日期公用类 - 黑马程序员技术交流社区

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.lang.StringUtils;
public class DateUtils {
private static final Map<String, String> dtfmt = new HashMap<String, String>();
private static final Map<String, DateFormat> fmt = new HashMap<String, DateFormat>();
static {
dtfmt.put("\\d{8}", "yyyyMMdd");
dtfmt.put("\\d{12}", "yyyyMMddHHmm");
dtfmt.put("\\d{14}", "yyyyMMddHHmmss");
dtfmt.put("\\d{4}-\\d{2}-\\d{2}", "yyyy-MM-dd");
dtfmt.put("\\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}", "yyyy-MM-dd HH:mm");
dtfmt.put("\\d{4}-\\d{2}-\\d{2} \\d{2}\\d{2}", "yyyy-MM-dd HHmm");
dtfmt.put("\\d{2}:\\d{2}:\\d{2}", "HH:mm:ss");
dtfmt.put("\\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}:\\d{2}", "yyyy-MM-dd HH:mm:ss");
dtfmt.put("\\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}:\\d{2}\\..*", "yyyy-MM-dd HH:mm:ss.SSS");
dtfmt.put("\\d{4}/\\d{2}/\\d{2}", "yyyy/MM/dd");
dtfmt.put("\\d{4}年\\d{2}月\\d{2}日", "yyyy年MM月dd日");
dtfmt.put("\\d{4}年\\d{2}月\\d{2}日 \\d{2}时\\d{2}分\\d{2}秒", "yyyy年MM月dd日 HH时mm分ss秒");
fmt.put("yyyyMMdd", new SimpleDateFormat("yyyyMMdd"));
fmt.put("yyyyMMddHHmm", new SimpleDateFormat("yyyyMMddHHmm"));
fmt.put("yyyyMMddHHmmss", new SimpleDateFormat("yyyyMMddHHmmss"));
fmt.put("yyyy-MM-dd", new SimpleDateFormat("yyyy-MM-dd"));
fmt.put("yyyy-MM-dd HH:mm", new SimpleDateFormat("yyyy-MM-dd HH:mm"));
fmt.put("yyyy-MM-dd HHmm", new SimpleDateFormat("yyyy-MM-dd HHmm"));
fmt.put("yyyy-MM-dd HH:mm:ss", new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
fmt.put("HH:mm:ss", new SimpleDateFormat("HH:mm:ss"));
fmt.put("yyyy-MM-dd HH:mm:ss.SSS", new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS"));
fmt.put("yyyy年MM月dd日", new SimpleDateFormat("yyyy年MM月dd日"));
fmt.put("yyyy年MM月dd日 HH时mm分ss秒", new SimpleDateFormat("yyyy年MM月dd日 HH时mm分ss秒"));
fmt.put("yyyy/MM/dd", new SimpleDateFormat("yyyy/MM/dd"));
}
public static String getCurrentDate(String yyyyMMdd) {
SimpleDateFormat formatDate = new SimpleDateFormat(yyyyMMdd);
Calendar cal = Calendar.getInstance();
return formatDate.format(cal.getTime());
}
public static String getCurrentYear() {
SimpleDateFormat formatDate = new SimpleDateFormat("yyyy-MM-dd");
Calendar cal = Calendar.getInstance();
String str = formatDate.format(cal.getTime());
String[] strArr = str.split("-");
return strArr[0];
}
public static String getParseDate(Date date) {
String str = "";
if (date != null) {
SimpleDateFormat formatDate = new SimpleDateFormat("yyyy-MM-dd");
str = formatDate.format(date);
}
return str;
}
public static Date parseDate(String date) {
Date dat = null;
if (date != null && date.trim().length() > 0) {
SimpleDateFormat formatDate = new SimpleDateFormat("yyyy-MM-dd");
try {
dat = formatDate.parse(date);
} catch (ParseException e) {
dat = null;
}
} else
dat = new Date();
return dat;
}
/**
*
* @param year
* int 年份
* @param month
* int 月份
*
* @return int 某年某月的第一天
*/
@SuppressWarnings("unused")
public static int getFirstDayOfMonth(int year, int month) {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, year);
cal.set(Calendar.MONTH, month);
return cal.getActualMinimum(Calendar.DATE);
}
/**
*
* @param year
* int 年份
* @param month
* int 月份
*
* @return int 某年某月的最后一天
*/
@SuppressWarnings("unused")
public static int getLastDayOfMonth(int year, int month) {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, year);
cal.set(Calendar.MONTH, month);
return cal.getActualMaximum(Calendar.DATE);
}
/**
* 转换秒为 x天x小时x分x秒
*
* @param seconds
* @return
*/
public static String getDayHourMinSec(long seconds) {
long day = seconds / (24 * 60 * 60);
long hour = (seconds - day * 24 * 60 * 60) / (60 * 60);
long min = (seconds - day * 24 * 60 * 60 - hour * 60 * 60) / 60;
long sec = seconds - day * 24 * 60 * 60 - hour * 60 * 60 - min * 60;
StringBuffer result = new StringBuffer();
if (day > 0) {
result.append(day + "天");
}
if (hour > 0) {
result.append(hour + "小时");
}
if (min > 0) {
result.append(min + "分");
}
if (sec > 0) {
result.append(sec + "秒");
}
if (result.length() == 0) {
result.append("0秒");
}
return result.toString();
}
/**
* 格式化日期为指定格式字符串
*
* @param date
* @param pattern
* @return
*/
public static String format(final java.util.Date date, final String pattern) {
if (StringUtils.isBlank(pattern) || !fmt.containsKey(pattern)) {
throw new IllegalArgumentException("不支持格式化Pattern");
}
return fmt.get(pattern).format(date);
}
/**
*
* @param date
* @param time
* @return
*/
public static String getNormalDateTime(String date, String time) {
return StringUtils.leftPad(date.replaceAll("-|/|年|月|日", ""), 8, "20") + StringUtils.rightPad(StringUtils.leftPad(time.replaceAll(":|时|分|秒", ""), 4, "0"), 6, "0");
}
/**
* 根据日期字符串生成java.util.Date
* @param dateStr
* @return
*/
public static java.util.Date toDate(String dateStr) {
if (StringUtils.isBlank(dateStr)) {
return null;
}
String pattern = getDatePattern(dateStr);
if (StringUtils.isBlank(pattern)) {
throw new IllegalArgumentException("无法识别日期字符串格式[" + dateStr + "]");
}
return toDate(dateStr, pattern);
}
/**
* 根据日期字符串及格式生成java.util.Date
*
* @param dateStr
* @param pattern
* @return
*/
public static java.util.Date toDate(String dateStr, String pattern) {
if (StringUtils.isBlank(dateStr)) {
return null;
}
try {
return org.apache.commons.lang.time.DateUtils.parseDate(dateStr, new String[] { pattern });
} catch (ParseException e) {
throw new IllegalArgumentException(String.format("转换日期字符串不正确,字符串:%s,格式:%s", dateStr, pattern));
}
}
/**
* 根据日期字符串取得日期格式
*
* @param dateStr
* @return
*/
public static String getDatePattern(String dateStr) {
if (StringUtils.isBlank(dateStr)) {
return null;
}
String pattern = null;
for (String key : dtfmt.keySet()) {
if (dateStr.matches(key)) {
return dtfmt.get(key);
}
}
return pattern;
}
}

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