public abstract class Configuration extends Object
 A login configuration contains the following information.
 Note that this example only represents the default syntax for the
 Configuration.  Subclass implementations of this class
 may implement alternative syntaxes and may retrieve the
 Configuration from any source such as files, databases,
 or servers.
 
      Name {
            ModuleClass  Flag    ModuleOptions;
            ModuleClass  Flag    ModuleOptions;
            ModuleClass  Flag    ModuleOptions;
      };
      Name {
            ModuleClass  Flag    ModuleOptions;
            ModuleClass  Flag    ModuleOptions;
      };
      other {
            ModuleClass  Flag    ModuleOptions;
            ModuleClass  Flag    ModuleOptions;
      };
 
  Each entry in the Configuration is indexed via an
 application name, Name, and contains a list of
 LoginModules configured for that application.  Each LoginModule
 is specified via its fully qualified class name.
 Authentication proceeds down the module list in the exact order specified.
 If an application does not have specific entry,
 it defaults to the specific entry for "other".
 
The Flag value controls the overall behavior as authentication proceeds down the stack. The following represents a description of the valid values for Flag and their respective semantics:
      1) Required     - The LoginModule is required to succeed.
                      If it succeeds or fails, authentication still continues
                      to proceed down the LoginModule list.
      2) Requisite    - The LoginModule is required to succeed.
                      If it succeeds, authentication continues down the
                      LoginModule list.  If it fails,
                      control immediately returns to the application
                      (authentication does not proceed down the
                      LoginModule list).
      3) Sufficient   - The LoginModule is not required to
                      succeed.  If it does succeed, control immediately
                      returns to the application (authentication does not
                      proceed down the LoginModule list).
                      If it fails, authentication continues down the
                      LoginModule list.
      4) Optional     - The LoginModule is not required to
                      succeed.  If it succeeds or fails,
                      authentication still continues to proceed down the
                      LoginModule list.
 
  The overall authentication succeeds only if all Required and
 Requisite LoginModules succeed.  If a Sufficient
 LoginModule is configured and succeeds,
 then only the Required and Requisite LoginModules prior to
 that Sufficient LoginModule need to have succeeded for
 the overall authentication to succeed. If no Required or
 Requisite LoginModules are configured for an application,
 then at least one Sufficient or Optional
 LoginModule must succeed.
 
 ModuleOptions is a space separated list of
 LoginModule-specific values which are passed directly to
 the underlying LoginModules.  Options are defined by the
 LoginModule itself, and control the behavior within it.
 For example, a LoginModule may define options to support
 debugging/testing capabilities.  The correct way to specify options in the
 Configuration is by using the following key-value pairing:
 debug="true".  The key and value should be separated by an
 'equals' symbol, and the value should be surrounded by double quotes.
 If a String in the form, ${system.property}, occurs in the value,
 it will be expanded to the value of the system property.
 Note that there is no limit to the number of
 options a LoginModule may define.
 
 The following represents an example Configuration entry
 based on the syntax above:
 
 Login {
   com.sun.security.auth.module.UnixLoginModule required;
   com.sun.security.auth.module.Krb5LoginModule optional
                   useTicketCache="true"
                   ticketCache="${user.home}${/}tickets";
 };
 
  This Configuration specifies that an application named,
 "Login", requires users to first authenticate to the
 com.sun.security.auth.module.UnixLoginModule, which is
 required to succeed.  Even if the UnixLoginModule
 authentication fails, the
 com.sun.security.auth.module.Krb5LoginModule
 still gets invoked.  This helps hide the source of failure.
 Since the Krb5LoginModule is Optional, the overall
 authentication succeeds only if the UnixLoginModule
 (Required) succeeds.
 
Also note that the LoginModule-specific options, useTicketCache="true" and ticketCache=${user.home}${/}tickets", are passed to the Krb5LoginModule. These options instruct the Krb5LoginModule to use the ticket cache at the specified location. The system properties, user.home and / (file.separator), are expanded to their respective values.
 There is only one Configuration object installed in the runtime at any
 given time.  A Configuration object can be installed by calling the
 setConfiguration method.  The installed Configuration object
 can be obtained by calling the getConfiguration method.
 
 If no Configuration object has been installed in the runtime, a call to
 getConfiguration installs an instance of the default
 Configuration implementation (a default subclass implementation of this
 abstract class).
 The default Configuration implementation can be changed by setting the value
 of the "login.configuration.provider" security property (in the Java
 security properties file) to the fully qualified name of the desired
 Configuration subclass implementation.  The Java security properties file
 is located in the file named <JAVA_HOME>/lib/security/java.security.
 <JAVA_HOME> refers to the value of the java.home system property,
 and specifies the directory where the JRE is installed.
 
