Java tutorial
//package com.java2s; /* * Copyright (C) 2016 venshine.cn@gmail.com * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.text.DateFormat; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Calendar; public class Main { public static final String DATE_FORMAT = "yyyyMMdd"; public static final String[] WEEKS = { "SUN", "MON", "TUES", "WED", "THUR", "FRI", "SAT" }; /** * Get week by datetime, datetime format must be contracted with DATE_FORMAT. * * @param datetime * @return */ public static String getWeek(String datetime) { Calendar cal = Calendar.getInstance(); DateFormat f = new SimpleDateFormat(DATE_FORMAT); try { cal.setTime(f.parse(datetime)); int week_index = cal.get(Calendar.DAY_OF_WEEK) - 1; if (week_index < 0) { week_index = 0; } return WEEKS[week_index]; } catch (ParseException e) { e.printStackTrace(); } return ""; } }