Java中的 Locale.Builder setLanguageTag() 方法及示例

Java中Java .util.Locale.Builder 类的setLanguageTag(String)方法用于将此 Locale.Builder 重置为指定的 IETF BCP 47 语言标记。这意味着此方法将重置 Locale.Builder 实例的当前状态以匹配提供的语言标签并返回它。

句法：

public Locale.Builder setLanguageTag(String languageTag)

参数：此方法接受languageTag作为参数，该参数是要设置为此 Locale.Builder 实例的字符串。

返回值：此方法返回一个Locale.Builder 实例，该实例是此 Locale.Builder 设置为指定语言标记的状态。

异常：此方法抛出以下异常：

• IllformedLocaleException : 如果指定的 languageTag 有任何格式错误的字段

方案一：

// Java program to demonstrate
// the above method
  
import java.util.*;
import java.util.Locale.*;
  
public class LocaleBuilderDemo {
    public static void main(String[] args)
    {
  
        // Creating a new Locale.Builder
        Locale.Builder localeBuilder
            = new Builder();
  
        // Displaying Locale.Builder
        System.out.println("LocaleBuilder: "
                           + localeBuilder);
  
        // setting the languageTag
        // of Locale.Builder
        String languageTag = "FRENCH";
        System.out.println("Setting the language: "
                           + languageTag);
  
        localeBuilder
            = localeBuilder
                  .setLanguageTag(languageTag);
  
        // Displaying Locale.Builder
        System.out.println("Updated LocaleBuilder: "
                           + localeBuilder);
    }
}

输出：

LocaleBuilder: java.util.Locale$Builder@232204a1
Setting the language: FRENCH
Updated LocaleBuilder: java.util.Locale$Builder@232204a1

方案二：

// Java program to demonstrate
// the above method
  
import java.util.*;
import java.util.Locale.*;
  
public class LocaleBuilderDemo {
    public static void main(String[] args)
    {
  
        // Creating a new Locale.Builder
        Locale.Builder localeBuilder
            = new Builder();
  
        // Displaying Locale.Builder
        System.out.println("LocaleBuilder: "
                           + localeBuilder);
  
        // setting the languageTag
        // of Locale.Builder
        String languageTag = "asdasf@!vsd#";
        System.out.println("Setting the languageTag: "
                           + languageTag);
  
        try {
            localeBuilder
                = localeBuilder
                      .setLanguageTag(languageTag);
  
            // Displaying Locale.Builder
            System.out.println("Updated LocaleBuilder: "
                               + localeBuilder);
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

输出：

LocaleBuilder: java.util.Locale$Builder@232204a1
Setting the languageTag: asdasf@!vsd#
java.util.IllformedLocaleException: Invalid subtag: asdasf@!vsd# [at index 0]

参考： https://docs.oracle.com/javase/9/docs/api/ Java/util/Locale.Builder.html#setLanguageTag-java.lang.String-