java - How do I sort an ArrayList based on its object's contents - Stack Overflow

ArrayList<Person> people = . . .;  Collections.sort(people, new Comparator<Person>() {          @Override          public int compare(Person o1, Person o2) {              final int age1 = o1.getAge();              final int age2 = o2.getAge();              return age1 < age2 ? -1 : age1 > age2 ? 1 : 0;          }      }  );

In Java 7, you can use return Integer.compare(age1, age2); instead.

Alternatively, you can have Person implement Comparable<Person>. However, then you could only sort on the one attribute.

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