package anni.core.web.json;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;


/**
 * 樹的工具類.
 * 主要用于LongTreeNode與json之間的轉換
 *
 * @author Lingo
 * @since 2007-09-15
 */
public class LongTreeUtils {
    /** * logger. */
    private static Log logger = LogFactory.getLog(LongTreeUtils.class);

    /** * 工具類需要的保護構造方法. */
    protected LongTreeUtils() {
        logger.info("start");
    }

    /**
     * 不允許將自表外鍵關系設置成環狀.
     * 就是說，當前的current的子節點中，如果包含parent，就不能把parent設置為current的上級節點
     *
     * @param current TreeEntityBean
     * @param parent TreeEntityBean
     * @param <T> TreeEntityBean
     * @return boolean 是否形成環狀
     */
    public static <T extends LongTreeNode> boolean isDeadLock(
        LongTreeNode<T> current, LongTreeNode<T> parent) {
        if ((current == null) || (parent == null)
                || current.equals(parent)) {
            return true;
        } else {
            for (T child : current.getChildren()) {
                boolean isDeadLock = isDeadLock(child, parent);

                if (isDeadLock) {
                    return true;
                }
            }
        }

        return false;
    }
}