1 files changed, 326 insertions, 0 deletions
diff --git a/common/src/at/gv/egovernment/moa/util/DateTimeUtils.java b/common/src/at/gv/egovernment/moa/util/DateTimeUtils.java
new file mode 100644
index 000000000..58cc04c4c
--- /dev/null
+++ b/common/src/at/gv/egovernment/moa/util/DateTimeUtils.java
@@ -0,0 +1,326 @@
+package at.gv.egovernment.moa.util;
+
+import java.io.StringWriter;
+import java.text.ParseException;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.GregorianCalendar;
+import java.util.TimeZone;
+
+/**
+ * Utility for parsing and building XML type <code>dateTime</code>,
+ * according to ISO 8601.
+ * 
+ * @author Patrick Peck
+ * @version $Id$
+ * @see <code>http://www.w3.org/2001/XMLSchema-datatypes"</code>
+ */
+public class DateTimeUtils {
+  /** Error messages. */
+  private static MessageProvider msg = MessageProvider.getInstance();
+
+  /**
+   * Builds a <code>dateTime</code> value from a <code>Calendar</code> value.
+   * @param cal the <code>Calendar</code> value
+   * @return the <code>dateTime</code> value
+   */
+  public static String buildDateTime(Calendar cal) {
+    StringWriter out = new StringWriter();
+    out.write("" + cal.get(Calendar.YEAR));
+    out.write("-");
+    out.write(to2DigitString(cal.get(Calendar.MONTH) + 1));
+    out.write("-");
+    out.write(to2DigitString(cal.get(Calendar.DAY_OF_MONTH)));
+    out.write("T");
+    out.write(to2DigitString(cal.get(Calendar.HOUR_OF_DAY)));
+    out.write(":");
+    out.write(to2DigitString(cal.get(Calendar.MINUTE)));
+    out.write(":");
+    out.write(to2DigitString(cal.get(Calendar.SECOND)));
+    int tzOffsetMilliseconds =
+      cal.get(Calendar.ZONE_OFFSET) + cal.get(Calendar.DST_OFFSET);
+    if (tzOffsetMilliseconds != 0) {
+      int tzOffsetMinutes = tzOffsetMilliseconds / (1000 * 60);
+      int tzOffsetHours = tzOffsetMinutes / 60;
+      tzOffsetMinutes -= tzOffsetHours * 60;
+      if (tzOffsetMilliseconds > 0) {
+        out.write("+");
+        out.write(to2DigitString(tzOffsetHours));
+        out.write(":");
+        out.write(to2DigitString(tzOffsetMinutes));
+      } else {
+        out.write("-");
+        out.write(to2DigitString(-tzOffsetHours));
+        out.write(":");
+        out.write(to2DigitString(-tzOffsetMinutes));
+      }
+    }
+    return out.toString();
+  }
+  
+  /**
+   * Converts month, day, hour, minute, or second value
+   * to a 2 digit String.
+   * @param number the month, day, hour, minute, or second value
+   * @return 2 digit String
+   */
+  private static String to2DigitString(int number) {
+    if (number < 10)
+      return "0" + number;
+    else
+      return "" + number;
+  }
+
+  /**
+   * Parse a <code>String</code> containing a date and time instant, given in
+   * ISO 8601 format.
+   * 
+   * @param dateTime The <code>String</code> to parse.
+   * @return The <code>Date</code> representation of the contents of
+   * <code>dateTime</code>.
+   * @throws ParseException Parsing the <code>dateTime</code> failed.
