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copied!<p>You can make your object comparable:</p> <pre><code>public static class MyObject implements Comparable<MyObject> { private Date dateTime; public Date getDateTime() { return dateTime; } public void setDateTime(Date datetime) { this.dateTime = datetime; } @Override public int compareTo(MyObject o) { return getDateTime().compareTo(o.getDateTime()); } } </code></pre> <p>And then you sort it by calling:</p> <pre><code>Collections.sort(myList); </code></pre> <p>However sometimes you don't want to change your model, like when you want to sort on several different properties. In that case, you can create comparator on the fly:</p> <pre><code>Collections.sort(myList, new Comparator<MyObject>() { public int compare(MyObject o1, MyObject o2) { return o1.getDateTime().compareTo(o2.getDateTime()); } }); </code></pre> <p>However, the above works only if you're certain that dateTime is not null at the time of comparison. It's wise to handle null as well to avoid NullPointerExceptions:</p> <pre><code>public static class MyObject implements Comparable<MyObject> { private Date dateTime; public Date getDateTime() { return dateTime; } public void setDateTime(Date datetime) { this.dateTime = datetime; } @Override public int compareTo(MyObject o) { if (getDateTime() == null || o.getDateTime() == null) return 0; return getDateTime().compareTo(o.getDateTime()); } } </code></pre> <p>Or in the second example:</p> <pre><code>Collections.sort(myList, new Comparator<MyObject>() { public int compare(MyObject o1, MyObject o2) { if (o1.getDateTime() == null || o2.getDateTime() == null) return 0; return o1.getDateTime().compareTo(o2.getDateTime()); } }); </code></pre>

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