Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 javadz.beanutils.converters; import java.util.Date; import java.util.Locale; import java.util.Calendar; import java.util.TimeZone; import java.text.DateFormat; import java.text.SimpleDateFormat; import java.text.ParsePosition; import javadz.beanutils.ConversionException; /** * {@link org.apache.commons.beanutils.Converter} implementaion * that handles conversion to and from <b>date/time</b> objects. * <p> * This implementation handles conversion for the following * <i>date/time</i> types. * <ul> * <li><code>java.util.Date</code></li> * <li><code>java.util.Calendar</code></li> * <li><code>java.sql.Date</code></li> * <li><code>java.sql.Time</code></li> * <li><code>java.sql.Timestamp</code></li> * </ul> * * <h3>String Conversions (to and from)</h3> * This class provides a number of ways in which date/time * conversions to/from Strings can be achieved: * <ul> * <li>Using the SHORT date format for the default Locale, configure using:</li> * <ul> * <li><code>setUseLocaleFormat(true)</code></li> * </ul> * <li>Using the SHORT date format for a specified Locale, configure using:</li> * <ul> * <li><code>setLocale(Locale)</code></li> * </ul> * <li>Using the specified date pattern(s) for the default Locale, configure using:</li> * <ul> * <li>Either <code>setPattern(String)</code> or * <code>setPatterns(String[])</code></li> * </ul> * <li>Using the specified date pattern(s) for a specified Locale, configure using:</li> * <ul> * <li><code>setPattern(String)</code> or * <code>setPatterns(String[]) and...</code></li> * <li><code>setLocale(Locale)</code></li> * </ul> * <li>If none of the above are configured the * <code>toDate(String)</code> method is used to convert * from String to Date and the Dates's * <code>toString()</code> method used to convert from * Date to String.</li> * </ul> * * <p> * The <b>Time Zone</b> to use with the date format can be specified * using the <code>setTimeZone()</code> method. * * @version $Revision: 640131 $ $Date: 2008-03-23 02:10:31 +0000 (Sun, 23 Mar 2008) $ * @since 1.8.0 */ public abstract class DateTimeConverter extends AbstractConverter { private String[] patterns; private String displayPatterns; private Locale locale; private TimeZone timeZone; private boolean useLocaleFormat; // ----------------------------------------------------------- Constructors /** * Construct a Date/Time <i>Converter</i> that throws a * <code>ConversionException</code> if an error occurs. */ public DateTimeConverter() { super(); } /** * Construct a Date/Time <i>Converter</i> that returns a default * value if an error occurs. * * @param defaultValue The default value to be returned * if the value to be converted is missing or an error * occurs converting the value. */ public DateTimeConverter(Object defaultValue) { super(defaultValue); } // --------------------------------------------------------- Public Methods /** * Indicate whether conversion should use a format/pattern or not. * * @param useLocaleFormat <code>true</code> if the format * for the locale should be used, otherwise <code>false</code> */ public void setUseLocaleFormat(boolean useLocaleFormat) { this.useLocaleFormat = useLocaleFormat; } /** * Return the Time Zone to use when converting dates * (or <code>null</code> if none specified. * * @return The Time Zone. */ public TimeZone getTimeZone() { return timeZone; } /** * Set the Time Zone to use when converting dates. * * @param timeZone The Time Zone. */ public void setTimeZone(TimeZone timeZone) { this.timeZone = timeZone; } /** * Return the Locale for the <i>Converter</i> * (or <code>null</code> if none specified). * * @return The locale to use for conversion */ public Locale getLocale() { return locale; } /** * Set the Locale for the <i>Converter</i>. * * @param locale The Locale. */ public void setLocale(Locale locale) { this.locale = locale; setUseLocaleFormat(true); } /** * Set a date format pattern to use to convert * dates to/from a <code>java.lang.String</code>. * * @see SimpleDateFormat * @param pattern The format pattern. */ public void setPattern(String pattern) { setPatterns(new String[] { pattern }); } /** * Return the