当resource bundle 的多语言文件里包含引号'时

时间:2022-11-23 07:18:44

背景

项目中使用Spring的ReloadableResourceBundleMessageSource这个类来实现多语言,有一次字符串里包含引号'时,解析时出了问题,一起来看一下吧

例子

resources下包含三个语言文件
当resource bundle 的多语言文件里包含引号'时

分别是:
bundle_zh_CN.properties
hello=你好吗?{0}

bundle_zh_TW.properties
hello=你好嗎?{0}

bundle_en.properties
hello=how are you ? {0}
测试类:
public class Main {
    public static void main(String[] args) throws UnsupportedEncodingException {
        System.out.println(getMessage("hello", new Object[] {"辉"}, Locale.CHINA));
        System.out.println(getMessage("hello", new Object[] {"輝"}, Locale.TRADITIONAL_CHINESE));
        System.out.println(getMessage("hello", new Object[] {"hui"}, Locale.ENGLISH));
    }

    public static String getMessage(String code, Object[] args, Locale locale) {
        ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
        messageSource.setDefaultEncoding(StandardCharsets.UTF_8.name());
        messageSource.setBasename("bundle");
        messageSource.setCacheSeconds(1800);
        return messageSource.getMessage(code, args, locale);
    }
}

输出:
你好吗?辉
你好嗎?輝
how are you ? hui

可以看出没什么问题

如果含有引号'

改成:
bundle_zh_CN.properties
hello=你好'吗?{0}

bundle_zh_TW.properties
hello=你好'嗎?{0}

bundle_en.properties
hello=how are' you ? {0}
输出结果:
你好吗?{0}
你好嗎?{0}
how are you ? {0}

可以看出如果含有引号',参数不起作用,而且引号'也没显示出来

原因

MessageFormat messageFormat = resolveCode(code, locale);
if (messageFormat != null) {
	synchronized (messageFormat) {
		return messageFormat.format(argsToUse);
	}
}

追踪源码,底层是由Java底层的MessageFormat来实现的

API中解释如下:
Within a String, a pair of single quotes can be used to quote any arbitrary characters except single quotes. 
For example, pattern string "'{0}'" represents string "{0}", not a FormatElement. 
A single quote itself must be represented by doubled single quotes '' throughout a String. 
For example, pattern string "'{''}'" is interpreted as a sequence of '{ (start of quoting and a left curly brace), '' (a single quote), and }' (a right curly brace and end of quoting), not '{' and '}' (quoted left and right curly braces): representing string "{'}", not "{}".

Any unmatched quote is treated as closed at the end of the given pattern. For example, pattern string "'{0}" is treated as pattern "'{0}'".

大概意思就是:
- 两个单引号里面的值保持不变,不会被格式化
- 如果想输出单引号,使用两个单引号'' 来输出单引号'
- 如果只有一个单引号,那么单引号后面的值就原封不动的输出来,即不会被格式化

修改

改成:
bundle_zh_CN.properties
hello=你好''吗?{0}

bundle_zh_TW.properties
hello=你好''嗎?{0}

bundle_en.properties
hello=how are'' you ? {0}

输出结果:
你好'吗?辉
你好'嗎?輝
how are' you ? hui
还有一点需要注意的就是:在没有参数的情况下,如果想输出引号,那就用一个引号即可,如下:
bundle_zh_CN.properties
hello=你好'吗?

bundle_zh_TW.properties
hello=你好'嗎?

bundle_en.properties
hello=how are' you ?
public static void main(String[] args) throws UnsupportedEncodingException {
    System.out.println(getMessage("hello", null, Locale.CHINA));
    System.out.println(getMessage("hello", null, Locale.TRADITIONAL_CHINESE));
    System.out.println(getMessage("hello", null, Locale.ENGLISH));
}

输出:
你好'吗?
你好'嗎?
how are' you ?