DateTimeFormatterWrapper.java

package x;

import java.text.FieldPosition;
import java.text.Format;
import java.text.ParsePosition;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.temporal.TemporalAccessor;
import java.util.Objects;

public class DateTimeFormatterWrapper extends Format {

	private DateTimeFormatter _wrappedFormatter;

	public DateTimeFormatterWrapper( DateTimeFormatter wrappedFormatter ) {
		Objects.requireNonNull( wrappedFormatter );
		_wrappedFormatter = wrappedFormatter;
	}

	@Override
	public StringBuffer format( Object object, StringBuffer toAppendTo, FieldPosition pos ) {
		toAppendTo.append( _wrappedFormatter.format( (TemporalAccessor)object ) );
		return toAppendTo;
	}

	@Override
	public Object parseObject( String source, ParsePosition pos ) {
		pos.setIndex( source.length() );
		return _wrappedFormatter.parse( source );
	}
	
	public static void main( String[] args ) {
		DateTimeFormatterWrapper f = new DateTimeFormatterWrapper( DateTimeFormatter.ofPattern( "dd.MM.YYYY" ) );
		System.out.println( f.format( LocalDate.of( 1979, 11, 9 ) ) );
	}
}