BeanInfo (Java SE 17 & JDK 17)
Description: declaration: module: java.desktop, package: java.beans, interface: BeanInfo
Keywords: java.beans.BeanInfo interface

Module java.desktop
Package java.beans

# Interface BeanInfo

All Known Subinterfaces:
  `BeanContextServiceProviderBeanInfo`

All Known Implementing Classes:
  `SimpleBeanInfo`

public interface BeanInfo
Use the `BeanInfo` interface to create a `BeanInfo` class and provide explicit information about the methods, properties, events, and other features of your beans.

When developing your bean, you can implement the bean features required for your application task omitting the rest of the `BeanInfo` features. They will be obtained through the automatic analysis by using the low-level reflection of the bean methods and applying standard design patterns. You have an opportunity to provide additional bean information through various descriptor classes.

See the `SimpleBeanInfo` class that is a convenient basic class for `BeanInfo` classes. You can override the methods and properties of the `SimpleBeanInfo` class to define specific information.

See also the `Introspector` class to learn more about bean behavior.

Since:
  1.1

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final int`
  `ICON_COLOR_16x16`
  Constant to indicate a 16 x 16 color icon.
  `static final int`
  `ICON_COLOR_32x32`
  Constant to indicate a 32 x 32 color icon.
  `static final int`
  `ICON_MONO_16x16`
  Constant to indicate a 16 x 16 monochrome icon.
  `static final int`
  `ICON_MONO_32x32`
  Constant to indicate a 32 x 32 monochrome icon.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `BeanInfo[]`
  `getAdditionalBeanInfo()`
  This method enables the current `BeanInfo` object to return an arbitrary collection of other `BeanInfo` objects that provide additional information about the current bean.
  `BeanDescriptor`
  `getBeanDescriptor()`
  Returns the bean descriptor that provides overall information about the bean, such as its display name or its customizer.
  `int`
  `getDefaultEventIndex()`
  A bean may have a default event typically applied when this bean is used.
  `int`
  `getDefaultPropertyIndex()`
  A bean may have a default property commonly updated when this bean is customized.
  `EventSetDescriptor[]`
  `getEventSetDescriptors()`
  Returns the event descriptors of the bean that define the types of events fired by this bean.
  `Image`
  `getIcon(int iconKind)`
  Returns an image that can be used to represent the bean in toolboxes or toolbars.
  `MethodDescriptor[]`
  `getMethodDescriptors()`
  Returns the method descriptors of the bean that define the externally visible methods supported by this bean.
  `PropertyDescriptor[]`
  `getPropertyDescriptors()`
  Returns descriptors for all properties of the bean.

- ## Field Details

  - ### ICON_COLOR_16x16

    static final int ICON_COLOR_16x16
    Constant to indicate a 16 x 16 color icon.
    See Also:
      - Constant Field Values

  - ### ICON_COLOR_32x32

    static final int ICON_COLOR_32x32
    Constant to indicate a 32 x 32 color icon.
    See Also:
      - Constant Field Values

  - ### ICON_MONO_16x16

    static final int ICON_MONO_16x16
    Constant to indicate a 16 x 16 monochrome icon.
    See Also:
      - Constant Field Values

  - ### ICON_MONO_32x32

    static final int ICON_MONO_32x32
    Constant to indicate a 32 x 32 monochrome icon.
    See Also:
      - Constant Field Values

- ## Method Details

  - ### getBeanDescriptor

    BeanDescriptor getBeanDescriptor()
    Returns the bean descriptor that provides overall information about the bean, such as its display name or its customizer.
    Returns:
      a `BeanDescriptor` object, or `null` if the information is to be obtained through the automatic analysis

  - ### getEventSetDescriptors

    EventSetDescriptor[] getEventSetDescriptors()
    Returns the event descriptors of the bean that define the types of events fired by this bean.
    Returns:
      an array of `EventSetDescriptor` objects, or `null` if the information is to be obtained through the automatic analysis

  - ### getDefaultEventIndex

    int getDefaultEventIndex()
    A bean may have a default event typically applied when this bean is used.
    Returns:
      index of the default event in the `EventSetDescriptor` array returned by the `getEventSetDescriptors` method, or -1 if there is no default event

  - ### getPropertyDescriptors

    PropertyDescriptor[] getPropertyDescriptors()
    Returns descriptors for all properties of the bean.

    If a property is indexed, then its entry in the result array belongs to the `IndexedPropertyDescriptor` subclass of the `PropertyDescriptor` class. A client of the `getPropertyDescriptors` method can use the `instanceof` operator to check whether a given `PropertyDescriptor` is an `IndexedPropertyDescriptor`.

    Returns:
      an array of `PropertyDescriptor` objects, or `null` if the information is to be obtained through the automatic analysis

  - ### getDefaultPropertyIndex

    int getDefaultPropertyIndex()
    A bean may have a default property commonly updated when this bean is customized.
    Returns:
      index of the default property in the `PropertyDescriptor` array returned by the `getPropertyDescriptors` method, or -1 if there is no default property

  - ### getMethodDescriptors

    MethodDescriptor[] getMethodDescriptors()
    Returns the method descriptors of the bean that define the externally visible methods supported by this bean.
    Returns:
      an array of `MethodDescriptor` objects, or `null` if the information is to be obtained through the automatic analysis

  - ### getAdditionalBeanInfo

    BeanInfo[] getAdditionalBeanInfo()
    This method enables the current `BeanInfo` object to return an arbitrary collection of other `BeanInfo` objects that provide additional information about the current bean.

    If there are conflicts or overlaps between the information provided by different `BeanInfo` objects, the current `BeanInfo` object takes priority over the additional `BeanInfo` objects. Array elements with higher indices take priority over the elements with lower indices.

    Returns:
      an array of `BeanInfo` objects, or `null` if there are no additional `BeanInfo` objects

  - ### getIcon

    Image getIcon(int iconKind)
    Returns an image that can be used to represent the bean in toolboxes or toolbars.

    There are four possible types of icons: 16 x 16 color, 32 x 32 color, 16 x 16 mono, and 32 x 32 mono. If you implement a bean so that it supports a single icon, it is recommended to use 16 x 16 color. Another recommendation is to set a transparent background for the icons.

    Parameters:
      `iconKind` - the kind of icon requested
    Returns:
      an image object representing the requested icon, or `null` if no suitable icon is available
    See Also:
      - `ICON_COLOR_16x16`
      - `ICON_COLOR_32x32`
      - `ICON_MONO_16x16`
      - `ICON_MONO_32x32`