/**
 * Method will take Date in "MMMM, dd yyyy HH:mm:s" format and return time difference like added: 3 min ago
 *
 * @param date : date in "MMMM, dd yyyy HH:mm:s" format
 * @return : time difference
 */
private String getDurationTimeStamp(String date) {
    String timeDifference = "";

    //date formatter as per the coder need
    SimpleDateFormat sdf = new SimpleDateFormat("MMMM, dd yyyy HH:mm:s");
    TimeZone timeZone = TimeZone.getTimeZone("EST");
    sdf.setTimeZone(timeZone);
    Date startDate = null;
    try {
        startDate = sdf.parse(date);
    } catch (ParseException e) {
        MyLog.printStack(e);
    }

    //end date will be the current system time to calculate the lapse time difference
    Date endDate = new Date();

    //get the time difference in milliseconds
    long duration = endDate.getTime() - startDate.getTime();

    long diffInSeconds = TimeUnit.MILLISECONDS.toSeconds(duration);
    long diffInMinutes = TimeUnit.MILLISECONDS.toMinutes(duration);
    long diffInHours = TimeUnit.MILLISECONDS.toHours(duration);
    long diffInDays = TimeUnit.MILLISECONDS.toDays(duration);

    if (diffInDays >= 365) {
        int year = (int) (diffInDays / 365);
        timeDifference = year + mContext.getString(R.string.year_ago);
    } else if (diffInDays >= 30) {
        int month = (int) (diffInDays / 30);
        timeDifference = month + mContext.getString(R.string.month_ago);
    }
    //if days are not enough to create year then get the days
    else if (diffInDays >= 1) {
        timeDifference = diffInDays + mContext.getString(R.string.day_ago);
    }
    //if days value<1 then get the hours
    else if (diffInHours >= 1) {
        timeDifference = diffInHours + mContext.getString(R.string.hour_ago);
    }
    //if hours value<1 then get the minutes
    else if (diffInMinutes >= 1) {
        timeDifference = diffInMinutes + mContext.getString(R.string.min_ago);
    }
    //if minutes value<1 then get the seconds
    else if (diffInSeconds >= 1) {
        timeDifference = diffInSeconds + mContext.getString(R.string.sec_ago);
    } else if (timeDifference.isEmpty()) {
        timeDifference = mContext.getString(R.string.now);
    }

    return mContext.getString(R.string.added) + " " + timeDifference;
}

请参阅此处“日期及时间模式”。http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html

import java.text.SimpleDateFormat;
import java.util.Date;
import java.text.ParseException;

public class DateConversionExample{

  public static void main(String arg[]){

    try{

    SimpleDateFormat sourceDateFormat = new SimpleDateFormat("yyyy-MM-DD HH:mm:ss");

    Date date = sourceDateFormat.parse("2011-01-18 00:00:00.0");


    SimpleDateFormat targetDateFormat = new SimpleDateFormat("yyyy-MM-dd");
    System.out.println(targetDateFormat.format(date));

    }catch(ParseException e){
        e.printStackTrace();
    }
  } 

}

try
 {
    String date_s = "2011-01-18 00:00:00.0";
    SimpleDateFormat simpledateformat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S");
    Date tempDate=simpledateformat.parse(date_s);
    SimpleDateFormat outputDateFormat = new SimpleDateFormat("yyyy-MM-dd");           
    System.out.println("Output date is = "+outputDateFormat.format(tempDate));
  } catch (ParseException ex) 
  {
        System.out.println("Parse Exception");
  }

public class SystemDateTest {

    String stringDate;

    public static void main(String[] args) {
        SystemDateTest systemDateTest = new SystemDateTest();
        // format date into String
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd-MM-yyyy hh:mm:ss");
        systemDateTest.setStringDate(simpleDateFormat.format(systemDateTest.getDate()));
        System.out.println(systemDateTest.getStringDate());
    }

    public Date getDate() {
        return new Date();
    }

    public String getStringDate() {
        return stringDate;
    }

    public void setStringDate(String stringDate) {
        this.stringDate = stringDate;
    }
}

为什么不简单地使用它呢

Date convertToDate(String receivedDate) throws ParseException{
        SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy");
        Date date = formatter.parse(receivedDate);
        return date;
    }

还有，这是另一种方式:

DateFormat df = new SimpleDateFormat("dd/MM/yyyy");
String requiredDate = df.format(new Date()).toString();

or

Date requiredDate = df.format(new Date());

答案当然是创建一个SimpleDateFormat对象，并使用它来解析“字符串到日期”并将“日期到字符串”格式化。如果您已经尝试了SimpleDateFormat，它没有工作，那么请显示您的代码和您可能收到的任何错误。

附录:String格式中的“mm”与“mm”不一样。用MM表示月，用MM表示分钟。另外，yyyyy和yyyy也不一样。例如,:

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class FormateDate {

    public static void main(String[] args) throws ParseException {
        String date_s = "2011-01-18 00:00:00.0";

        // *** note that it's "yyyy-MM-dd hh:mm:ss" not "yyyy-mm-dd hh:mm:ss"  
        SimpleDateFormat dt = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
        Date date = dt.parse(date_s);

        // *** same for the format String below
        SimpleDateFormat dt1 = new SimpleDateFormat("yyyy-MM-dd");
        System.out.println(dt1.format(date));
    }

}