这是我的方法，可以定义和输入输出格式。

public static String formattedDateFromString(String inputFormat, String outputFormat, String inputDate){
    if(inputFormat.equals("")){ // if inputFormat = "", set a default input format.
        inputFormat = "yyyy-MM-dd hh:mm:ss";
    }
    if(outputFormat.equals("")){
        outputFormat = "EEEE d 'de' MMMM 'del' yyyy"; // if inputFormat = "", set a default output format.
    }
    Date parsed = null;
    String outputDate = "";

    SimpleDateFormat df_input = new SimpleDateFormat(inputFormat, java.util.Locale.getDefault());
    SimpleDateFormat df_output = new SimpleDateFormat(outputFormat, java.util.Locale.getDefault());

    // You can set a different Locale, This example set a locale of Country Mexico.
    //SimpleDateFormat df_input = new SimpleDateFormat(inputFormat, new Locale("es", "MX"));
    //SimpleDateFormat df_output = new SimpleDateFormat(outputFormat, new Locale("es", "MX"));

    try {
        parsed = df_input.parse(inputDate);
        outputDate = df_output.format(parsed);
    } catch (Exception e) { 
        Log.e("formattedDateFromString", "Exception in formateDateFromstring(): " + e.getMessage());
    }
    return outputDate;

}

使用这两个作为类变量:

 public java.text.DateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
 private Calendar mDate = null;

像这样使用它:

 mDate = Calendar.getInstance();
 mDate.set(year,months,day);                   
 dateFormat.format(mDate.getTime());

日期和时间格式说明

EEE : Day ( Mon )
MMMM : Full month name ( December ) // MMMM February   
MMM : Month in words ( Dec )
MM : Month ( 12 )
dd : Day in 2 chars ( 03 )
d: Day in 1 char (3)
HH : Hours ( 12 )
mm : Minutes ( 50 )
ss : Seconds ( 34 )
yyyy: Year ( 2020 ) //both yyyy and YYYY are same
YYYY: Year ( 2020 )
zzz : GMT+05:30
a : ( AM / PM )
aa : ( AM / PM )
aaa : ( AM / PM )
aaaa : ( AM / PM )

最短的方法:

// 2019-03-29 16:11
String.format("%1$tY-%<tm-%<td %<tR", Calendar.getInstance())

%tR是%tH:%tM的缩写，<表示重用最后一个参数(1$)。

它等价于String。格式(“% 1 $ tY - % 1 $ tm - td % 1 $ % 1 $ tH: % 1 $ tm”,Calendar.getInstance ())

https://developer.android.com/reference/java/util/Formatter.html

这段代码将返回当前日期和时间:

public String getCurrDate()
{
    String dt;
    Date cal = Calendar.getInstance().getTime();
    dt = cal.toLocaleString();
    return dt;
}

android Time类提供了3种格式化方法http://developer.android.com/reference/android/text/format/Time.html

我是这样做的:

/**
* This method will format the data from the android Time class (eg. myTime.setToNow())   into the format
* Date: dd.mm.yy Time: hh.mm.ss
*/
private String formatTime(String time)
{
    String fullTime= "";
    String[] sa = new String[2];

    if(time.length()>1)
    {
        Time t = new Time(Time.getCurrentTimezone());
        t.parse(time);
        // or t.setToNow();
        String formattedTime = t.format("%d.%m.%Y %H.%M.%S");
        int x = 0;

        for(String s : formattedTime.split("\\s",2))
        {   
            System.out.println("Value = " + s);
            sa[x] = s;
            x++;
        }
        fullTime = "Date: " + sa[0] + " Time: " + sa[1];
    }
    else{
        fullTime = "No time data";
    }
    return fullTime;
}

我希望这对你有帮助:-)