Package net.jini.config

Interface Configuration

All Known Implementing Classes:
AbstractConfiguration, AggregateConfig, ConfigurationFile, EmptyConfiguration, PlainConfiguration
public interface Configuration
Defines an interface for obtaining objects needed to configure applications, such as Exporter or ProxyPreparer instances, or other application-specific objects, from configuration files, databases, or other sources. Configuration entries are identified by a component and a name. Methods that retrieve entries can specify a default value to return in case the entry is not found, and supply data to use when computing the value of the entry.

Application developers are encouraged to use this interface, rather than explicitly constructing instances of exporters and proxy preparers, so that applications can be customized without requiring code modifications. Applications should normally use ConfigurationProvider to obtain Configuration instances, rather than referencing implementation classes directly, so that the interpretation of configuration options can be customized without requiring code modifications.

Since:
2.0
Author:
Sun Microsystems, Inc.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final Object
    NO_DATA
    An object to pass for data in calls to getEntry to specify no data.
    static final Object
    NO_DEFAULT
    An object to pass for defaultValue in calls to getEntry to specify no default value.

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    getEntry(String component, String name, Class type)
    Returns an object of the specified type created using the information in the entry matching the specified component and name, which must be found, and supplying no data.
    Object
    getEntry(String component, String name, Class type, Object defaultValue)
    Returns an object of the specified type created using the information in the entry matching the specified component and name, and supplying no data, returning the default value if no matching entry is found and the default value is not NO_DEFAULT.
    Object
    getEntry(String component, String name, Class type, Object defaultValue, Object data)
    Returns an object of the specified type created using the information in the entry matching the specified component and name, and using the specified data (unless it is NO_DATA), returning the default value if no matching entry is found and the default value is not NO_DEFAULT.

  • Field Details

  • Method Details

    • getEntry

      Object getEntry(String component, String name, Class type) throws ConfigurationException
      Returns an object of the specified type created using the information in the entry matching the specified component and name, which must be found, and supplying no data. If type is a primitive type, then the result is returned as an instance of the associated wrapper class. Repeated calls with the same arguments may or may not return the identical object.

      The component identifies the object whose behavior will be configured using the object returned. The value of component must be a QualifiedIdentifier, as defined in the Java(TM) Language Specification (JLS), and is typically the class or package name of the object being configured. The name identifies which of possibly several entries are available for the given component. The value of name must be an Identifier, as defined in the JLS.

      Calling this method is equivalent to calling getEntry(component, name, type, NO_DEFAULT, NO_DATA).

      Parameters:
      component - the component being configured
      name - the name of the entry for the component
      type - the type of the object to be returned
      Returns:
      an object created using the information in the entry matching component and name
      Throws:
      NoSuchEntryException - if no matching entry is found
      ConfigurationException - if a matching entry is found but a problem occurs creating the object for the entry, or if type is a reference type and the result for the matching entry is not either null or an instance of type, or if type is a primitive type and the result is not an instance of the associated wrapper class. Any Error thrown while creating the object is propagated to the caller; it is not wrapped in a ConfigurationException.
      IllegalArgumentException - if component is not null and is not a valid QualifiedIdentifier, or if name is not null and is not a valid Identifier
      NullPointerException - if any argument is null
      See Also:

    • getEntry

      Object getEntry(String component, String name, Class type, Object defaultValue) throws ConfigurationException
      Returns an object of the specified type created using the information in the entry matching the specified component and name, and supplying no data, returning the default value if no matching entry is found and the default value is not NO_DEFAULT. If type is a primitive type, then the result is returned as an instance of the associated wrapper class. Repeated calls with the same arguments may or may not return the identical object.

      The component identifies the object whose behavior will be configured using the object returned. The value of component must be a QualifiedIdentifier, as defined in the Java Language Specification (JLS), and is typically the class or package name of the object being configured. The name identifies which of possibly several entries are available for the given component. The value of name must be an Identifier, as defined in the JLS.

      Calling this method is equivalent to calling getEntry(component, name, type, defaultValue, NO_DATA).

      Parameters:
      component - the component being configured
      name - the name of the entry for the component
      type - the type of the object to be returned
      defaultValue - the object to return if no matching entry is found, or NO_DEFAULT to specify no default
      Returns:
      an object created using the information in the entry matching component and name, or defaultValue if no matching entry is found and defaultValue is not NO_DEFAULT
      Throws:
      NoSuchEntryException - if no matching entry is found and defaultValue is NO_DEFAULT
      ConfigurationException - if a matching entry is found but a problem occurs creating the object for the entry, or if type is a reference type and the result for the matching entry is not either null or an instance of type, or if type is a primitive type and the result is not an instance of the associated wrapper class. Any Error thrown while creating the object is propagated to the caller; it is not wrapped in a ConfigurationException.
      IllegalArgumentException - if component is not null and is not a valid QualifiedIdentifier; or if name is not null and is not a valid Identifier; or if type is a reference type and defaultValue is not NO_DEFAULT, null, or an instance of type; or if type is a primitive type and defaultValue is not NO_DEFAULT or an instance of the associated wrapper class
      NullPointerException - if component, name, or type is null
      See Also:

    • getEntry

      Object getEntry(String component, String name, Class type, Object defaultValue, Object data) throws ConfigurationException
      Returns an object of the specified type created using the information in the entry matching the specified component and name, and using the specified data (unless it is NO_DATA), returning the default value if no matching entry is found and the default value is not NO_DEFAULT. If type is a primitive type, then the result is returned as an instance of the associated wrapper class. Repeated calls with the same arguments may or may not return the identical object.

      The component identifies the object whose behavior will be configured using the object returned. The value of component must be a QualifiedIdentifier, as defined in the Java Language Specification (JLS), and is typically the class or package name of the object being configured. The name identifies which of possibly several entries are available for the given component. The value of name must be an Identifier, as defined in the JLS.

      Parameters:
      component - the component being configured
      name - the name of the entry for the component
      type - the type of the object to be returned
      defaultValue - the object to return if no matching entry is found, or NO_DEFAULT to specify no default
      data - an object to use when computing the value of the entry, or NO_DATA to specify no data
      Returns:
      an object created using the information in the entry matching component and name, and using the value of data (unless it is NO_DATA), or defaultValue if no matching entry is found and defaultValue is not NO_DEFAULT
      Throws:
      NoSuchEntryException - if no matching entry is found and defaultValue is NO_DEFAULT
      ConfigurationException - if a matching entry is found but a problem occurs creating the object for the entry, or if type is a reference type and the result for the matching entry is not either null or an instance of type, or if type is a primitive type and the result is not an instance of the associated wrapper class. Any Error thrown while creating the object is propagated to the caller; it is not wrapped in a ConfigurationException.
      IllegalArgumentException - if component is not null and is not a valid QualifiedIdentifier; or if name is not null and is not a valid Identifier; or if type is a reference type and defaultValue is not NO_DEFAULT, null, or an instance of type; or if type is a primitive type and defaultValue is not NO_DEFAULT or an instance of the associated wrapper class
      NullPointerException - if component, name, or type is null