Servlet – 国际化示例

默认情况下，网页以英语提供。它可以通过Java技术中的“国际化”概念以用户选择的语言提供。国际化（i18n）帮助用户根据他们的国籍或访问的位置查看页面。请求者的语言环境可以由 servlet 检索，具体取决于他们的国籍，它将返回 Locale 对象。

java.util.Locale request.getLocale() 

有不同的方法可用于检测语言环境

S.N	Method	Description
1	getCountry()	It helps to return “country/region” code in UPPER CASE for the locale in ISO 3166 2-letter format.
2	getDisplayCountry()	It helps to return a “NAME” for the locale’s country and it is appropriate for display to the user.
3	getLanguage()	It helps to return the “LANGUAGE CODE” in lower case for the locale in ISO 639 format.
4	getDisplayLanguage()	It helps to return a “NAME FOR LOCALE’s LANGUAGE” and it is appropriate for display to the user.
5.	getISO3Country()	It helps to return a three-letter abbreviation for the locale’s country.
6	getISO3Language()	It helps to return a three-letter abbreviation for the locale’s language.

例子

让我们看看不同的例子来显示请求的语言和相关国家

示例 1：

Java

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Locale;
 
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
// Servlet implementation class SearchServlet
@WebServlet("/getCurrentLocationInformation")
public class GetLocationServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
  
    public GetLocationServlet() {
        super();
    }
 
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
 
          // Get the  Locale information
          // by using java.util.Locale
          Locale locale = request.getLocale();
           
          // language
          String localeLanguage = locale.getLanguage();
           
          // country
          String localeCountry = locale.getCountry();
 
          // Print the  response content type
          // below by using PrintWriter object
          response.setContentType("text/html");
          PrintWriter printWriter = response.getWriter();
 
          String title = "Locale detection";
          String docType =
             "\n";
           
          printWriter.println(docType +
             "\n" +
                "\n" +
                "\n" +
                   "
 " + ""  + "Language : " + localeLanguage + "" + "
\n" +
                   "
" + "" + "Country    : " + localeCountry + "" + "
\n" +
             "" +
             ""
          );  
        
       }
    }

通过执行上面的代码，我们可以得到如下输出

输出：

默认语言设置

如果我们想将语言设置为不同的语言，可以通过语言设置来完成。

// In order to set spanish language code.
response.setHeader("Content-Language", "es");
// Similarly we can set different language codes in this way
// http://www.mathguide.de/info/tools/languagecode.html provides various language code

示例 2：

Java

protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
 
          // Print the  response content type below
          // by using PrintWriter object
          response.setContentType("text/html");
          PrintWriter printWriter = response.getWriter();   
          
          // Set spanish language code. In this place, we need
          // to provide the required language setting
          response.setHeader("Content-Language", "es");
          String title = "En Español";
          String docType =
          "\n";
           
          // As it is spanish, the messages
          // also given in spanish
          printWriter.println(docType +
             "\n" +
                "\n" +
                "\n" +
                   "
" + "" + "En Español:" + "" + "
\n" +
                   "
" + "" + "Bienvenido a GeeksForGeeks!" + "" + "
\n" +
                ""+
             "");
       }

输出：

设置为西班牙语

示例 3：

具体到 locale ，通过使用Java.text.DateFormat 类和 getDateTimeInstance() 方法，我们可以格式化日期和时间

Java

// import java.text.DateFormat as it is getting used
protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {       
          // Set response content type
          response.setContentType("text/html");
          PrintWriter printWriter = response.getWriter();
           
          // Get the client's Locale by using request.getLocale()
          Locale locale = request.getLocale( );
          String date = DateFormat.getDateTimeInstance(DateFormat.FULL,
             DateFormat.SHORT, locale).format(new Date( ));
          String title = "Displaying Locale Specific Dates";
          String docType =
             "\n";
          
          printWriter.println(docType +
             "\n" +
                "\n" +
                "\n" +
                   "
" + ""  + "Locale specific date : " + date + "" + "
\n" +
                "" +
             ""
          );
       }

输出：

显示地区日期

示例 4：

特定于 locale ，通过使用Java.txt.NumberFormat 类和 getCurrencyInstance() 方法，我们可以格式化货币

Java

// import java.text.NumberFormat; has to be imported
protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {       
          // Set response content type
          response.setContentType("text/html");
          PrintWriter printWriter = response.getWriter();  
           
          // Get the current Locale information
          Locale currentLocale = request.getLocale( );
          NumberFormat numberFormat = NumberFormat.getCurrencyInstance(currentLocale);
          String formattedCurrency = numberFormat.format(100000);
 
          String title = "Displaying Locale Specific Currency";
          String docType =
             "\n";
           
          printWriter.println(docType +
             "\n" +
                "\n" +
                "\n" +
                   "
" + ""  + "Currency : " +formattedCurrency + "" +"
\n" +
                ""+
             ""
          );
}

输出：

国际化的优势

• 占领国外市场更容易。
• 呈现与语言环境无关的结果
• 一开始，如果实施，软件在全球市场的扩展会更容易。

结论

任何旨在在全球市场上开发的软件，都只能以国际方式进行准备。在Java中，我们可以使用上述方法来实现国际化。