List,Set,Map和数组之间的相互转换

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list,set,map,数组间的相互转换1.list转setSet set = new HashSet(new ArrayList()); 2.set转listList list = new ArrayList(new HashSet());3.数组转为listList stooges = Arrays.asList("Larry", "Moe", "Curly");或者String[] arr = {"1", "2"};List list = Arrays.asList(arr);4.数组转为setint[] a = { 1, 2, 3 };Set set = new HashSet(Arrays.asList(a));5.map的相关操作。Map map = new HashMap();map.put("1", "a");map.put('2', 'b');map.put('3', 'c');System.out.println(map);// 输出所有的值System.out.println(map.keySet());// 输出所有的键System.out.println(map.values());// 将map的值转化为ListList list = new ArrayList(map.values());System.out.println(list);// 将map的值转化为SetSet set = new HashSet(map.values());System.out.println(set);6.list转数组List list = Arrays.asList("a","b");String[] arr = (String[])list.toArray(new String[list.size()]);System.out.println(Arrays.toString(arr));

原文地址：http://blog.csdn.net/a597926661/article/details/8649884