LocalDate parse exception - java-8

Question

java.time.format.DateTimeParseException: Text '06/2018' could not be parsed: Unable to obtain LocalDate from TemporalAccessor: {Year=2018, MonthOfYear=6},ISO of type java.time.format.Parsed
after formatting Date to string and finally want to convert it to LocalDate field getting above exception.
String date1 = "14-Jun-18";
DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("d-MMM-yy");
LocalDate localDate1 = LocalDate.parse(date1,dateTimeFormatter);
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("MM/yyyy");
String s= localDate1.format(formatter);
LocalDate localDate4 = LocalDate.parse(s,formatter);

Answer 1

The JavaDoc on LocalDate says:
LocalDate is an immutable date-time object that represents a date, often viewed as year-month-day.
You'll need to either provide with a day, or build a DateTimeFormatter using DateTimeFormatterBuilder that defaults to a day:
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeFormatterBuilder;
import java.time.temporal.ChronoField;
import java.time.format.SignStyle;
public class TestDate {
public static void main(String args[]) {
String date1 = "14-Jun-18";
DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("d-MMM-yy");
LocalDate localDate1 = LocalDate.parse(date1,dateTimeFormatter);
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("MM/yyyy");
String s = localDate1.format(formatter);
System.out.println(s);
DateTimeFormatter formatterWithDefaultDay = new DateTimeFormatterBuilder()
.appendValue(ChronoField.MONTH_OF_YEAR, 2, 2, SignStyle.NEVER)
.appendPattern("/")
.appendValue(ChronoField.YEAR, 4, 4, SignStyle.NEVER)
.parseDefaulting(ChronoField.DAY_OF_MONTH, 1)
.toFormatter();
LocalDate localDateBasedOns = LocalDate.parse(s, formatterWithDefaultDay);
System.out.println(localDateBasedOns);
}
}
This prints:
06/2018
2018-06-01