java去除重复字符串

package  www.wlkankan.cn
public class Test {
    private static final Object object = new Object();
    public static void main(String[] args) {
        //利用map的key不能重复
        Map<Object, Object> map = Maps.newLinkedHashMap();
        //将字符串进行肢解
        char[] str = "abcdefgabcdefgoop".toCharArray();
        //将直接后的内容用作map的key
        for (int i = 0; i < str.length; i++)
            map.put(str[i], object);
        //最终的字符串
        StringBuilder builder = new StringBuilder();
        //便利最后获得到的map,重新组装到字符串
        for (Map.Entry<Object, Object> entry : map.entrySet())
        builder.append(entry.getKey());
        System.out.println(builder.toString());
    }
}