date format patterns used to convert * dates to/from a <code>java.lang.String</code> * (or <code>null</code> if none specified). * * @see SimpleDateFormat * @return Array of format patterns. */ public String[] getPatterns() { return patterns; } /** * Set the date format patterns to use to convert * dates to/from a <code>java.lang.String</code>. * * @see SimpleDateFormat * @param patterns Array of format patterns. */ public void setPatterns(String[] patterns) { this.patterns = patterns; if (patterns != null && patterns.length > 1) { StringBuffer buffer = new StringBuffer(); for (int i = 0; i < patterns.length; i++) { if (i > 0) { buffer.append(", "); } buffer.append(patterns[i]); } displayPatterns = buffer.toString(); } setUseLocaleFormat(true); } // ------------------------------------------------------ Protected Methods /** * Convert an input Date/Calendar object into a String. * <p> * <b>N.B.</b>If the converter has been configured to with * one or more patterns (using <code>setPatterns()</code>), then * the first pattern will be used to format the date into a String. * Otherwise the default <code>DateFormat</code> for the default locale * (and <i>style</i> if configured) will be used. * * @param value The input value to be converted * @return the converted String value. * @throws Throwable if an error occurs converting to a String */ protected String convertToString(Object value) throws Throwable { Date date = null; if (value instanceof Date) { date = (Date) value; } else if (value instanceof Calendar) { date = ((Calendar) value).getTime(); } else if (value instanceof Long) { date = new Date(((Long) value).longValue()); } String result = null; if (useLocaleFormat && date != null) { DateFormat format = null; if (patterns != null && patterns.length > 0) { format = getFormat(patterns[0]); } else { format = getFormat(locale, timeZone); } logFormat("Formatting", format); result = format.format(date); if (log().isDebugEnabled()) { log().debug(" Converted to String using format '" + result + "'"); } } else { result = value.toString(); if (log().isDebugEnabled()) { log().debug(" Converted to String using toString() '" + result + "'"); } } return result; } /** * Convert the input object into a Date object of the * specified type. * <p> * This method handles conversions between the following * types: * <ul> * <li><code>java.util.Date</code></li> * <li><code>java.util.Calendar</code></li> * <li><code>java.sql.Date</code></li> * <li><code>java.sql.Time</code></li> * <li><code>java.sql.Timestamp</code></li> * </ul> * * It also handles conversion from a <code>String</code> to * any of the above types. * <p> * * For <code>String</code> conversion, if the converter has been configured * with one or more patterns (using <code>setPatterns()</code>), then * the conversion is attempted with each of the specified patterns. * Otherwise the default <code>DateFormat</code> for the default locale * (and <i>style</i> if configured) will be used. * * @param targetType Data type to which this value should be converted. * @param value The input value to be converted. * @return The converted value. * @throws Exception if conversion cannot be performed successfully */ protected Object convertToType(Class targetType, Object value) throws Exception { Class sourceType = value.getClass(); // Handle java.sql.Timestamp if (value instanceof java.sql.Timestamp) { // ---------------------- JDK 1.3 Fix ---------------------- // N.B. Prior to JDK 1.4 the Timestamp's getTime() method // didn't include the milliseconds. The following code // ensures it works consistently accross JDK versions java.sql.Timestamp timestamp = (java.sql.Timestamp) value; long timeInMillis = ((timestamp.getTime() / 1000) * 1000); timeInMillis += timestamp.getNanos() / 1000000; // ---------------------- JDK 1.3 Fix ---------------------- return toDate(targetType, timeInMillis); } // Handle Date (includes java.sql.Date & java.sql.Time) if (value instanceof Date) { Date date = (Date) value; return toDate(targetType, date.getTime()); } // Handle Calendar if (value instanceof Calendar) { Calendar calendar = (Calendar) value; return toDate(targetType, calendar.getTime().getTime()); } // Handle