Lambda表达式九：补充二：Stream接口的sorted()方法，Comparator函数式接口效果展示；Comparator函数式接口；函数式接口严格规范；

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我是靠谱客的博主真实服饰，最近开发中收集的这篇文章主要介绍Lambda表达式九：补充二：Stream接口的sorted()方法，Comparator函数式接口效果展示；Comparator函数式接口；函数式接口严格规范；，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

本篇博客，主要是解决Lambda表达式九：Stream流三：Stream常用方法；的一个模糊的点，是对那篇文章中的一个补充。

本篇博客没什么，主要就是加深下对Comparator接口的了解。

1.Stream接口的sorted()方法，Comparator函数式接口效果展示；

2.Comparetor函数式接口的简述（本部分转载自8.函数式接口Comparator）

1.Stream接口的sorted()方法，Comparator函数式接口效果展示；

Comparator接口中的核心方法，compare方法源码内容：

    /**
     * Compares its two arguments for order.  Returns a negative integer,
     * zero, or a positive integer as the first argument is less than, equal
     * to, or greater than the second.<p>
     *
     * In the foregoing description, the notation
     * <tt>sgn(</tt><i>expression</i><tt>)</tt> designates the mathematical
     * <i>signum</i> function, which is defined to return one of <tt>-1</tt>,
     * <tt>0</tt>, or <tt>1</tt> according to whether the value of
     * <i>expression</i> is negative, zero or positive.<p>
     *
     * The implementor must ensure that <tt>sgn(compare(x, y)) ==
     * -sgn(compare(y, x))</tt> for all <tt>x</tt> and <tt>y</tt>.  (This
     * implies that <tt>compare(x, y)</tt> must throw an exception if and only
     * if <tt>compare(y, x)</tt> throws an exception.)<p>
     *
     * The implementor must also ensure that the relation is transitive:
     * <tt>((compare(x, y)&gt;0) &amp;&amp; (compare(y, z)&gt;0))</tt> implies
     * <tt>compare(x, z)&gt;0</tt>.<p>
     *
     * Finally, the implementor must ensure that <tt>compare(x, y)==0</tt>
     * implies that <tt>sgn(compare(x, z))==sgn(compare(y, z))</tt> for all
     * <tt>z</tt>.<p>
     *
     * It is generally the case, but <i>not</i> strictly required that
     * <tt>(compare(x, y)==0) == (x.equals(y))</tt>.  Generally speaking,
     * any comparator that violates this condition should clearly indicate
     * this fact.  The recommended language is "Note: this comparator
     * imposes orderings that are inconsistent with equals."
     *
     * @param o1 the first object to be compared.
     * @param o2 the second object to be compared.
     * @return a negative integer, zero, or a positive integer as the
     *         first argument is less than, equal to, or greater than the
     *         second.
     * @throws NullPointerException if an argument is null and this
     *         comparator does not permit null arguments
     * @throws ClassCastException if the arguments' types prevent them from
     *         being compared by this comparator.
     */
    int compare(T o1, T o2);