# Interface Control

All Superinterfaces:
  `Serializable`

All Known Implementing Classes:
  `BasicControl, ManageReferralControl, PagedResultsControl, PagedResultsResponseControl, SortControl, SortResponseControl`

public interface Control extends Serializable
This interface represents an LDAPv3 control as defined in RFC 2251.

The LDAPv3 protocol uses controls to send and receive additional data to affect the behavior of predefined operations. Controls can be sent along with any LDAP operation to the server. These are referred to as request controls. For example, a "sort" control can be sent with an LDAP search operation to request that the results be returned in a particular order. Solicited and unsolicited controls can also be returned with responses from the server. Such controls are referred to as response controls. For example, an LDAP server might define a special control to return change notifications.

This interface is used to represent both request and response controls.

Since:
  1.3
See Also:
  - `ControlFactory`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final boolean`
  `CRITICAL`
  Indicates a critical control.
  `static final boolean`
  `NONCRITICAL`
  Indicates a non-critical control.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `byte[]`
  `getEncodedValue()`
  Retrieves the ASN.1 BER encoded value of the LDAP control.
  `String`
  `getID()`
  Retrieves the object identifier assigned for the LDAP control.
  `boolean`
  `isCritical()`
  Determines the criticality of the LDAP control.

- ## Field Details

  - ### CRITICAL

    static final boolean CRITICAL
    Indicates a critical control. The value of this constant is `true`.
    See Also:
      - Constant Field Values

  - ### NONCRITICAL

    static final boolean NONCRITICAL
    Indicates a non-critical control. The value of this constant is `false`.
    See Also:
      - Constant Field Values

- ## Method Details

  - ### getID

    String getID()
    Retrieves the object identifier assigned for the LDAP control.
    Returns:
      The non-null object identifier string.

  - ### isCritical

    boolean isCritical()
    Determines the criticality of the LDAP control. A critical control must not be ignored by the server. In other words, if the server receives a critical control that it does not support, regardless of whether the control makes sense for the operation, the operation will not be performed and an `OperationNotSupportedException` will be thrown.
    Returns:
      true if this control is critical; false otherwise.

  - ### getEncodedValue

    byte[] getEncodedValue()
    Retrieves the ASN.1 BER encoded value of the LDAP control. The result is the raw BER bytes including the tag and length of the control's value. It does not include the controls OID or criticality. Null is returned if the value is absent.
    Returns:
      A possibly null byte array representing the ASN.1 BER encoded value of the LDAP control.