blocks|key|692560|text|这是你的list的一种方法|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|692561|list.sort(null);
Collections.reverse(list);|code-block|syntax|javascript|692562|或者，您可以实现自己的Comparator来进行排序并消除相反的步骤：|692563|list.sort((o1,+o2)+->+o2.compareTo(o1));|692564|或者更简单地使用Collections.reverseOrder()，因为您只是在反转：|692565|list.sort(Collections.reverseOrder());|692566|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javase/6/docs/api/java/util/Comparator.html|1|http://download.oracle.com/javase/6/docs/api/java/util/Collections.html#reverseOrder%2528%2529^0|4|4|0|0|B|A|B|A|0|0|0|8|Q|8|Q|1|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@$9|13|A|14|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|15|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|16|8|@$9|17|A|18|B|C]]|D|@$9|19|A|1A|1|1B]]|E|$]]|$1|M|3|N|5|H|7|1C|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1D|8|@$9|1E|A|1F|B|C]]|D|@$9|1G|A|1H|1|1I]]|E|$]]|$1|Q|3|R|5|H|7|1J|8|@]|D|@]|E|$I|J]]|$1|S|3|-4|5|6|7|1K|8|@]|D|@]|E|$]]]|T|$U|$5|V|W|X|E|$Y|Z]]|10|$5|V|W|X|E|$Y|11]]]]

Here's one way for your <code>list</code>:

<pre><code>list.sort(null);
Collections.reverse(list);
</code></pre>

Or you could implement your own <a href="http://download.oracle.com/javase/6/docs/api/java/util/Comparator.html" rel="noreferrer"><code>Comparator</code></a> to sort on and eliminate the reverse step:

<pre><code>list.sort((o1, o2) -&gt; o2.compareTo(o1));
</code></pre>

Or even more simply use <a href="http://download.oracle.com/javase/6/docs/api/java/util/Collections.html#reverseOrder%28%29" rel="noreferrer"><code>Collections.reverseOrder()</code></a> since you're only reversing:

<pre><code>list.sort(Collections.reverseOrder());
</code></pre>

blocks|key|908707|text|Comparator<Long>+comparator+=+Collections.reverseOrder();
Collections.sort(arrayList,+comparator);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|908708|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>Comparator&lt;Long&gt; comparator = Collections.reverseOrder();
Collections.sort(arrayList, comparator);
</code></pre>

blocks|key|692767|text|你可以使用下面给出的代码；|type|unstyled|depth|inlineStyleRanges|entityRanges|data|692768|Collections.sort(list,+Collections.reverseOrder());|code-block|syntax|javascript|692769|或者，如果您要使用自定义比较器，则可以使用下面给出的方法|692770|Collections.sort(list,+Collections.reverseOrder(new+CustomComparator());|692771|其中CustomComparator是一个比较器类，用于比较列表中存在的对象。|692772|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

You can use the following code which is given below;

<pre><code>Collections.sort(list, Collections.reverseOrder());
</code></pre>

or if you are going to use custom comparator you can use as it is given below

<pre><code>Collections.sort(list, Collections.reverseOrder(new CustomComparator());
</code></pre>

Where CustomComparator is a comparator class that compares the object which is present in the list.

blocks|key|692494|text|正常排序并使用Collections.reverse();|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|692495|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javase/6/docs/api/java/util/Collections.html#reverse%2528java.util.List%2529^0|7|M|7|M|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]]|D|@$9|Q|A|R|1|S]]|E|$]]|$1|F|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

Sort normally and use <a href="http://download.oracle.com/javase/6/docs/api/java/util/Collections.html#reverse%28java.util.List%29" rel="nofollow"><code>Collections.reverse();</code></a>

blocks|key|908856|text|对于lamdas，其中您的长值位于对象中的某个位置，我建议使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|908857|.sorted((o1,+o2)+->+Long.compare(o1.getLong(),+o2.getLong()))|code-block|syntax|javascript|908858|或者更好：|908859|.sorted(Comparator.comparingLong(MyObject::getLong))|908860|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

For lamdas where your long value is somewhere in an object I recommend using:

<pre><code>.sorted((o1, o2) -&gt; Long.compare(o1.getLong(), o2.getLong()))
</code></pre>

or even better: 

