程序包 ohos.media.common

类 Format.Key<T>

java.lang.Object

ohos.media.common.Format.Key<T>

类型参数:

T - Indicates the data type of a property key value.

封闭类:

Format

public static final class Format.Key<T>
extends Object

Defines types of codec property keys.

从以下版本开始:

6

方法概要

限定符和类型	方法	说明
boolean	equals(Object key)	Indicates whether some other object is "equal to" this one.
int	hashCode()	Returns a hash code value for the object.
String	toString()	Returns a string representation of the object.

从类继承的方法 java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

方法详细资料

equals

public boolean equals(Object key)

从类复制的说明: Object

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
• For any non-null reference value x, x.equals(null) should return false.

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

覆盖:

equals 在类中 Object

参数:

key - the reference object with which to compare.

返回:

true if this object is the same as the obj argument; false otherwise.

另请参阅:

Object.hashCode(), HashMap

hashCode

public int hashCode()

从类复制的说明: Object

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

The general contract of hashCode is:

• Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
• If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
• It is not required that if two objects are unequal according to the Object.equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java™ programming language.)

覆盖:

hashCode 在类中 Object

返回:

a hash code value for this object.

另请参阅:

Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

toString

public String toString()

从类复制的说明: Object

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())
 

覆盖:

toString 在类中 Object

返回:

a string representation of the object.