subject.
    
    覆盖:
    
    hashCode 在类中 Object
  - getSubject
```
protected Subject getSubject()
```
    Get the underlying subject from this ugi.
    
    返回:
    the subject that represents this user.
  - doAs
```
public <T> T doAs(PrivilegedAction<T> action)
```
    Run the given action as the user.
    
    类型参数:
    T - the return type of the run method
    参数:
    action - the method to execute
    
    返回:
    the value from the run method
  - doAs
```
public <T> T doAs(PrivilegedExceptionAction<T> action)
       throws IOException,
              InterruptedException
```
    Run the given action as the user, potentially throwing an exception.
    
    类型参数:
    T - the return type of the run method
    参数:
    action - the method to execute
    
    返回:
    the value from the run method
    
    抛出:
    
    IOException - if the action throws an IOException
    
    Error - if the action throws an Error
    
    RuntimeException - if the action throws a RuntimeException
    
    InterruptedException - if the action throws an InterruptedException
    
    UndeclaredThrowableException - if the action throws something else
  - main
```
public static void main(String[] args)
                 throws Exception
```
    A test method to print out the current user's UGI.
    
    参数:
    args - if there are two arguments, read the user from the keytab and print it out.
    
    抛出:
    
    Exception

类 UserGroupInformation

嵌套类概要

字段概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

HADOOP_TOKEN_FILE_LOCATION

方法详细资料

setConfiguration

isSecurityEnabled

hasKerberosCredentials

getCurrentUser

getLoginUser

isFromKeytab

loginUserFromKeytab

reloginFromTicketCache

loginUserFromKeytabAndReturnUGI

checkTGTAndReloginFromKeytab

reloginFromKeytab

isLoginKeytabBased

createRemoteUser

createProxyUser

getRealUser

createUserForTesting

createProxyUserForTesting

getShortUserName

getUserName

addTokenIdentifier

getTokenIdentifiers

addToken

getTokens

getGroupNames

toString

setAuthenticationMethod

getAuthenticationMethod

equals

hashCode

getSubject

doAs

doAs

main