<pre><code>.sorted(Comparator.comparingLong(MyObject::getLong))
</code></pre>

blocks|key|908510|text|排序，然后反转。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|908511|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

blocks|key|908680|text|通过将Collections.sort()与提供递减顺序的比较器一起使用。请参阅Collections.sort的Javadoc。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|908681|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javase/6/docs/api/java/util/Collections.html#sort%2528java.util.List,%2520java.util.Comparator%2529^0|3|I|14|G|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]]|D|@$9|Q|A|R|1|S]]|E|$]]|$1|F|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

By using <code>Collections.sort()</code> with a comparator that provides the decreasing order.
See Javadoc for <a href="http://download.oracle.com/javase/6/docs/api/java/util/Collections.html#sort%28java.util.List,%20java.util.Comparator%29" rel="nofollow">Collections.sort</a>.

blocks|key|692695|text|实现我们自己的比较器的更通用的方法，如下所示|type|unstyled|depth|inlineStyleRanges|entityRanges|data|692696|Collections.sort(lst,new+Comparator<Long>(){
++++++++++++++++public+int+compare(Long+o1,+Long+o2)+{
++++++++++++++++++++return+o2.compareTo(o1);
++++++++++++++++}
++++++++++++});|code-block|syntax|javascript|692697|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

A more general approach to implement our own Comparator as below

<pre><code>Collections.sort(lst,new Comparator&lt;Long&gt;(){
 public int compare(Long o1, Long o2) {
 return o2.compareTo(o1);
 }
 });
</code></pre>

blocks|key|908897|text|所以，我想提出一些我认为很重要的事情，我认为你应该考虑一下。运行时和内存。假设你有一个列表，想要对它进行排序，那么你可以，有一个内置的排序，或者你可以开发自己的排序。然后你会说，想要颠倒这个列表。这就是上面列出的答案。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|908898|但是，如果您正在创建该列表，最好使用不同的数据结构来存储它，然后将其转储到一个数组中。|908899|堆就是这样做的。你过滤数据，它会处理所有东西，然后你可以从对象中弹出所有东西，然后它就会被排序。|908900|另一种选择是理解地图是如何工作的。很多时候，地图或HashMap作为事物的名称，背后都有一个潜在的概念。|908901|例如..。您输入一组键-值对，其中键是最长的，当您添加所有元素时，您可以这样做：.keys，它将自动向您返回一个排序列表。|offset|length|style|CODE|908902|这取决于您之前如何处理数据，我认为您应该如何继续进行排序和随后的冲销|908903|entityMap^0|0|0|0|0|14|5|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|T|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|U|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|V|8|@$J|W|K|X|L|M]]|9|@]|A|$]]|$1|N|3|O|5|6|7|Y|8|@]|9|@]|A|$]]|$1|P|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|Q|$]]

So, There is something I would like to bring up which I think is important and I think that you should consider. runtime and memory. Say you have a list and want to sort it, well you can, there is a built in sort or you could develop your own. Then you say, want to reverse the list. That is the answer which is listed above.

If you are creating that list though, it might be good to use a different datastructure to store it and then just dump it into an array.

Heaps do just this. You filter in data, and it will handle everything, then you can pop everything off of the object and it would be sorted.

Another option would be to understand how maps work. A lot of times, a Map or HashMap as something things are called, have an underlying concept behind it.

For example.... you feed in a bunch of key-value pairs where the key is the long, and when you add all the elements, you can do: <code>.keys</code> and it would return to you a sorted list automatically.

It depends on how you process the data prior as to how i think you should continue with your sorting and subsequent reverses

blocks|key|908936|text|可以使用比较器的比较方法来比较对象，然后可以应用方法reversed()来反转顺序-|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|908937|list.stream().sorted(Comparator.comparing(Employee::getName).reversed()).collect(toList());|code-block|syntax|javascript|908938|entityMap^0|Q|A|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

Comparator's comparing method can be used to compare the objects and then method <code>reversed()</code> can be applied to reverse the order - 

<pre><code>list.stream().sorted(Comparator.comparing(Employee::getName).reversed()).collect(toList());
</code></pre>

blocks|key|692919|text|使用List.sort()和Comparator.comparingLong()|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|692920|numberList.sort(Comparator.comparingLong(x+->+-x));|code-block|syntax|javascript|692921|entityMap^0|2|B|E|Q|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

Using <code>List.sort()</code> and <code>Comparator.comparingLong()</code>
<pre><code>numberList.sort(Comparator.comparingLong(x -&gt; -x));
</code></pre>

How to sort an <code>ArrayList&lt;Long&gt;</code> in Java in decreasing order?

How to sort ArrayList<Long> in decreasing order?

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