SimpleDateFormatter does not recognize months

I want to parse a date string but I fail miserably. To illustrate my problem I wrote this simple JUnit test:

@Test
public void testParseJavaDate() throws ParseException {     
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-DD_HH-mm-ss", Locale.GERMAN);

    String inputtime = "2011-04-21_16-01-08";
    Date parse = sdf.parse(inputtime);

    assertEquals(inputtime,sdf.format(parse));
}

This test fails with this message:

org.junit.Com开发者_运维问答parisonFailure: expected:<2011-0[4]-21_16-01-08> but was:<2011-0[1]-21_16-01-08>

I don't get why the formatter cannot parse the date correctly. Do you have any ideas?

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss", Locale.GERMAN);

String inputtime = "2011-04-21_16-01-08";
Date parse = sdf.parse(inputtime);

use dd instead of DD.

You want "dd" (day in month), not "DD" (day in year):

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss", Locale.GERMAN);

Use d instead of D, as D is the 'Day in year', so the month is forced to match the 21st day of the year (which is in January).

all the previous is right but u must also use 'mm' in place of 'MM' and vise versa because 'M' Display minute with a leading zero as necessary

so ur code will be as follows

public void testParseJavaDate() throws ParseException {
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-mm-dd_HH-MM-ss", Locale.GERMAN);

    String inputtime = "2011-04-21_16-01-08";
    Date parse = sdf.parse(inputtime);

    sdf = new SimpleDateFormat("dd/mm/yyyy HH:MM:ss", Locale.GERMAN);

    System.out.println(sdf.format(parse));

    assertEquals(inputtime, sdf.format(parse));
}

and it will print

run: 21/04/2011 16:01:08 BUILD SUCCESSFUL (total time: 0 seconds)