 Application code can directly subclass Configuration to provide a custom
 implementation.  In addition, an instance of a Configuration object can be
 constructed by invoking one of the getInstance factory methods
 with a standard type.  The default policy type is "JavaLoginConfig".
 See the Configuration section in the 
 Java Cryptography Architecture Standard Algorithm Name Documentation
 for a list of standard Configuration types.
LoginContext| Modifier and Type | Class and Description | 
|---|---|
| static interface  | Configuration.ParametersThis represents a marker interface for Configuration parameters. | 
| Modifier | Constructor and Description | 
|---|---|
| protected  | Configuration()Sole constructor. | 
| Modifier and Type | Method and Description | 
|---|---|
| abstract AppConfigurationEntry[] | getAppConfigurationEntry(String name)Retrieve the AppConfigurationEntries for the specified name
 from this Configuration. | 
| static Configuration | getConfiguration()Get the installed login Configuration. | 
| static Configuration | getInstance(String type,
           Configuration.Parameters params)Returns a Configuration object of the specified type. | 
| static Configuration | getInstance(String type,
           Configuration.Parameters params,
           Provider provider)Returns a Configuration object of the specified type. | 
| static Configuration | getInstance(String type,
           Configuration.Parameters params,
           String provider)Returns a Configuration object of the specified type. | 
| Configuration.Parameters | getParameters()Return Configuration parameters. | 
| Provider | getProvider()Return the Provider of this Configuration. | 
| String | getType()Return the type of this Configuration. | 
| void | refresh()Refresh and reload the Configuration. | 
| static void | setConfiguration(Configuration configuration)Set the login  Configuration. | 
protected Configuration()
public static Configuration getConfiguration()
Configuration.setConfiguration method,
          then that object is returned.  Otherwise, a default
          Configuration object is returned.SecurityException - if the caller does not have permission
                          to retrieve the Configuration.setConfiguration(javax.security.auth.login.Configuration)public static void setConfiguration(Configuration configuration)
Configuration.
 configuration - the new ConfigurationSecurityException - if the current thread does not have
                  Permission to set the Configuration.getConfiguration()public static Configuration getInstance(String type, Configuration.Parameters params) throws NoSuchAlgorithmException
This method traverses the list of registered security providers, starting with the most preferred Provider. A new Configuration object encapsulating the ConfigurationSpi implementation from the first Provider that supports the specified type is returned.
 Note that the list of registered providers may be retrieved via
 the Security.getProviders() method.
type - the specified Configuration type.  See the Configuration
    section in the 
    Java Cryptography Architecture Standard Algorithm Name
    Documentation for a list of standard Configuration types.params - parameters for the Configuration, which may be null.SecurityException - if the caller does not have permission
          to get a Configuration instance for the specified type.NullPointerException - if the specified type is null.IllegalArgumentException - if the specified parameters
          are not understood by the ConfigurationSpi implementation
          from the selected Provider.NoSuchAlgorithmException - if no Provider supports a
          ConfigurationSpi implementation for the specified type.Providerpublic static Configuration getInstance(String type, Configuration.Parameters params, String provider) throws NoSuchProviderException, NoSuchAlgorithmException
A new Configuration object encapsulating the ConfigurationSpi implementation from the specified provider is returned. The specified provider must be registered in the provider list.
 Note that the list of registered providers may be retrieved via
 the Security.getProviders() method.
type - the specified Configuration type.  See the Configuration
    section in the 
    Java Cryptography Architecture Standard Algorithm Name
    Documentation for a list of standard Configuration types.params - parameters for the Configuration, which may be null.provider - the provider.SecurityException - if the caller does not have permission
          to get a Configuration instance for the specified type.NullPointerException - if the specified type is null.IllegalArgumentException - if the specified provider
          is null or empty,
          or if the specified parameters are not understood by
          the ConfigurationSpi implementation from the specified provider.NoSuchProviderException - if the specified provider is not
          registered in the security provider list.NoSuchAlgorithmException - if the specified provider does not
          support a ConfigurationSpi implementation for the specified
          type.Providerpublic static Configuration getInstance(String type, Configuration.Parameters params, Provider provider) throws NoSuchAlgorithmException
A new Configuration object encapsulating the ConfigurationSpi implementation from the specified Provider object is returned. Note that the specified Provider object does not have to be registered in the provider list.
type - the specified Configuration type.  See the Configuration
    section in the 
    Java Cryptography Architecture Standard Algorithm Name
    Documentation for a list of standard Configuration types.params - parameters for the Configuration, which may be null.provider - the Provider.SecurityException - if the caller does not have permission
          to get a Configuration instance for the specified type.NullPointerException - if the specified type is null.IllegalArgumentException - if the specified Provider is null,
          or if the specified parameters are not understood by
          the ConfigurationSpi implementation from the specified Provider.NoSuchAlgorithmException - if the specified Provider does not
          support a ConfigurationSpi implementation for the specified
          type.Providerpublic Provider getProvider()
 This Configuration instance will only have a Provider if it
 was obtained via a call to Configuration.getInstance.
 Otherwise this method returns null.
public String getType()
 This Configuration instance will only have a type if it
 was obtained via a call to Configuration.getInstance.
 Otherwise this method returns null.
public Configuration.Parameters getParameters()
 This Configuration instance will only have parameters if it
 was obtained via a call to Configuration.getInstance.
 Otherwise this method returns null.
public abstract AppConfigurationEntry[] getAppConfigurationEntry(String name)
name - the name used to index the Configuration.public void refresh()
 This method causes this Configuration object to refresh/reload its
 contents in an implementation-dependent manner.
 For example, if this Configuration object stores its entries in a file,
 calling refresh may cause the file to be re-read.
 
The default implementation of this method does nothing. This method should be overridden if a refresh operation is supported by the implementation.
SecurityException - if the caller does not have permission
                          to refresh its Configuration. Submit a bug or feature 
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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