Long if (value instanceof Long) { Long longObj = (Long) value; return toDate(targetType, longObj.longValue()); } // Convert all other types to String & handle String stringValue = value.toString().trim(); if (stringValue.length() == 0) { return handleMissing(targetType); } // Parse the Date/Time if (useLocaleFormat) { Calendar calendar = null; if (patterns != null && patterns.length > 0) { calendar = parse(sourceType, targetType, stringValue); } else { DateFormat format = getFormat(locale, timeZone); calendar = parse(sourceType, targetType, stringValue, format); } if (Calendar.class.isAssignableFrom(targetType)) { return calendar; } else { return toDate(targetType, calendar.getTime().getTime()); } } // Default String conversion return toDate(targetType, stringValue); } /** * Convert a long value to the specified Date type for this * <i>Converter</i>. * <p> * * This method handles conversion to the following types: * <ul> * <li><code>java.util.Date</code></li> * <li><code>java.util.Calendar</code></li> * <li><code>java.sql.Date</code></li> * <li><code>java.sql.Time</code></li> * <li><code>java.sql.Timestamp</code></li> * </ul> * * @param type The Date type to convert to * @param value The long value to convert. * @return The converted date value. */ private Object toDate(Class type, long value) { // java.util.Date if (type.equals(Date.class)) { return new Date(value); } // java.sql.Date if (type.equals(java.sql.Date.class)) { return new java.sql.Date(value); } // java.sql.Time if (type.equals(java.sql.Time.class)) { return new java.sql.Time(value); } // java.sql.Timestamp if (type.equals(java.sql.Timestamp.class)) { return new java.sql.Timestamp(value); } // java.util.Calendar if (type.equals(Calendar.class)) { Calendar calendar = null; if (locale == null && timeZone == null) { calendar = Calendar.getInstance(); } else if (locale == null) { calendar = Calendar.getInstance(timeZone); } else if (timeZone == null) { calendar = Calendar.getInstance(locale); } else { calendar = Calendar.getInstance(timeZone, locale); } calendar.setTime(new Date(value)); calendar.setLenient(false); return calendar; } String msg = toString(getClass()) + " cannot handle conversion to '" + toString(type) + "'"; if (log().isWarnEnabled()) { log().warn(" " + msg); } throw new ConversionException(msg); } /** * Default String to Date conversion. * <p> * This method handles conversion from a String to the following types: * <ul> * <li><code>java.sql.Date</code></li> * <li><code>java.sql.Time</code></li> * <li><code>java.sql.Timestamp</code></li> * </ul> * <p> * <strong>N.B.</strong> No default String conversion * mechanism is provided for <code>java.util.Date</code> * and <code>java.util.Calendar</code> type. * * @param type The Number type to convert to * @param value The String value to convert. * @return The converted Number value. */ private Object toDate(Class type, String value) { // java.sql.Date if (type.equals(java.sql.Date.class)) { try { return java.sql.Date.valueOf(value); } catch (IllegalArgumentException e) { throw new ConversionException( "String must be in JDBC format [yyyy-MM-dd] to create a java.sql.Date"); } } // java.sql.Time if (type.equals(java.sql.Time.class)) { try { return java.sql.Time.valueOf(value); } catch (IllegalArgumentException e) { throw new ConversionException("String must be in JDBC format [HH:mm:ss] to create a java.sql.Time"); } } // java.sql.Timestamp if (type.equals(java.sql.Timestamp.class)) { try { return java.sql.Timestamp.valueOf(value); } catch (IllegalArgumentException e) { throw new ConversionException("String must be in JDBC format [yyyy-MM-dd HH:mm:ss.fffffffff] " + "to create a java.sql.Timestamp"); } } String msg = toString(getClass()) + " does not support default String to '" + toString(type) + "' conversion."; if (log().isWarnEnabled()) { log().warn(" " + msg); log().warn(" (N.B. Re-configure Converter or use alternative implementation)"); } throw new ConversionException(msg); } /** * Return a <code>DateFormat<code> for the Locale. * @param locale The Locale to create the Format with (may be null) * @param timeZone The Time Zone create the Format