org.aoju.bus.core.lang

Class WeightRandom<T>

java.lang.Object

org.aoju.bus.core.lang.WeightRandom<T>

Type Parameters:

T - 权重随机获取的对象类型

All Implemented Interfaces:

Serializable

public class WeightRandom<T>
extends Object
implements Serializable

权重随机算法实现

平时，经常会遇到权重随机算法，从不同权重的N个元素中随机选择一个，并使得总体选择结果是按照权重分布的。如广告投放、负载均衡等。

如有4个元素A、B、C、D，权重分别为1、2、3、4，随机结果中A:B:C:D的比例要为1:2:3:4。

总体思路：累加每个元素的权重A(1)-B(3)-C(6)-D(10)，则4个元素的的权重管辖区间分别为[0,1)、[1,3)、[3,6)、[6,10)。 然后随机出一个[0,10)之间的随机数。落在哪个区间，则该区间之后的元素即为按权重命中的元素。

Since:

JDK 1.8

Version:

3.2.5

Author:

Kimi Liu

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	WeightRandom.WeightObj<T> 带有权重的对象包装

Constructor Summary

Constructors

Constructor and Description
WeightRandom() 构造
WeightRandom(Iterable<WeightRandom.WeightObj<T>> weightObjs) 构造
WeightRandom(WeightRandom.WeightObj<T> weightObj) 构造
WeightRandom(WeightRandom.WeightObj<T>[] weightObjs) 构造

Method Summary

Modifier and Type	Method and Description
WeightRandom<T>	add(T obj, double weight) 增加对象
WeightRandom<T>	add(WeightRandom.WeightObj<T> weightObj) 增加对象权重
WeightRandom<T>	clear() 清空权重表
static <T> WeightRandom<T>	create() 创建权重随机获取器
T	next() 下一个随机对象

Methods inherited from class java.lang.Object

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

Constructor Detail

WeightRandom

public WeightRandom()

构造

WeightRandom

public WeightRandom(WeightRandom.WeightObj<T> weightObj)

构造

Parameters:

weightObj - 带有权重的对象

WeightRandom

public WeightRandom(Iterable<WeightRandom.WeightObj<T>> weightObjs)

构造

Parameters:

weightObjs - 带有权重的对象

WeightRandom

public WeightRandom(WeightRandom.WeightObj<T>[] weightObjs)

构造

Parameters:

weightObjs - 带有权重的对象

Method Detail

create

public static <T> WeightRandom<T> create()

创建权重随机获取器

Type Parameters:

T - 对象

Returns:

WeightRandom

add

public WeightRandom<T> add(T obj,
                           double weight)

增加对象

Parameters:

obj - 对象

weight - 权重

Returns:

this

add

public WeightRandom<T> add(WeightRandom.WeightObj<T> weightObj)

增加对象权重

Parameters:

weightObj - 权重对象

Returns:

this

clear

public WeightRandom<T> clear()

清空权重表

Returns:

this

next

public T next()

下一个随机对象

Returns:

随机对象