使用LocalDateTime解析带有微秒，纳秒时间格式yyyy-MM-dd'T'HH:mm:ss.SSSSSSZ

1.使用SimpleDateFormat解析带有微秒，纳秒格式的时间会出现多几分钟的现象，因为SimpleDateFormat只能解析到毫秒，会将微秒等当做毫秒来解析
2.使用LocalDateTime来正确解析，JDK1.8后加入

package javaTEST;

import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Calendar;
import java.util.Date;

public class Test2 
{
	public static void main(String[] args) throws Exception
	{
		String valueIn = "2019-02-19T23:28:04.434410+0800";
		String formatIn = "yyyy-MM-dd'T'HH:mm:ss.SSSSSSZ";
		String formatOut = "yyyy-MM-dd HH:mm:ss";
		String formatOut2 = "yyyy-MM-dd'T'HH:mm:ss.SSSSSSZ";
		
		//使用SimpleDateFormat解析
		Date date= new SimpleDateFormat(formatIn).parse(valueIn);
		String out1= new SimpleDateFormat(formatOut).format(date);
		System.out.println("SimpleDateFormat out:" + out1 +",会多几分钟");
		
		//使用LocalDateTime
		//先获取时间纳秒
		LocalDateTime ldt = LocalDateTime.parse(valueIn, DateTimeFormatter.ofPattern(formatIn));
		ZonedDateTime zdt = ZonedDateTime.of(ldt, ZoneId.systemDefault());        
		String out2 = DateTimeFormatter.ofPattern(formatOut).format(zdt);
		System.out.println("LocalDateTime out:" + out2);
		
		//double类型时间2019-02-19T23:28:04.434410+0800=1550590084.434410还原yyyy-MM-dd'T'HH:mm:ss.SSSSSSZ
		double d_time =  1550590084.434410;
		BigDecimal bd = new BigDecimal(d_time).setScale(6,BigDecimal.ROUND_DOWN);
		long Millitime = (long)(d_time*1000);
		int Nano = Integer.parseInt(bd.toString().substring(bd.toString().indexOf(".")+1)+"000");
		
		Date date1= new Date(Millitime);
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date1);
		int YEAR = calendar.get(Calendar.YEAR);
		int MONTH = calendar.get(Calendar.MONTH)+1;
		int DAY_OF_MONTH = calendar.get(Calendar.DAY_OF_MONTH);
		int HOUR_OF_DAY = calendar.get(Calendar.HOUR_OF_DAY);
		int MINUTE = calendar.get(Calendar.MINUTE);
		int SECOND = calendar.get(Calendar.SECOND);
		
		LocalDateTime ldt2 = LocalDateTime.of(YEAR, MONTH, DAY_OF_MONTH, HOUR_OF_DAY, MINUTE, SECOND, Nano);
		//必须要指定时区，要不然会报java.time.temporal.UnsupportedTemporalTypeException: Unsupported field: OffsetSeconds
		ZonedDateTime zdt2 = ZonedDateTime.of(ldt2, ZoneId.systemDefault()); 
		String out3 = DateTimeFormatter.ofPattern(formatOut2).format(zdt2);
		System.out.println("LocalDateTime 1550590084.434410 out:" + out3);
	}
}

结果:

SimpleDateFormat out:2019-02-19 23:35:18,会多几分钟
LocalDateTime out:2019-02-19 23:28:04
LocalDateTime 1550590084.434410 out:2019-02-19T23:28:04.434410+0800