程序包 ohos.utils

类 ObjectAttribute<O,T>

java.lang.Object

ohos.utils.ObjectAttribute<O,T>

public abstract class ObjectAttribute<O,T>
extends Object

An abstract class of object attributes.

The ObjectAttribute class has the following characteristics:

• You can override the get(java.lang.Object) and set(java.lang.Object,java.lang.Object) methods to implement general-purpose setter and getter methods, thereby making the code cleaner.
• References to object attributes are flattened. For example, object A needs to hold a reference to object B to access one of its attributes, but object B has multiple other attributes that should be hidden from object A. In this case, you can use the ObjectAttribute class to encapsulate only the accessible attribute of object B and transfer it to object A.
• You can override the set(java.lang.Object,java.lang.Object) method to set an object attribute to read-only.

从以下版本开始:

2

构造器概要

构造器

构造器	说明
ObjectAttribute(Class<T> attrType, String attrName)	A constructor used to create an ObjectAttribute instance based on the specified attribute type and name.

方法概要

限定符和类型	方法	说明
abstract T	get(O obj)	Obtains the attribute value of a specified object.
Class<T>	getAttrType()	Obtains the type of the attribute encapsulated in the current ObjectAttribute object.
String	getName()	Obtains the name of the attribute encapsulated in the current ObjectAttribute object.
boolean	isReadOnly()	Checks whether the attribute encapsulated in the current ObjectAttribute object is read-only.
void	set(O obj, T value)	Sets the attribute value of a specified object.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

ObjectAttribute

public ObjectAttribute(Class<T> attrType,
                       String attrName)

A constructor used to create an ObjectAttribute instance based on the specified attribute type and name.

参数:

attrType - Indicates the type of the object attribute.

attrName - Indicates the name of the object attribute.

方法详细资料

get

public abstract T get(O obj)

Obtains the attribute value of a specified object. This attribute is the one encapsulated in the current ObjectAttribute object.

参数:

obj - Indicates the object to be accessed.

返回:

Returns the value of the attribute encapsulated in the current ObjectAttribute object.

set

public void set(O obj,
                T value)

Sets the attribute value of a specified object. This attribute is the one encapsulated in the current ObjectAttribute object.

参数:

obj - Indicates the object to be accessed.

value - Indicates the attribute value to set.

isReadOnly

public boolean isReadOnly()

Checks whether the attribute encapsulated in the current ObjectAttribute object is read-only.

If true is returned, an UnsupportedOperationException exception will be thrown when you call the set(java.lang.Object,java.lang.Object) method.

返回:

Returns true if the attribute is read-only, indicating that the attribute value cannot be updated by the set(java.lang.Object,java.lang.Object) method.

getName

public String getName()

Obtains the name of the attribute encapsulated in the current ObjectAttribute object.

返回:

Returns a string representing the attribute name.

getAttrType

public Class<T> getAttrType()

Obtains the type of the attribute encapsulated in the current ObjectAttribute object.

返回:

Returns the type of the attribute encapsulated in the current ObjectAttribute object.