Java相关排序

1、If
it is a collection, use Collections.sort() method.

// Collections.sort
List<ObjectName> list = new ArrayList<ObjectName>();
Collections.sort(list, new Comparator<ObjectName>() {
public int compare(ObjectName o1, ObjectName o2) {
return o1.toString().compareTo(o2.toString());
}
});2、If
it is an array, use 

Arrays.sort()

 method.
// Arrays.sort
ObjectName[] arr = new ObjectName[10];
Arrays.sort(arr, new Comparator<ObjectName>() {
public int compare(ObjectName o1, ObjectName o2) {
return o1.toString().compareTo(o2.toString());
}
});If
it is a list or set, use 

TreeSet

 to
sort.
// TreeSet
Set<ObjectName> sortedSet = new TreeSet<ObjectName>(new Comparator<ObjectName>() {
public int compare(ObjectName o1, ObjectName o2) {
return o1.toString().compareTo(o2.toString());
}
});
sortedSet.addAll(unsortedSet);If
it is a map, use 

TreeMap

 to
sort. 

TreeMap

 is
sorted by key.
// TreeMap - using String.CASE_INSENSITIVE_ORDER which is a Comparator that orders Strings by compareToIgnoreCase
Map<String, Integer> sortedMap = new TreeMap<String, Integer>(String.CASE_INSENSITIVE_ORDER);
sortedMap.putAll(unsortedMap);

//TreeMap - In general, defined comparator
Map<ObjectName, String> sortedMap = new TreeMap<ObjectName, String>(new Comparator<ObjectName>() {
public int compare(ObjectName o1, ObjectName o2) {
return o1.toString().compareTo(o2.toString());
}
});
sortedMap.putAll(unsortedMap);

http://www.programcreek.com/2014/03/how-developers-sort-in-java/