import com.dianping.lion.shade.org.apache.curator.shaded.com.google.common.collect.Lists;
import io.swagger.models.auth.In;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;

public class Test02 {
    public static void main(String[] args) {

        ArrayList<Integer> integers = new ArrayList<>();
        integers.add(1);
        integers.add(2);
        integers.add(3);
        integers.add(4);
        List<List<Integer>> orderNoListList = Lists.partition(integers, 2);

        System.out.printf(orderNoListList.toString());

        List<Integer> listNew= Lists.reverse(integers);

        System.out.printf(listNew.toString());

        System.out.println("---");
        ArrayList<Integer> integers1 = new ArrayList<>();
        integers1.add(1);
        integers1.add(2);
        integers1.add(3);
        int arrayListCapacity = getArrayListCapacity(integers1);
        System.out.println(arrayListCapacity+"");
        ArrayList<Object> objects = Lists.newArrayListWithCapacity(2);
        int arrayListCapacity1 = getArrayListCapacity(objects);
        System.out.println(arrayListCapacity1+"");
    }

    public static int getArrayListCapacity(ArrayList<?> arrayList) {
        Class<ArrayList> arrayListClass = ArrayList.class;
        try {
            Field field = arrayListClass.getDeclaredField("elementData");
            field.setAccessible(true);
            Object[] objects = (Object[])field.get(arrayList);
            return objects.length;
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
            return -1;
        } catch (IllegalAccessException e) {
            e.printStackTrace();
            return -1;
        }
    }

}
import com.dianping.lion.shade.org.apache.curator.shaded.com.google.common.collect.ImmutableList;
import com.dianping.lion.shade.org.apache.curator.shaded.com.google.common.collect.Lists;

public class Test03 {
    public static void main(String[] args) {
        String str="3r34dsfsd";
        ImmutableList<Character> characters = Lists.charactersOf(str);
        System.out.println(characters);
    }
}

 

posted on 2020-09-22 20:53  王洪洪  阅读(484)  评论(0编辑  收藏  举报