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copied!<p>Another good way of doing this that is a bit more flexible if there is more than one property of an object that you may wish to sort by is to use <a href="http://code.google.com/p/guava-libraries/" rel="nofollow noreferrer">Guava</a>'s <a href="https://google.github.io/guava/releases/snapshot/api/docs/com/google/common/collect/Ordering.html" rel="nofollow noreferrer">Ordering</a> class with its <code>onResultOf(Function)</code> option. This is ideally suited for sorting by properties since a <a href="http://guava-libraries.googlecode.com/svn/trunk/javadoc/com/google/common/base/Function.html" rel="nofollow noreferrer">Function</a> can be used to retrieve and return a specific property of an object. For a simple example, imagine a class <code>Person</code> with <code>String getFirstName()</code> and <code>String getLastName()</code> methods.</p> <pre><code>List<Person> people = ...; Collections.sort(people, Ordering.natural().onResultOf( new Function<Person, String>() { public String apply(Person from) { return from.getFirstName(); } })); </code></pre> <p>The above will sort the list by first name.</p> <p>To make it read nicer, you may want to define the functions you might want to use as <code>public static final</code> fields on the <code>Person</code> class. Then you could sort by last name like this:</p> <pre><code>Collections.sort(people, Ordering.natural().onResultOf(Person.GET_LAST_NAME)); </code></pre> <p>As a fun aside note, this will all be a lot easier in Java 8 with lambda expressions and method references. You'll be able to write something like this without having to define any clumsy anonymous inner classes or static final fields:</p> <pre><code>import static java.util.Comparator.comparing; ... people.sort(comparing(Person::getLastName)); </code></pre>

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