java利用set给数组去重

hashSet 无序

treeSet 有序（对数据按其默认排序方式，进行排序）

@Test
public void test() throws Exception {
Gson gson = new Gson();

Set<String> hashSet = new HashSet<String>();
Set<String> treeSet = new TreeSet<String>();

//初始化数组
String[] keys = new String[20];
for (int i=0; i < 10 ; i++) {
keys[i] = i+"";
}
keys[10] = "99";
for (int i=11; i < 20 ; i++) {
keys[i] = (i-10)+"";
}

hashSet.addAll(Arrays.asList(keys));
treeSet.addAll(Arrays.asList(keys));

System.out.println(gson.toJson(keys));
//去重，无序
System.out.println(hashSet);
//去重，有序
System.out.println(treeSet);

//最后再转为数组
System.out.println(gson.toJson(treeSet.toArray()));

}

资料：http://simplehumn.iteye.com/blog/812064（详见评论部分）

set介绍：http://www.cnblogs.com/Terry-greener/archive/2011/12/02/2271707.html