datelocaleconverter.java

JAVA 文章管理系统源码

/*
 * Copyright 2001-2004 The Apache Software Foundation.
 * 
 * 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.apache.commons.beanutils.locale.converters;

import org.apache.commons.beanutils.locale.BaseLocaleConverter;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.Log;

import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Locale;


/**
 * <p>Standard {@link org.apache.commons.beanutils.locale.LocaleConverter} 
 * implementation that converts an incoming
 * locale-sensitive String into a <code>java.util.Date</code> object,
 * optionally using a default value or throwing a 
 * {@link org.apache.commons.beanutils.ConversionException}
 * if a conversion error occurs.</p>
 *
 * @author Yauheny Mikulski
 * @author Michael Szlapa
 */

public class DateLocaleConverter extends BaseLocaleConverter {

    // ----------------------------------------------------- Instance Variables

    /** All logging goes through this logger */
    private static Log log = LogFactory.getLog(DateLocaleConverter.class);

    /** Should the date conversion be lenient? */
    boolean isLenient = false;

    // ----------------------------------------------------------- Constructors

    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will throw a {@link org.apache.commons.beanutils.ConversionException}
     * if a conversion error occurs. The locale is the default locale for
     * this instance of the Java Virtual Machine and an unlocalized pattern is used
     * for the convertion.
     *
     */
    public DateLocaleConverter() {

        this(false);
    }

    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will throw a {@link org.apache.commons.beanutils.ConversionException}
     * if a conversion error occurs. The locale is the default locale for
     * this instance of the Java Virtual Machine.
     *
     * @param locPattern    Indicate whether the pattern is localized or not
     */
    public DateLocaleConverter(boolean locPattern) {

        this(Locale.getDefault(), locPattern);
    }

    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will throw a {@link org.apache.commons.beanutils.ConversionException}
     * if a conversion error occurs. An unlocalized pattern is used for the convertion.
     *
     * @param locale        The locale
     */
    public DateLocaleConverter(Locale locale) {

        this(locale, false);
    }

    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will throw a {@link org.apache.commons.beanutils.ConversionException}
     * if a conversion error occurs.
     *
     * @param locale        The locale
     * @param locPattern    Indicate whether the pattern is localized or not
     */
    public DateLocaleConverter(Locale locale, boolean locPattern) {

        this(locale, (String) null, locPattern);
    }

    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will throw a {@link org.apache.commons.beanutils.ConversionException}
     * if a conversion error occurs. An unlocalized pattern is used for the convertion.
     *
     * @param locale        The locale
     * @param pattern       The convertion pattern
     */
    public DateLocaleConverter(Locale locale, String pattern) {

        this(locale, pattern, false);
    }

    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will throw a {@link org.apache.commons.beanutils.ConversionException}
     * if a conversion error occurs.
     *
     * @param locale        The locale
     * @param pattern       The convertion pattern
     * @param locPattern    Indicate whether the pattern is localized or not
     */
    public DateLocaleConverter(Locale locale, String pattern, boolean locPattern) {

        super(locale, pattern, locPattern);
    }

    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will return the specified default value
     * if a conversion error occurs. The locale is the default locale for
     * this instance of the Java Virtual Machine and an unlocalized pattern is used
     * for the convertion.
     *
     * @param defaultValue  The default value to be returned
     */
    public DateLocaleConverter(Object defaultValue) {

        this(defaultValue, false);
    }

    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will return the specified default value
     * if a conversion error occurs. The locale is the default locale for
     * this instance of the Java Virtual Machine.
     *
     * @param defaultValue  The default value to be returned
     * @param locPattern    Indicate whether the pattern is localized or not
     */
    public DateLocaleConverter(Object defaultValue, boolean locPattern) {

        this(defaultValue, Locale.getDefault(), locPattern);
    }

    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will return the specified default value
     * if a conversion error occurs. An unlocalized pattern is used for the convertion.
     *
     * @param defaultValue  The default value to be returned
     * @param locale        The locale
     */
    public DateLocaleConverter(Object defaultValue, Locale locale) {

        this(defaultValue, locale, false);
    }

    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will return the specified default value
     * if a conversion error occurs.
     *
     * @param defaultValue  The default value to be returned
     * @param locale        The locale
     * @param locPattern    Indicate whether the pattern is localized or not
     */
    public DateLocaleConverter(Object defaultValue, Locale locale, boolean locPattern) {

        this(defaultValue, locale, null, locPattern);
    }


    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will return the specified default value
     * if a conversion error occurs. An unlocalized pattern is used for the convertion.
     *
     * @param defaultValue  The default value to be returned
     * @param locale        The locale
     * @param pattern       The convertion pattern
     */
    public DateLocaleConverter(Object defaultValue, Locale locale, String pattern) {

        this(defaultValue, locale, pattern, false);
    }

    /**
     * Create a {@link org.apache.commons.beanutils.locale.LocaleConverter} 
     * that will return the specified default value
     * if a conversion error occurs.
     *
     * @param defaultValue  The default value to be returned
     * @param locale        The locale
     * @param pattern       The convertion pattern
     * @param locPattern    Indicate whether the pattern is localized or not
     */
    public DateLocaleConverter(Object defaultValue, Locale locale, String pattern, boolean locPattern) {

        super(defaultValue, locale, pattern, locPattern);
    }

    // --------------------------------------------------------- Methods
    
    /**
     * Returns whether date formatting is lenient.
     *
     * @return true if the <code>DateFormat</code> used for formatting is lenient
     * @see java.text.DateFormat#isLenient
     */
    public boolean isLenient() {
        return isLenient;
    }
    
    /**
     * Specify whether or not date-time parsing should be lenient.
     * 
     * @param lenient true if the <code>DateFormat</code> used for formatting should be lenient
     * @see java.text.DateFormat#setLenient
     */
    public void setLenient(boolean lenient) {
        isLenient = lenient;
    }	

    // --------------------------------------------------------- Methods

    /**
     * Convert the specified locale-sensitive input object into an output object of the
     * specified type.
     *
     * @param value The input object to be converted
     * @param pattern The pattern is used for the convertion
     *
     * @exception org.apache.commons.beanutils.ConversionException if conversion cannot be performed
     *  successfully
     */
    protected Object parse(Object value, String pattern) throws ParseException {
        SimpleDateFormat formatter = getFormatter(pattern, locale);
        if (locPattern) {
            formatter.applyLocalizedPattern(pattern);
        }
        else {
            formatter.applyPattern(pattern);
        }
        return formatter.parse((String) value);
    }

    /**
     * Gets an appropriate <code>SimpleDateFormat</code> for given locale, 
     * default Date format pattern is not provided.
     */
    private SimpleDateFormat getFormatter(String pattern, Locale locale) {
        // This method is a fix for null pattern, which would cause 
        // Null pointer exception when applied
        // Note: that many constructors default the pattern to null, 
        // so it only makes sense to handle nulls gracefully
        if(pattern == null) {
            pattern = locPattern ? 
                new SimpleDateFormat().toLocalizedPattern() : new SimpleDateFormat().toPattern();
            log.warn("Null pattern was provided, defaulting to: " + pattern);
        }
        SimpleDateFormat format = new SimpleDateFormat(pattern, locale);
        format.setLenient(isLenient);
        return format;
    }
}