如何在Java中将Integer转换为本地化月份名称？

Question

我得到一个整数,我需要在各种语言环境中转换为月份名称:

locale en-us的示例:
1 - > 1月
2日 - > 2月

locale es-mx的示例:
1 - > Enero
2 - > Febrero

Answer 1

import java.text.DateFormatSymbols;
public String getMonth(int month) {
    return new DateFormatSymbols().getMonths()[month-1];
}

Answer 2

您需要将LLLL用于独立月份名称.这在文档中有SimpleDateFormat记录,例如:

SimpleDateFormat dateFormat = new SimpleDateFormat( "LLLL", Locale.getDefault() );
dateFormat.format( date );

Answer 3

java.time

从Java 1.8(或带有ThreeTen-Backport的 1.7和1.6 )开始,您可以使用:

Month                             // Enum class, predefining and naming a dozen objects, one for each month of the year. 
.of( 12 )                         // Retrieving one of the enum objects by number, 1-12. 
.getDisplayName(
    TextStyle.FULL_STANDALONE , 
    Locale.CANADA_FRENCH          // Locale determines the human language and cultural norms used in localizing. 
)

请注意,它integerMonth是从1开始的,即1表示1月份.1月至12月的范围始终为1至12(仅限公历).

Answer 4

我会使用SimpleDateFormat.有人纠正我,如果有一个更简单的方法来制作一个蒙太奇的日历,我现在在代码中这样做,我不太确定.

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.GregorianCalendar;


public String formatMonth(int month, Locale locale) {
    DateFormat formatter = new SimpleDateFormat("MMMM", locale);
    GregorianCalendar calendar = new GregorianCalendar();
    calendar.set(Calendar.DAY_OF_MONTH, 1);
    calendar.set(Calendar.MONTH, month-1);
    return formatter.format(calendar.getTime());
}

Answer 5

我就是这样做的.我会把范围检查留给int month你.

import java.text.DateFormatSymbols;

public String formatMonth(int month, Locale locale) {
    DateFormatSymbols symbols = new DateFormatSymbols(locale);
    String[] monthNames = symbols.getMonths();
    return monthNames[month - 1];
}

Answer 6

使用SimpleDateFormat.

import java.text.SimpleDateFormat;

public String formatMonth(String month) {
    SimpleDateFormat monthParse = new SimpleDateFormat("MM");
    SimpleDateFormat monthDisplay = new SimpleDateFormat("MMMM");
    return monthDisplay.format(monthParse.parse(month));
}


formatMonth("2"); 

结果:二月

Answer 7

显然在Android 2.2中有一个SimpleDateFormat的错误.

要使用月份名称,您必须自己在资源中定义它们:

<string-array name="month_names">
    <item>January</item>
    <item>February</item>
    <item>March</item>
    <item>April</item>
    <item>May</item>
    <item>June</item>
    <item>July</item>
    <item>August</item>
    <item>September</item>
    <item>October</item>
    <item>November</item>
    <item>December</item>
</string-array>

然后在你的代码中使用它们,如下所示:

/**
 * Get the month name of a Date. e.g. January for the Date 2011-01-01
 * 
 * @param date
 * @return e.g. "January"
 */
public static String getMonthName(Context context, Date date) {

    /*
     * Android 2.2 has a bug in SimpleDateFormat. Can't use "MMMM" for
     * getting the Month name for the given Locale. Thus relying on own
     * values from string resources
     */

    String result = "";

    Calendar cal = Calendar.getInstance();
    cal.setTime(date);
    int month = cal.get(Calendar.MONTH);

    try {
        result = context.getResources().getStringArray(R.array.month_names)[month];
    } catch (ArrayIndexOutOfBoundsException e) {
        result = Integer.toString(month);
    }

    return result;
}

Answer 8

TL;博士

Month.of( yourMonthNumber )           // Represent a month by its number, 1-12 for January-December. 
  .getDisplayName(                    // Generate text of the name of the month automatically localized. 
      TextStyle.SHORT_STANDALONE ,    // Specify how long or abbreviated the name of month should be.
      new Locale( "es" , "MX" )       // Locale determines (a) the human language used in translation, and (b) the cultural norms used in deciding issues of abbreviation, capitalization, punctuation, and so on.
  )                                   // Returns a String.

java.time.Month

现在在java.time类中更容易实现,这些类取代了这些麻烦的旧遗留日期时间类.

该Month枚举定义了十几个对象,每月一.

1月至12月的月份编号为1-12.

Month month = Month.of( 2 );  // 2 ? February.

让对象生成一个月份名称的 String ,自动本地化.

调整TextStyle以指定您想要名称的长度或缩写.请注意,在某些语言(非英语)中,月份名称会有所不同,如果单独使用或作为完整日期的一部分使用.所以每种文本样式都有一个…_STANDALONE变体.

指定a Locale以确定:

• 在翻译中应该使用哪种人类语言.
• 哪些文化规范应该决定诸如缩写,标点符号和大写的问题.

例:

Locale l = new Locale( "es" , "MX" );
String output = Month.FEBRUARY.getDisplayName( TextStyle.SHORT_STANDALONE , l );  // Or Locale.US, Locale.CANADA_FRENCH. 

名称→ Month对象

仅供参考,向另一个方向(解析月份名称字符串以获取Month枚举对象)不是内置的.您可以编写自己的类来执行此操作.以下是我对这类课程的快速尝试.使用风险由您自己承担.我没有认真考虑这个代码,也没有任何严肃的测试.

用法.

