取到root字段后不会转换成Map.Entry类型了
import java.lang.reflect.Field;
import java.util.TreeMap;
public class Main {
public static final Object PRESENT = new Object();
public static void main(String[] args) throws Exception {
TreeMap<Integer, Object> tree = new TreeMap<Integer, Object>();
tree.put(1, PRESENT);
Class<? extends TreeMap> c = tree.getClass();
Field root = c.getDeclaredField("root");
root.setAccessible(true);
System.out.println(root.getType());
}
}