+   */
+  public static Date parseDateTime(String dateTime) throws ParseException {
+    GregorianCalendar calendar;
+    long time;
+    int yearSign = 1, year, month, day;
+    int hour, minute, second;
+    double fraction = 0.0;
+    int tzSign = 1, tzHour = 0, tzMinute = 0;
+    int curPos = 0;
+    String fractStr;
+    boolean localTime = false;
+    char c;
+
+    // parse year sign
+    ensureChars(dateTime, curPos, 1);
+    c = dateTime.charAt(curPos);
+    if (c == '+' || c == '-') {
+      yearSign = c == '+' ? 1 : -1;
+      curPos++;
+    }
+
+    // parse year
+    year = parseInt(dateTime, curPos, 4);
+    curPos += 4;
+
+    // parse '-'
+    ensureChar(dateTime, curPos, '-');
+    curPos++;
+
+    // parse month
+    month = parseInt(dateTime, curPos, 2);
+    ensureValue(month, 1, 12, curPos);
+    curPos += 2;
+
+    // parse '-'
+    ensureChar(dateTime, curPos, '-');
+    curPos++;
+
+    // parse day
+    day = parseInt(dateTime, curPos, 2);
+    ensureValue(day, 1, 31, curPos);
+    curPos += 2;
+
+    // parse 'T'
+    ensureChar(dateTime, curPos, 'T');
+    curPos++;
+
+    // parse hour
+    hour = parseInt(dateTime, curPos, 2);
+    ensureValue(hour, 0, 23, curPos);
+    curPos += 2;
+
+    // parse ':'
+    ensureChar(dateTime, curPos, ':');
+    curPos++;
+
+    // parse minute
+    minute = parseInt(dateTime, curPos, 2);
+    ensureValue(minute, 0, 59, curPos);
+    curPos += 2;
+
+    // parse ':'
+    ensureChar(dateTime, curPos, ':');
+    curPos++;
+
+    // parse second
+    second = parseInt(dateTime, curPos, 2);
+    ensureValue(second, 0, 59, curPos);
+    curPos += 2;
+
+    // parse a fraction
+    if (dateTime.length() > curPos && dateTime.charAt(curPos) == '.') {
+      curPos++;
+      ensureDigits(dateTime, curPos, 1);
+      fractStr = "0.";
+      fractStr
+        += dateTime.substring(curPos, curPos + countDigits(dateTime, curPos));
+      fraction = Double.parseDouble(fractStr);
+      curPos += countDigits(dateTime, curPos);
+    }
+
+    // parse a time zone
+    if (dateTime.length() > curPos) {
+      c = dateTime.charAt(curPos);
+      if (c == 'Z') {
+        curPos++;
+      } else if (c == '+' || c == '-') {
+        // parse time zone sign
+        tzSign = c == '+' ? 1 : -1;
+        curPos++;
+
+        // parse time zone hour
+        tzHour = parseInt(dateTime, curPos, 2);
+        ensureValue(tzHour, 0, 14, curPos);
+        curPos += 2;
+
+        // parse ':'
+        ensureChar(dateTime, curPos, ':');
+        curPos++;
+
+        // parse time zone minute
+        tzMinute = parseInt(dateTime, curPos, 2);
+        ensureValue(tzMinute, 0, 59, curPos);
+        curPos += 2;
+      }
+    } else {
+      localTime = true;
+    }
+
+    // if we have characters left, it's an error
+    if (dateTime.length() != curPos) {
+      throw new ParseException(msg.getMessage("datetime.00", null), curPos);
+    }
+
+    // build the Date object
+    year = year * yearSign;
+    try {
+      calendar = new GregorianCalendar(TimeZone.getTimeZone("GMT"));
+      calendar.set(year, month - 1, day, hour, minute, second);
+      calendar.set(Calendar.MILLISECOND, 0);
+      time = calendar.getTime().getTime();
+      time += (long) (fraction * 1000.0);
+      time -= tzSign * ((tzHour * 60) + tzMinute) * 60 * 1000;
+      if (localTime) {
+        time -= TimeZone.getDefault().getRawOffset();        
+      }
+      return new Date(time);
+    } catch (IllegalArgumentException e) {
+      throw new ParseException(msg.getMessage("datetime.00", null), curPos);
+    }
+
+  }
+
+  /**
+   * Parse an integer value.
