Java日期时间API系列35-----Jdk8中java.time包中的新的日期时间API类应用，微秒和纳秒等更精确的时间格式化和解析。

/**
     * 解析Timestamp格式字符串为LocalDateTime  默认格式 yyyy-mm-dd hh:mm:ss.fffffffff 其中 fffffffff 纳秒，省略后面的0 比如：
     * <pre>
     * 2020-05-23 17:06:30.0
     * 2020-05-23 17:06:30.272
     * 2020-05-23 17:06:30.27215
     * 2020-05-23 17:06:30.27215062
     *</pre>
     * @param text
     * @return LocalDateTime
     */
    public static LocalDateTime parseTimestampStyleToLocalDateTime(String text){
        //预处理
        Objects.requireNonNull(text, "text");
        text=text.trim();
        if(!text.contains(".")){
            throw new DateTimeException("text is not supported! " + text);
        }
        
        //.分割成2部分，分别分析
        String[] textArr = text.split("\\.");
        String main = textArr[0];
        String nanoOfSecond = textArr[1];
        int mainLen = main.length();
        int len = nanoOfSecond.length();
        if(mainLen != DateFormatPattern.YYYY_MM_DD_HH_MM_SS.length()){
            throw new DateTimeException("text is not supported! " + text);
        }
        if(len>9){
            throw new DateTimeException("text is not supported! " + text);
        }
        
        //纳秒部分补0
        StringBuilder sb = new StringBuilder();
        for(int i=0;i<9-len;i++){
            sb.append("0");
        }
        nanoOfSecond = nanoOfSecond+sb.toString();
        text = main+"."+nanoOfSecond;
        
        //使用yyyy-MM-dd HH:mm:ss.SSSSSSSSS 标准格式解析
        return parseToLocalDateTime(text, DateTimeFormatterUtil.YYYY_MM_DD_HH_MM_SS_SSSSSSSSS_FMT);
    }

  /**
     * 含纳秒Timestamp时间格式解析
     */
    @Test
    public void parseTimestampStyleTest(){
        
        Date date = DateTimeFormatterUtil.smartParseToDate("2020-05-23 17:06:30");
        
        Date date2 = DateTimeFormatterUtil.parseTimestampStyleToDate("2020-05-23 17:06:30.0");
        
        Date date3 = DateTimeFormatterUtil.parseTimestampStyleToDate("2020-05-23 17:06:30.0");
        
        Assert.assertEquals(date, date2);
        Assert.assertEquals(date2, date3);
        
        LocalDateTime localDateTime1 = DateTimeFormatterUtil.smartParseToLocalDateTime("2020-05-23 17:06:30.272150");
        
        LocalDateTime localDateTime2 = DateTimeFormatterUtil.smartParseToLocalDateTime("2020-05-23 17:06:30.27215");
        Assert.assertEquals(localDateTime1, localDateTime2);
    }

 // ==================================yyyy-MM-dd HH:mm:ss.SSSSSS 相关Pattern==================================    
    
    /**
     * yyyy-MM-dd HH:mm:ss.SSSSSS 比如：2020-05-23 17:06:30.272150
     */
    public static final String YYYY_MM_DD_HH_MM_SS_SSSSSS = "yyyy-MM-dd HH:mm:ss.SSSSSS";
    
    
    
    // ==================================yyyy-MM-dd HH:mm:ss.SSSSSSSSS 相关Pattern==================================    
    
    /**
     * yyyy-MM-dd HH:mm:ss.SSSSSSSSS 比如：2020-05-23 17:06:30.272150620
     */
    public static final String YYYY_MM_DD_HH_MM_SS_SSSSSSSSS = "yyyy-MM-dd HH:mm:ss.SSSSSSSSS";    

  /**
     * 含纳秒时间格式化
     */
    @Test
    public void formatTimeWithNanoTest(){
        LocalDateTime localDateTime = DateTimeFormatterUtil.smartParseToLocalDateTime("2020-05-23T17:06:30.272150620+08:00");
        //时间格式化
        Assert.assertEquals("17:06:30.272", DateTimeFormatterUtil.format(localDateTime, DateTimeFormatterUtil.HH_MM_SS_SSS_FMT));
        Assert.assertEquals("17:06:30.272150", DateTimeFormatterUtil.format(localDateTime, DateTimeFormatterUtil.HH_MM_SS_SSSSSS_FMT));
        Assert.assertEquals("17:06:30.272150620", DateTimeFormatterUtil.format(localDateTime, DateTimeFormatterUtil.HH_MM_SS_SSSSSSSSS_FMT));
        
        //日期时间格式化
        Assert.assertEquals("2020-05-23 17:06:30.272150", DateTimeFormatterUtil.format(localDateTime, DateTimeFormatterUtil.YYYY_MM_DD_HH_MM_SS_SSSSSS_FMT));
        Assert.assertEquals("2020-05-23 17:06:30.272150620", DateTimeFormatterUtil.format(localDateTime, DateTimeFormatterUtil.YYYY_MM_DD_HH_MM_SS_SSSSSSSSS_FMT));

        //ISO日期时间格式化
        Assert.assertEquals("2020-05-23T17:06:30.272150620+0800", DateTimeFormatterUtil.format(localDateTime, DateTimeFormatterUtil.YYYY_MM_DD_T_HH_MM_SS_SSSSSSSSS_Z_FMT));
        Assert.assertEquals("2020-05-23T17:06:30.272150620+08:00", DateTimeFormatterUtil.format(localDateTime, DateTimeFormatterUtil.YYYY_MM_DD_T_HH_MM_SS_SSSSSSSSS_XXX_Z_FMT));
    }

 /**
     * 含纳秒时间格式解析
     */
    @Test
    public void parseTimeWithNanoTest(){
        LocalDateTime localDateTime1 = DateTimeFormatterUtil.smartParseToLocalDateTime("2020-05-23T17:06:30.272150620+08:00");
        
        LocalDateTime localDateTime2 = DateTimeFormatterUtil.smartParseToLocalDateTime("2020-05-23T17:06:30.272150+08:00");
        
        LocalDateTime localDateTime3 = DateTimeFormatterUtil.smartParseToLocalDateTime("2020-05-23T17:06:30.272+08:00");
        
        Assert.assertTrue(localDateTime3.isBefore(localDateTime2));
        
        Assert.assertTrue(localDateTime2.isBefore(localDateTime1));
    }