How to use the Locale function for internationalization in Java

In a modern, diversified society, users of a software program do not only come from a specific geographical area. Because of the need for internationalization, software programs need to be able to provide users in different regions or countries with their own languages ​​and formats to facilitate better use and improve user experience and user satisfaction. In the Java language, Locale is a powerful international class provided by Java. We can perform some multi-language operations based on the Locale class, especially formatting and parsing.

The Locale class can help us format date, time, currency values, numbers, strings and other text in Java programs, and customize the format conversion to comply with the language and cultural habits of a specific country or region. . The Locale class provides a simple, flexible and reusable way to implement the internationalization function of Java programs.

The Locale class supported by Java is related to the locale. Depending on the time zone and environment, Locale can convert general Java data types into relevant strings in the corresponding locale, or convert general strings into Java type of data. In Java, the most commonly used methods of Locale are getDisplayName(), getCountry(), getLanguage(), getDisplayCountry(), getDisplayLanguage(), etc. They all exist to obtain Locale information.

The following are some commonly used Locale methods:

1. Instancing Locale

Locale provides two construction methods, as follows:

Locale(String language)

Locale(String language, String country)

Where language represents the language code (ISO 639 alpha-2 or alpha-3), and country represents the country/region code (ISO 3166 alpha-2). The instantiation process is as follows:

Locale locale1 = new Locale("cn");
Locale locale2 = new Locale("en", "US");

2. Get Locale information

We can obtain Locale information through the methods provided by the Locale class. Commonly used methods are:

getCountry(): Get the country/region code (ISO 3166 alpha-2 ).

getLanguage(): Get the language code (ISO 639 alpha-2 or alpha-3).

getDisplayName(): Get the Locale name.

getDisplayCountry(): Get the country/region name.

getDisplayLanguage(): Get the language name.

Locale locale = Locale.getDefault();
String country = locale.getCountry();
String language = locale.getLanguage();

3. Formatting Output

The Locale class can also help us format data into a format that conforms to the current environment and output the character form in a specific locale. For data types such as time, date, amount, etc., you can use the NumberFormat and DateFormat classes for formatting. As follows:

NumberFormat nf = NumberFormat.getCurrencyInstance(locale);
double money = 100.54;
String str = nf.format(money); // The output result is: ￥100.54

DateFormat df = DateFormat.getDateInstance(DateFormat.LONG, locale);
Date date = new Date();
String dateStr = df.format(date); // The output result is: 2021 1 Month 1

4. Parse data

When we get text from user input, we may need to convert the data into a specific data type, such as a string Convert to date etc. The Locale class can help us automatically format text into a data structure under a specific protocol. As follows:

DateFormat df = DateFormat.getDateInstance(DateFormat.LONG, locale);
Date inputDate = df.parse("January 1, 2021");

NumberFormat nf = NumberFormat.getCurrencyInstance(locale);
double inputValue = nf.parse("￥100.54").doubleValue();

By using Locale, we can easily internationalize Java programs. Make the program more in line with the needs of users in different regions or countries, and improve user comfort and satisfaction.

The above is the detailed content of How to use the Locale function for internationalization in Java. For more information, please follow other related articles on the PHP Chinese website!