一行代码实现java list去重

1.不带类型写法：

1	List listWithoutDup = new ArrayList(new HashSet(listWithDup));

2.带类型写法（以String类型为例）：
1)Java 7以下写法：

1	List<string> listWithoutDup = new ArrayList<string>(new HashSet<string>(listWithDup));</string></string></string>

2)Java 7及以上写法：

1	List<string> listWithoutDup = new ArrayList<>(new HashSet<>(listWithDup));</string>

样例：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

import java.util.ArrayList; import java.util.HashSet; import java.util.List;   public class Test {     public static void main(String[] args) {         List<string> listWithDup = new ArrayList<string>();         listWithDup.add("1");         listWithDup.add("2");         listWithDup.add("3");         listWithDup.add("1");           List<string> listWithoutDup = new ArrayList<string>(new HashSet<string>(listWithDup));         System.out.println("list with dup:"+ listWithDup);         System.out.println("list without dup:"+ listWithoutDup);     } }</string></string></string></string></string>

样例运行结果： list with dup:[1, 2, 3, 1]
list without dup:[3, 2, 1]