时间格式化工具类，非常好用

public class TimeUtil {

private static String DATE_FORMAT = "yyyy-MM-dd HH:mm:ss";

public static String timeLogic(String dateStr) {
Calendar calendar = Calendar.getInstance();
calendar.get(Calendar.DAY_OF_MONTH);
long now = calendar.getTimeInMillis();
Date date = strToDate(dateStr);
calendar.setTime(date);
long past = calendar.getTimeInMillis();

// 相差的秒数
long time = (now - past) / 1000;

StringBuffer sb = new StringBuffer();
if (time > 0 && time < 60) { // 1小时内
return sb.append(time + "秒前").toString();
} else if (time > 60 && time < 3600) {
return sb.append(time / 60+"分钟前").toString();
} else if (time >= 3600 && time < 3600 * 24) {
return sb.append(time / 3600 +"小时前").toString();
}else if (time >= 3600 * 24 && time < 3600 * 48) {
return sb.append("昨天").toString();
}else if (time >= 3600 * 48 && time < 3600 * 72) {
return sb.append("前天").toString();
}else if (time >= 3600 * 72) {
return (int)(time/3600/24)+"天前";
}
return "";
}

/**
* 日期字符串转换为Date
* @param dateStr
* @return
*/
public static Date strToDate(String dateStr) {
Date date = null;

if (!TextUtils.isEmpty(dateStr)) {
DateFormat df = new SimpleDateFormat(DATE_FORMAT);
try {
date = df.parse(dateStr);
} catch (ParseException e) {
e.printStackTrace();
}
}
return date;
}

/**
* 将10位或者13位时间戳转换为日期格式：2016-07-18
* @param times
* @return
*/
public static String dateFormat(String times){
SimpleDateFormat sdf = new SimpleDateFormat("MM-dd");
if(times.length() == 13){
return sdf.format(new Date(Long.parseLong(times)));
}else if(times.length() == 10){
return sdf.format(new Date(Long.parseLong(times)*1000L));
}
return  null;
}
public static String dateFormat7(String times){
SimpleDateFormat sdf = new SimpleDateFormat("yy-MM-dd");
if(times.length() == 13){
return sdf.format(new Date(Long.parseLong(times)));
}else if(times.length() == 10){
return sdf.format(new Date(Long.parseLong(times)*1000L));
}
return  null;
}

/**
* 将10位或者13位时间戳转换为日期格式：2016年07月18日
* @param times
* @return
*/
public static String dateFormat2(String times){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日");
if(times.length() == 13){
return sdf.format(new Date(Long.parseLong(times)));
}else if(times.length() == 10){
return sdf.format(new Date(Long.parseLong(times)*1000L));
}
return  null;
}

/**
* 将10位或者13位时间戳转换为日期格式：2016-07-18 12:44
* @param times
* @return
*/
public static String dateFormat3(String times){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm");
if(times.length() == 13){
return sdf.format(new Date(Long.parseLong(times)));
}else if(times.length() == 10){
return sdf.format(new Date(Long.parseLong(times)*1000L));
}
return  null;
}
public static String dateFormat6(String times){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
if(times.length() == 13){
return sdf.format(new Date(Long.parseLong(times)));
}else if(times.length() == 10){
return sdf.format(new Date(Long.parseLong(times)*1000L));
}
return  null;
}

/**
* 将yyyy-MM-dd HH:mm转换为时间戳
* @param times
* @return
*/
public static Long dateFormat4(String times){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
try {
Date date = sdf.parse(times);
return  date.getTime();
} catch (ParseException e) {
e.printStackTrace();
}
return  null;
}

/**
* 计算两个日期之间相差的天数
* @param currentTime yyyy-MM-dd HH:mm
* @param publishTime yyyy-MM-dd HH:mm
* @return 返回整型的天数
*/
public static int betweenDays(String currentTime,String publishTime){
double dayss = -(dateFormat4(currentTime) - dateFormat4(publishTime)) / (1000*3600*24);
String[] ss = (dayss+"").split("\\.");
int days = Integer.valueOf(ss[0]);
return days;
}

/**
* 计算两个日期之间相差的小时
* @param currentTime yyyy-MM-dd HH:mm
* @param publishTime yyyy-MM-dd HH:mm
* @return
*/
public static int betweenHours(String currentTime,String publishTime){
double dayss = -(dateFormat4(currentTime) - dateFormat4(publishTime)) / (1000*3600);
String[] ss = (dayss+"").split("\\.");
int hours = Integer.valueOf(ss[0]);
return hours;
}

/**
* 将10位或者13位时间戳转换为日期格式：2016-07-18 12:44:22
* @param times
* @return
*/
public static String dateFormat5(String times){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
if(times.length() == 13){
return sdf.format(new Date(Long.parseLong(times)));
}else if(times.length() == 10){
return sdf.format(new Date(Long.parseLong(times)*1000L));
}
return  null;
}
}