我们创建了一个资源。utf8文件，包含UTF-8格式的资源，并有一个规则运行如下:

native2ascii -encoding utf8 resources.utf8 resources.properties

package com.varaneckas.utils;  

import java.io.UnsupportedEncodingException;  
import java.util.Enumeration;  
import java.util.PropertyResourceBundle;  
import java.util.ResourceBundle;  

/** 
 * UTF-8 friendly ResourceBundle support 
 *  
 * Utility that allows having multi-byte characters inside java .property files. 
 * It removes the need for Sun's native2ascii application, you can simply have 
 * UTF-8 encoded editable .property files. 
 *  
 * Use:  
 * ResourceBundle bundle = Utf8ResourceBundle.getBundle("bundle_name"); 
 *  
 * @author Tomas Varaneckas <tomas.varaneckas@gmail.com> 
 */  
public abstract class Utf8ResourceBundle {  

    /** 
     * Gets the unicode friendly resource bundle 
     *  
     * @param baseName 
     * @see ResourceBundle#getBundle(String) 
     * @return Unicode friendly resource bundle 
     */  
    public static final ResourceBundle getBundle(final String baseName) {  
        return createUtf8PropertyResourceBundle(  
                ResourceBundle.getBundle(baseName));  
    }  

    /** 
     * Creates unicode friendly {@link PropertyResourceBundle} if possible. 
     *  
     * @param bundle  
     * @return Unicode friendly property resource bundle 
     */  
    private static ResourceBundle createUtf8PropertyResourceBundle(  
            final ResourceBundle bundle) {  
        if (!(bundle instanceof PropertyResourceBundle)) {  
            return bundle;  
        }  
        return new Utf8PropertyResourceBundle((PropertyResourceBundle) bundle);  
    }  

    /** 
     * Resource Bundle that does the hard work 
     */  
    private static class Utf8PropertyResourceBundle extends ResourceBundle {  

        /** 
         * Bundle with unicode data 
         */  
        private final PropertyResourceBundle bundle;  

        /** 
         * Initializing constructor 
         *  
         * @param bundle 
         */  
        private Utf8PropertyResourceBundle(final PropertyResourceBundle bundle) {  
            this.bundle = bundle;  
        }  

        @Override  
        @SuppressWarnings("unchecked")  
        public Enumeration getKeys() {  
            return bundle.getKeys();  
        }  

        @Override  
        protected Object handleGetObject(final String key) {  
            final String value = bundle.getString(key);  
            if (value == null)  
                return null;  
            try {  
                return new String(value.getBytes("ISO-8859-1"), "UTF-8");  
            } catch (final UnsupportedEncodingException e) {  
                throw new RuntimeException("Encoding not supported", e);  
            }  
        }  
    }  
}  

As one suggested, i went through implementation of resource bundle.. but that did not help.. as the bundle was always called under en_US locale... i tried to set my default locale to a different language and still my implementation of resource bundle control was being called with en_US... i tried to put log messages and do a step through debug and see if a different local call was being made after i change locale at run time through xhtml and JSF calls... that did not happend... then i tried to do a system set default to a utf8 for reading files by my server (tomcat server).. but that caused pronlem as all my class libraries were not compiled under utf8 and tomcat started to read then in utf8 format and server was not running properly... then i ended up with implementing a method in my java controller to be called from xhtml files.. in that method i did the following:

        public String message(String key, boolean toUTF8) throws Throwable{
            String result = "";
            try{
                FacesContext context = FacesContext.getCurrentInstance();
                String message = context.getApplication().getResourceBundle(context, "messages").getString(key);

                result = message==null ? "" : toUTF8 ? new String(message.getBytes("iso8859-1"), "utf-8") : message;
            }catch(Throwable t){}
            return result;
        }

我特别紧张，因为这可能会降低我应用程序的性能……然而，在实现这个之后，看起来好像我的应用程序现在更快了。我认为这是因为，我现在直接访问属性，而不是让JSF解析其访问属性的方式…我特别在这个调用中传递布尔参数，因为我知道一些属性不会被翻译，不需要在utf8格式…

现在我已经以UTF8格式保存了我的属性文件，它工作正常，因为我的应用程序中的每个用户都有一个引用的区域设置偏好。

我们创建了一个资源。utf8文件，包含UTF-8格式的资源，并有一个规则运行如下:

native2ascii -encoding utf8 resources.utf8 resources.properties

从Java 9开始，加载属性文件的默认值已更改为UTF-8。https://docs.oracle.com/javase/9/intl/internationalization-enhancements-jdk-9.htm

假设你有一个ResourceBundle实例，你可以通过以下方式获取String:

String val = bundle.getString(key); 

我解决了我的日语显示问题:

return new String(val.getBytes("ISO-8859-1"), "UTF-8");