案例：解决SimpleDateFormat格式化时间异常 java.lang.NumberFormatException: For input string: "20022E.20022E4

Posted 2023-02-06 袁义锐

多线程下，使用SimpleDateFormat格式化时间，会发生如下异常的情况

异常内容：

java.lang.NumberFormatException: For input string: "20022E.20022E44"
	at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2043) ~[?:1.8.0_181]
	at sun.misc.FloatingDecimal.parseDouble(FloatingDecimal.java:110) ~[?:1.8.0_181]
	at java.lang.Double.parseDouble(Double.java:538) ~[?:1.8.0_181]
	at java.text.DigitList.getDouble(DigitList.java:169) ~[?:1.8.0_181]
	at java.text.DecimalFormat.parse(DecimalFormat.java:2089) ~[?:1.8.0_181]
	at java.text.SimpleDateFormat.subParse(SimpleDateFormat.java:1869) ~[?:1.8.0_181]
	at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1514) ~[?:1.8.0_181]
	at java.text.DateFormat.parse(DateFormat.java:364) ~[?:1.8.0_181]

解决办法比较多，我这里仅举一个案例：ThreadLocal

static String pattern ="yyyy-MM-dd";
    private static ThreadLocal<SimpleDateFormat> yyyymmdd = new ThreadLocal<SimpleDateFormat>() 
        @Override
        protected SimpleDateFormat initialValue() 
            return new SimpleDateFormat(pattern);
        
    ;

    public static String format(Date date) 
        return yyyymmdd.get().format(date);
    

    public static Date parse(String dateStr) throws Exception 
        return yyyymmdd.get().parse(dateStr);