+   * 
+   * @param str The <code>String</code> containing the digits.
+   * @param curPos The starting position.
+   * @param digits The number of digist making up the integer value.
+   * @return int The integer representation of the digits contained in
+   * <code>str</code>.
+   * @throws ParseException Parsing the integer value failed.
+   */
+  private static int parseInt(String str, int curPos, int digits)
+    throws ParseException {
+
+    ensureDigits(str, curPos, digits);
+    return Integer.parseInt(str.substring(curPos, curPos + digits));
+  }
+
+  /**
+   * Count the number of digits following <code>curPos</code>.
+   * 
+   * @param str The <code>String</code> in which to count digits.
+   * @param curPos The starting position.
+   * @return int The number of digits.
+   */
+  private static int countDigits(String str, int curPos) {
+    int i;
+
+    for (i = curPos; i < str.length() && Character.isDigit(str.charAt(i)); i++);
+    return i - curPos;
+  }
+
+  /**
+   * Ensure that a value falls in a given min/max range.
+   * 
+   * @param value The value to check.
+   * @param min The minimum allowed value.
+   * @param max The maximum allowed value.
+   * @param curPos To indicate the parsing position in the
+   * <code>ParseException</code>.
+   * @throws ParseException Thrown, if <code>value &lt; min || value &gt;
+   * max</code>
+   */
+  private static void ensureValue(int value, int min, int max, int curPos)
+    throws ParseException {
+
+    if (value < min || value > max) {
+      throw new ParseException(msg.getMessage("datetime.00", null), curPos);
+    }
+  }
+
+  /**
+   * Ensure that the given <code>String</code> has a number of characters left.
+   * 
+   * @param str The <code>String</code> to check for its length.
+   * @param curPos The starting position.
+   * @param count The minimum number of characters that <code>str</code> must
+   * contain, starting at from <code>curPos</code>.
+   * @throws ParseException Thrown, if 
+   * <code>curPos + count &gt; str.length()</code>.
+   */
+  private static void ensureChars(String str, int curPos, int count)
+    throws ParseException {
+    if (curPos + count > str.length()) {
+      throw new ParseException(msg.getMessage("datetime.00", null), curPos);
+    }
+  }
+
+  /**
+   * Ensure that a given <code>String</code> contains a certain character at a
+   * certain position.
+   * 
+   * @param str The <code>String</code> in which to look up the character. 
+   * @param curPos The position in <code>str</code> that must contain the
+   * character.
+   * @param c The character value that must be contained at position
+   * <code>curPos</code>.
+   * @throws ParseException Thrown, if the characters do not match or
+   * <code>curPos</code> is out of range.
+   */
+  private static void ensureChar(String str, int curPos, char c)
+    throws ParseException {
+
+    ensureChars(str, curPos, 1);
+    if (str.charAt(curPos) != c) {
+      throw new ParseException(msg.getMessage("datetime.00", null), curPos);
+    }
+  }
+
+  /**
+   * Ensure that a given <code>String</code> contains a number of digits,
+   * starting at a given position.
+   * 
+   * @param str The <code>String</code> to scan for digits. 
+   * @param curPos The starting postion.
+   * @param count The number of digits that must be contained in
+   * <code>str</code>, starting at <code>curPos</code>.
+   * @throws ParseException Thrown, if <code>str</code> is not long enough, or
+   * one of the characters following <code>curPos</code> in <code>str</code> is
+   * not a digit.
+   */
+  private static void ensureDigits(String str, int curPos, int count)
+    throws ParseException {
+
+    ensureChars(str, curPos, count);
+    for (int i = curPos; i < curPos + count; i++) {
+      if (!Character.isDigit(str.charAt(i))) {
+        throw new ParseException(msg.getMessage("datetime.00", null), curPos);
+      }
+    }
+  }
+
+}