org.joda.beans
Interface MetaBean

All Known Subinterfaces:

DynamicMetaBean

All Known Implementing Classes:

BasicMetaBean, DirectMetaBean, ReflectiveMetaBean

public interface MetaBean

A meta-bean, defining those aspects of a bean which are not specific to a particular instance, such as the type and set of meta-properties.

This interface can be thought of as the equivalent of Class but for beans. In most cases the meta-bean will be code generated and the concrete class will have additional methods.

builder

BeanBuilder<? extends Bean> builder()

Creates a bean builder that can be used to create an instance of this bean.

The builder is used in two main ways. The first is to allow immutable beans to be constructed. The second is to enable automated tools like serialization/deserialization.

The builder can be thought of as a Map of MetaProperty to value. Note that the implementation is not necessarily an actual map.

Returns:

the bean builder, not null

Throws:

UnsupportedOperationException - if the bean cannot be created

createPropertyMap

PropertyMap createPropertyMap(Bean bean)

Creates a map of properties for the specified bean.

This allows the entire set of properties of the bean to be exposed as a Map. The map is keyed by the property name and has Property instances as values. Call PropertyMap.flatten() to convert the map to hold the actual values from the bean.

Parameters:

bean - the bean to create the map for, not null

Returns:

the created property map, not null

beanName

String beanName()

Gets the bean name, which is normally the fully qualified class name of the bean.

This is primarily used for human-readable output.

Returns:

the name of the bean, not empty

beanType

Class<? extends Bean> beanType()

Get the type of the bean, represented as a Class.

A MetaBean can be thought of as the equivalent of Class but for beans. This method allows the actual Class instance of the bean to be obtained.

Returns:

the type of the bean, not null

metaPropertyCount

int metaPropertyCount()

Counts the number of properties.

Each meta-bean manages a single bean with a known set of properties. This method returns the count of properties.

Returns:

the number of properties

metaPropertyExists

boolean metaPropertyExists(String propertyName)

Checks if a property exists.

Each meta-bean manages a single bean with a known set of properties. This method checks whether there is a property with the specified name.

Parameters:

propertyName - the property name to check, null returns false

Returns:

true if the property exists

metaProperty

<R> MetaProperty<R> metaProperty(String propertyName)

Gets a meta-property by name.

Each meta-bean manages a single bean with a known set of properties. This method returns the property with the specified name.

The base interface throws an exception if the name is not recognised. By contrast, the DynamicMetaBean subinterface creates the property on demand.

Type Parameters:

R - the property type, optional, enabling auto-casting

Parameters:

propertyName - the property name to retrieve, not null

Returns:

the meta property, not null

Throws:

NoSuchElementException - if the property name is invalid

metaPropertyIterable

Iterable<MetaProperty<?>> metaPropertyIterable()

Gets an iterator of meta-properties.

This method returns an Iterable, which is simpler than a Map. As a result, implementations may be able to optimise, and so this method should be preferred to metaPropertyMap() where a choice is possible.

Returns:

the unmodifiable map of meta property objects, not null

metaPropertyMap

Map<String,MetaProperty<?>> metaPropertyMap()

Gets the map of meta-properties, keyed by property name.

Where possible, use metaPropertyIterable() instead as it typically has better performance.

Returns:

the unmodifiable map of meta property objects, not null