DeleteAllContacts/app/src/main/java/me/utils/Utils.java

package me.yoqi.deleteallcontacts.utils;

import java.util.List;
import java.util.regex.Pattern;

public class Utils {

	/** 判断list 是否为空
	 * @param contactIds
	 * @return
	 */
	public static boolean isEmpty(List<String> contactIds) {
		return contactIds.size() > 0;
	}

	/** 判断 string是否为数字
	 * @param contactId
	 * @return
	 */
	public static boolean isNumber(String contactId) {
		Pattern pattern = Pattern.compile("^[-\\+]?[\\d]*$");
		return pattern.matcher(contactId).matches();
	}

	/** 判断string是否为空
	 * @param id
	 * @return
	 */
	public static boolean isEmpty(String id) {
		return id.length() > 0;
	}

}