我想将代码从Joda迁移到java. time。我使用DateTimeFormatter解析和格式化多个日期。问题在于DateTimeFormatter.format（...），返回的字符串是“2023-02- 08 T09：30：00.000+01：00+0100+01”，而不是2023-02- 08 T09：30：00.000+01：00
我写了一个测试来暴露我的问题。错误的测试是testFormatWithJava（）

import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeFormatterBuilder;
import java.time.temporal.TemporalAccessor;
import java.util.Date;

import org.joda.time.DateTime;
import org.joda.time.format.ISODateTimeFormat;
import org.junit.Before;
import org.junit.Test;

public class TestU {

    private DateTimeFormatter dateTimeFormatter;

    @Before
    public void before() {
        DateTimeFormatterBuilder dateTimeFormatterBuilder = new DateTimeFormatterBuilder()
                .append(DateTimeFormatter.ISO_LOCAL_DATE_TIME) //
                .optionalStart().appendPattern(".SSS").optionalEnd() //
                .optionalStart().appendOffset("+HH:MM", "+00:00").optionalEnd() //
                .optionalStart().appendOffset("+HHMM", "+0000").optionalEnd() //
                .optionalStart().appendOffset("+HH", "Z").optionalEnd();
        dateTimeFormatter = dateTimeFormatterBuilder.toFormatter();
    }

    @Test
    public void testParseDateStringWithJoda() {
        String dateString1 = "2023-02-08T09:30:00.787+0000";
        String dateString2 = "2023-02-08t09:30:00.000+01:00";
        String dateString3 = "2013-07-05t14:04:15+01:00";

        org.joda.time.format.DateTimeFormatter formatter = ISODateTimeFormat.dateTime().withOffsetParsed();
        org.joda.time.format.DateTimeFormatter formatterWithoutMs = ISODateTimeFormat.dateTimeNoMillis()
                .withOffsetParsed();

        DateTime dateTime1 = formatter.parseDateTime(dateString1);
        DateTime dateTime2 = formatter.parseDateTime(dateString2);
        DateTime dateTime3 = formatterWithoutMs.parseDateTime(dateString3);

        assertEquals("Wed Feb 08 10:30:00 CET 2023", dateTime1.toDate().toString());
        assertEquals("Wed Feb 08 09:30:00 CET 2023", dateTime2.toDate().toString());
        assertEquals("Fri Jul 05 15:04:15 CEST 2013", dateTime3.toDate().toString());
    }

    @Test
    public void testParseDateStringWithJava() {
        String dateString1 = "2023-02-08T09:30:00.787+0000";
        String dateString2 = "2023-02-08t09:30:00.000+01:00";
        String dateString3 = "2013-07-05t14:04:15+01:00";

        TemporalAccessor temporalAccessor1 = dateTimeFormatter.parse(dateString1);
        TemporalAccessor temporalAccessor2 = dateTimeFormatter.parse(dateString2);
        TemporalAccessor temporalAccessor3 = dateTimeFormatter.parse(dateString3);

        assertEquals("Wed Feb 08 10:30:00 CET 2023", Date.from(Instant.from(temporalAccessor1)).toString());
        assertEquals("Wed Feb 08 09:30:00 CET 2023", Date.from(Instant.from(temporalAccessor2)).toString());
        assertEquals("Fri Jul 05 15:04:15 CEST 2013", Date.from(Instant.from(temporalAccessor3)).toString());
    }

    @Test
    public void testFormatWithJoda() {
        Date date = Date.from(LocalDateTime.of(2023, 02, 8, 9, 30).atZone(ZoneId.of("Europe/Paris")).toInstant());

        org.joda.time.format.DateTimeFormatter formatter = ISODateTimeFormat.dateTime().withOffsetParsed();
        DateTime dt = new DateTime(date);

        assertEquals("2023-02-08T09:30:00.000+01:00", formatter.print(dt));
    }

    @Test
    public void testFormatWithJava() {
        Date date = Date.from(LocalDateTime.of(2023, 02, 8, 9, 30).atZone(ZoneId.of("Europe/Paris")).toInstant());

        assertEquals("2023-02-08T09:30:00.000+01:00",
                dateTimeFormatter.withZone(ZoneId.systemDefault()).format(date.toInstant()));
    }
}