Mega Code Archive
Implement SimpleDateFormat for GWT
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/*
* Copyright 2006 Robert Hanson <iamroberthanson AT gmail.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.gwtwidgets.client.util;
import java.util.Date;
/**
* <dl>
* <dt><b>Title: </b>
* <dd>SimpleDateFormat</dd>
* <p>
* <dt><b>Description: </b>
* <dd>GWT does not implement any of the java.text package, so this class tries
* to fill the void of the missing java.text.SimpleDateFormat class. This
* version however only supports a subset of the date and time patterns
* supported by its java.text counterpart. The pattern symbols supported by this
* class are:
* <dl>
* <dt><b>E</b></dt>
* <dd>Day in a week</dd>
* <dt><b>d</b></dt>
* <dd>Day of the month</dd>
* <dt><b>y</b></dt>
* <dd>Year</dd>
* <dt><b>M</b></dt>
* <dd>Month January, Jan, 01, 1</dd>
* <dt><b>H</b></dt>
* <dd>Hour in 24 hour format (0-23)</dd>
* <dt><b>h</b></dt>
* <dd>Hour in 12 hour format (1-12)</dd>
* <dt><b>m</b></dt>
* <dd>Minute of the hour </dd>
* <dt><b>s</b></dt>
* <dd>Seconds of the minute</dd>
* <dt><b>a</b></dt>
* <dd>am/pm</dd>
* </dl>
* All characters that are not recognised as a date format character are
* translated literally into the output string. <br/> </dd>
* <p>
* </dl>
* <p>
* A simple date parsing facility has also been implemented resembling the java
* prototype. You can currently parse most numeric patterns but no temporal
* literals (such as day or month names).
* </p>
*
* @author <a href="mailto:jasone@greenrivercomputing.com">Jason Essington</a>
* @author <a href="mailto:g.georgovassilis@gmail.com">George Georgovassilis</a>
* @version $Revision: 0.0 $
*/
public class SimpleDateFormat {
private String format;
private DateLocale locale = new DateLocale();
/**
* Gets the support locale for formatting and parsing dates
* @return
*/
public DateLocale getLocale() {
return locale;
}
public void setLocale(DateLocale locale) {
this.locale = locale;
}
public SimpleDateFormat(String pattern) {
format = pattern;
}
public String format(Date date) {
String f = "";
if (format != null && format.length() > 0) {
String lastTokenType = null;
String currentToken = "";
for (int i = 0; i < format.length(); i++) {
String thisChar = format.substring(i, i + 1);
String currentTokenType = DateLocale.SUPPORTED_DF_TOKENS
.contains(thisChar) ? thisChar : "";
if (currentTokenType.equals(lastTokenType) || i == 0) {
currentToken += thisChar;
lastTokenType = currentTokenType;
} else {
if ("".equals(lastTokenType))
f += currentToken;
else
f += handleToken(currentToken, date);
currentToken = thisChar;
lastTokenType = currentTokenType;
}
}
if ("".equals(lastTokenType))
f += currentToken;
else
f += handleToken(currentToken, date);
}
return f;
}
/**
* takes a date format string and returns the formatted portion of the date.
* For instance if the token is MMMM then the full month name is returned.
*
* @param token
* date format token
* @param date
* date to format
* @return formatted portion of the date
*/
private String handleToken(String token, Date date) {
String response = token;
String tc = token.substring(0, 1);
if (DateLocale.TOKEN_DAY_OF_WEEK.equals(tc)) {
if (token.length() > 3)
response = locale.getWEEKDAY_LONG()[date.getDay()];
else
response = locale.getWEEKDAY_SHORT()[date.getDay()];
} else if (DateLocale.TOKEN_DAY_OF_MONTH.equals(tc)) {
if (token.length() == 1)
response = Integer.toString(date.getDate());
else
response = twoCharDateField(date.getDate());
} else if (DateLocale.TOKEN_MONTH.equals(tc)) {
switch (token.length()) {
case 1:
response = Integer.toString(date.getMonth() + 1);
break;
case 2:
response = twoCharDateField(date.getMonth() + 1);
break;
case 3:
response = locale.MONTH_SHORT[date.getMonth()];
break;
default:
response = locale.MONTH_LONG[date.getMonth()];
break;
}
} else if (DateLocale.TOKEN_YEAR.equals(tc)) {
if (token.length() > 2)
response = Integer.toString(date.getYear() + 1900);
else
response = twoCharDateField(date.getYear());
} else if (DateLocale.TOKEN_HOUR_12.equals(tc)) {
int h = date.getHours();
if (h == 0)
h = 12;
else if (h > 12)
h -= 12;
if (token.length() > 1)
response = twoCharDateField(h);
else
response = Integer.toString(h);
} else if (DateLocale.TOKEN_HOUR_24.equals(tc)) {
if (token.length() > 1)
response = twoCharDateField(date.getHours());
else
response = Integer.toString(date.getHours());
} else if (DateLocale.TOKEN_MINUTE.equals(tc)) {
if (token.length() > 1)
response = twoCharDateField(date.getMinutes());
else
response = Integer.toString(date.getMinutes());
} else if (DateLocale.TOKEN_SECOND.equals(tc)) {
if (token.length() > 1)
response = twoCharDateField(date.getSeconds());
else
response = Integer.toString(date.getSeconds());
} else if (DateLocale.TOKEN_AM_PM.equals(tc)) {
int hour = date.getHours();
if (hour > 11)
response = DateLocale.getPM();
else
response = DateLocale.getAM();
}
return response;
}
/**
* This is basically just a sneaky way to guarantee that our 1 or 2 digit
* numbers come out as a 2 character string. we add an arbitrary number
* larger than 100, convert this new number to a string, then take the right
* most 2 characters.
*
* @param num
* @return
*/
private String twoCharDateField(int num) {
String res = Integer.toString(num + 1900);
res = res.substring(res.length() - 2);
return res;
}
private static Date newDate(long time) {
return new Date(time);
}
/**
* Parses text and returns the corresponding date object.
*
* @param source
* @return java.util.Date
*/
public Date parse(String source){
return SimpleDateParser.parse(source, format);
};
}
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