with (may be null) * * @return A Date Format. */ protected DateFormat getFormat(Locale locale, TimeZone timeZone) { DateFormat format = null; if (locale == null) { format = DateFormat.getDateInstance(DateFormat.SHORT); } else { format = DateFormat.getDateInstance(DateFormat.SHORT, locale); } if (timeZone != null) { format.setTimeZone(timeZone); } return format; } /** * Create a date format for the specified pattern. * * @param pattern The date pattern * @return The DateFormat */ private DateFormat getFormat(String pattern) { DateFormat format = new SimpleDateFormat(pattern); if (timeZone != null) { format.setTimeZone(timeZone); } return format; } /** * Parse a String date value using the set of patterns. * * @param sourceType The type of the value being converted * @param targetType The type to convert the value to. * @param value The String date value. * * @return The converted Date object. * @throws Exception if an error occurs parsing the date. */ private Calendar parse(Class sourceType, Class targetType, String value) throws Exception { Exception firstEx = null; for (int i = 0; i < patterns.length; i++) { try { DateFormat format = getFormat(patterns[i]); Calendar calendar = parse(sourceType, targetType, value, format); return calendar; } catch (Exception ex) { if (firstEx == null) { firstEx = ex; } } } if (patterns.length > 1) { throw new ConversionException("Error converting '" + toString(sourceType) + "' to '" + toString(targetType) + "' using patterns '" + displayPatterns + "'"); } else { throw firstEx; } } /** * Parse a String into a <code>Calendar</code> object * using the specified <code>DateFormat</code>. * * @param sourceType The type of the value being converted * @param targetType The type to convert the value to * @param value The String date value. * @param format The DateFormat to parse the String value. * * @return The converted Calendar object. * @throws ConversionException if the String cannot be converted. */ private Calendar parse(Class sourceType, Class targetType, String value, DateFormat format) { logFormat("Parsing", format); format.setLenient(false); ParsePosition pos = new ParsePosition(0); Date parsedDate = format.parse(value, pos); // ignore the result (use the Calendar) if (pos.getErrorIndex() >= 0 || pos.getIndex() != value.length() || parsedDate == null) { String msg = "Error converting '" + toString(sourceType) + "' to '" + toString(targetType) + "'"; if (format instanceof SimpleDateFormat) { msg += " using pattern '" + ((SimpleDateFormat) format).toPattern() + "'"; } if (log().isDebugEnabled()) { log().debug(" " + msg); } throw new ConversionException(msg); } Calendar calendar = format.getCalendar(); return calendar; } /** * Provide a String representation of this date/time converter. * * @return A String representation of this date/time converter */ public String toString() { StringBuffer buffer = new StringBuffer(); buffer.append(toString(getClass())); buffer.append("[UseDefault="); buffer.append(isUseDefault()); buffer.append(", UseLocaleFormat="); buffer.append(useLocaleFormat); if (displayPatterns != null) { buffer.append(", Patterns={"); buffer.append(displayPatterns); buffer.append('}'); } if (locale != null) { buffer.append(", Locale="); buffer.append(locale); } if (timeZone != null) { buffer.append(", TimeZone="); buffer.append(timeZone); } buffer.append(']'); return buffer.toString(); } /** * Log the <code>DateFormat<code> creation. * @param action The action the format is being used for * @param format The Date format */ private void logFormat(String action, DateFormat format) { if (log().isDebugEnabled()) { StringBuffer buffer = new StringBuffer(45); buffer.append(" "); buffer.append(action); buffer.append(" with Format"); if (format instanceof SimpleDateFormat) { buffer.append("["); buffer.append(((SimpleDateFormat) format).toPattern()); buffer.append("]"); } buffer.append(" for "); if (locale == null) { buffer.append("default locale"); } else { buffer.append("locale["); buffer.append(locale); buffer.append("]"); } if (timeZone != null) { buffer.append(", TimeZone["); buffer.append(timeZone); buffer.append("]"); } log().debug(buffer.toString()); } } }