SpringMVC日期格式属性自动转成时间戳实现源码分析

可以看到在castToLong方法里，对假想的数据类型做各种假设处理，很不幸的是我们试验的数据格式，是在NumberFormatException异常里完成的最后挣扎，使用JSONScanner类接收的请求数据。

可以看到在这里通过调用dateParser.scanISO8601DateIfMatch对数据进行解析，得到calendar对象实例，最终通过calendar获取时间戳，scanISO8601DateIfMatch方法逻辑很复杂，总共有450多行，这里截取了其中一部分展现一下：

private boolean scanISO8601DateIfMatch(boolean strict, int rest) {
 if (rest < 8) {
     return false;
 }

 char c0 = charAt(bp);
 char c1 = charAt(bp + 1);
 char c2 = charAt(bp + 2);
 char c3 = charAt(bp + 3);
 char c4 = charAt(bp + 4);
 char c5 = charAt(bp + 5);
 char c6 = charAt(bp + 6);
 char c7 = charAt(bp + 7);

 if ((!strict) && rest > 13) {
     char c_r0 = charAt(bp + rest - 1);
     char c_r1 = charAt(bp + rest - 2);
 }

 char c10;


 if (rest < 9) {
     return false;
 }

 char c8 = charAt(bp + 8);
 char c9 = charAt(bp + 9);

 int date_len = 10;
 char y0, y1, y2, y3, M0, M1, d0, d1;
 if ((c4 == '-' && c7 == '-') // cn
  ||  (c4 == '/' && c7 == '/') // tw yyyy/mm/dd
 ) {
     y0 = c0;
     y1 = c1;
     y2 = c2;
     y3 = c3;
     M0 = c5;
     M1 = c6;
     d0 = c8;
     d1 = c9;
 } else if ((c4 == '-' && c6 == '-') // cn yyyy-m-dd
 ) {
     y0 = c0;
     y1 = c1;
     y2 = c2;
     y3 = c3;
     M0 = '0';
     M1 = c5;

     if (c8 == ' ') {
  d0 = '0';
  d1 = c7;
  date_len = 8;
     } else {
  d0 = c7;
  d1 = c8;
  date_len = 9;
     }
 } else if ((c2 == '.' && c5 == '.') // de dd.mm.yyyy
  || (c2 == '-' && c5 == '-') // in dd-mm-yyyy
 ) {
     d0 = c0;
     d1 = c1;
     M0 = c3;
     M1 = c4;
     y0 = c6;
     y1 = c7;
     y2 = c8;
     y3 = c9;
 } else if (c8 == 'T') {
     y0 = c0;
     y1 = c1;
     y2 = c2;
     y3 = c3;
     M0 = c4;
     M1 = c5;
     d0 = c6;
     d1 = c7;
     date_len = 8;
 } else {
     if (c4 == '年' || c4 == '년') {
  y0 = c0;
  y1 = c1;
  y2 = c2;
  y3 = c3;

  if (c7 == '月' || c7 == '월') {
      M0 = c5;
      M1 = c6;
      if (c9 == '日' || c9 == '일') {
   d0 = '0';
   d1 = c8;
      } else if (charAt(bp + 10) == '日' || charAt(bp + 10) == '일'){
   d0 = c8;
   d1 = c9;
   date_len = 11;
      } else {
   return false;
      }
  } else if (c6 == '月' || c6 == '월') {
      M0 = '0';
      M1 = c5;
      if (c8 == '日' || c8 == '일') {
   d0 = '0';
   d1 = c7;
      } else if (c9 == '日' || c9 == '일'){
   d0 = c7;
   d1 = c8;
      } else {
   return false;
      }
  } else {
      return false;
  }
     } else {
  return false;
     }
 }

 if (!checkDate(y0, y1, y2, y3, M0, M1, d0, d1)) {
     return false;
 }

 setCalendar(y0, y1, y2, y3, M0, M1, d0, d1);

 char t = charAt(bp + date_len);


 if (charAt(bp + date_len + 3) != ':') {
     return false;
 }
 if (charAt(bp + date_len + 6) != ':') {
     return false;
 }

 char h0 = charAt(bp + date_len + 1);
 char h1 = charAt(bp + date_len + 2);
 char m0 = charAt(bp + date_len + 4);
 char m1 = charAt(bp + date_len + 5);
 char s0 = charAt(bp + date_len + 7);
 char s1 = charAt(bp + date_len + 8);

 if (!checkTime(h0, h1, m0, m1, s0, s1)) {
     return false;
 }

 setTime(h0, h1, m0, m1, s0, s1);

 char dot = charAt(bp + date_len + 9);
 int millisLen = -1; // 有可能没有毫秒区域，没有毫秒区域的时候下一个字符位置有可能是'Z'、'+'、'-'
 int millis = 0;

 calendar.set(Calendar.MILLISECOND, millis);

 int timzeZoneLength = 0;
 char timeZoneFlag = charAt(bp + date_len + 10 + millisLen);

 if (timeZoneFlag == ' ') {
     millisLen++;
     timeZoneFlag = charAt(bp + date_len + 10 + millisLen);
 }

 char end = charAt(bp + (date_len + 10 + millisLen + timzeZoneLength));
 if (end != EOI && end != '"') {
     return false;
 }
 ch = charAt(bp += (date_len + 10 + millisLen + timzeZoneLength));

 token = JSONToken.LITERAL_ISO8601_DATE;
 return true;
    }