Month m = MonthDelocalizer.of( Locale.CANADA_FRENCH ).parse( "janvier" ) ;  // Month.JANUARY

码.

package com.basilbourque.example;

import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.time.Month;
import java.time.format.TextStyle;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

// For a given name of month in some language, determine the matching `java.time.Month` enum object.
// This class is the opposite of `Month.getDisplayName` which generates a localized string for a given `Month` object.
// Usage… MonthDelocalizer.of( Locale.CANADA_FRENCH ).parse( "janvier" ) ? Month.JANUARY
// Assumes `FormatStyle.FULL`, for names without abbreviation.
// About `java.time.Month` enum: https://docs.oracle.com/javase/9/docs/api/java/time/Month.html
// USE AT YOUR OWN RISK. Provided without guarantee or warranty. No serious testing or code review was performed.
public class MonthDelocalizer
{
    @NotNull
    private Locale locale;

    @NotNull
    private List < String > monthNames, monthNamesStandalone; // Some languages use an alternate spelling for a “standalone” month name used without the context of a date.

    // Constructor. Private, for static factory method.
    private MonthDelocalizer ( @NotNull Locale locale )
    {
        this.locale = locale;

        // Populate the pair of arrays, each having the translated month names.
        int countMonthsInYear = 12; // Twelve months in the year.
        this.monthNames = new ArrayList <>( countMonthsInYear );
        this.monthNamesStandalone = new ArrayList <>( countMonthsInYear );

        for ( int i = 1 ; i <= countMonthsInYear ; i++ )
        {
            this.monthNames.add( Month.of( i ).getDisplayName( TextStyle.FULL , this.locale ) );
            this.monthNamesStandalone.add( Month.of( i ).getDisplayName( TextStyle.FULL_STANDALONE , this.locale ) );
        }
//        System.out.println( this.monthNames );
//        System.out.println( this.monthNamesStandalone );
    }

    // Constructor. Private, for static factory method.
    // Personally, I think it unwise to default implicitly to a `Locale`. But I included this in case you disagree with me, and to follow the lead of the *java.time* classes. --Basil Bourque
    private MonthDelocalizer ( )
    {
        this( Locale.getDefault() );
    }

    // static factory method, instead of  constructors.
    // See article by Dr. Joshua Bloch. http://www.informit.com/articles/article.aspx?p=1216151
    // The `Locale` argument determines the human language and cultural norms used in de-localizing input strings.
    synchronized static public MonthDelocalizer of ( @NotNull Locale localeArg )
    {
        MonthDelocalizer x = new MonthDelocalizer( localeArg ); // This class could be optimized by caching this object.
        return x;
    }

    // Attempt to translate the name of a month to look-up a matching `Month` enum object.
    // Returns NULL if the passed String value is not found to be a valid name of month for the human language and cultural norms of the `Locale` specified when constructing this parent object, `MonthDelocalizer`.
    @Nullable
    public Month parse ( @NotNull String input )
    {
        int index = this.monthNames.indexOf( input );
        if ( - 1 == index )
        { // If no hit in the contextual names, try the standalone names.
            index = this.monthNamesStandalone.indexOf( input );
        }
        int ordinal = ( index + 1 );
        Month m = ( ordinal > 0 ) ? Month.of( ordinal ) : null;  // If we have a hit, determine the `Month` enum object. Else return null.
        if ( null == m )
        {
            throw new java.lang.IllegalArgumentException( "The passed month name: ‘" + input + "’ is not valid for locale: " + this.locale.toString() );
        }
        return m;
    }

    // `Object` class overrides.

    @Override
    public boolean equals ( Object o )
    {
        if ( this == o ) return true;
        if ( o == null || getClass() != o.getClass() ) return false;

        MonthDelocalizer that = ( MonthDelocalizer ) o;

        return locale.equals( that.locale );
    }

    @Override
    public int hashCode ( )
    {
        return locale.hashCode();
    }

    public static void main ( String[] args )
    {
        // Usage example:
        MonthDelocalizer monthDelocJapan = MonthDelocalizer.of( Locale.JAPAN );
        try
        {
            Month m = monthDelocJapan.parse( "pink elephant" ); // Invalid input.
        } catch ( IllegalArgumentException e )
        {
            // … handle error
            System.out.println( "ERROR: " + e.getLocalizedMessage() );
        }

        // Ignore exception. (not recommended)
        if ( MonthDelocalizer.of( Locale.CANADA_FRENCH ).parse( "janvier" ).equals( Month.JANUARY ) )
        {
            System.out.println( "GOOD - In locale "+Locale.CANADA_FRENCH+", the input ‘janvier’ parses to Month.JANUARY." );
        }
    }
}

关于java.time

该java.time框架是建立在Java 8和更高版本.这些类取代麻烦的老传统日期时间类,如java.util.Date,Calendar,和SimpleDateFormat.

现在处于维护模式的Joda-Time项目建议迁移到java.time类.

要了解更多信息,请参阅Oracle教程.并搜索Stack Overflow以获取许多示例和解释.规范是JSR 310.

您可以直接与数据库交换java.time对象.使用符合JDBC 4.2或更高版本的JDBC驱动程序.不需要字符串,不需要课程.java.sql.*

从哪里获取java.time类？

• Java SE 8, Java SE 9及更高版本
  • 内置.
  • 带有捆绑实现的标准Java API的一部分.
  • Java 9增加了一些小功能和修复.
• Java SE 6和 Java SE 7
  • 许多java.time功能都被反向移植到ThreeTen-Backport中的 Java 6和7 .
• Android的
  • 更高版本的Android捆绑java.time类的实现.
  • 对于早期的Android(<26),ThreeTenABP项目采用ThreeTen-Backport(如上所述).请参阅如何使用ThreeTenABP ....

该ThreeTen-额外项目与其他类扩展java.time.该项目是未来可能添加到java.time的试验场.您可以在此比如找到一些有用的类Interval,YearWeek,YearQuarter,和更多.