java中ResourceBundle的io查询

Question

直接从这个API：

Otherwise, getBundle attempts to locate a property resource file using the generated properties file name. It generates a path name from the candidate bundle name by replacing all "." characters with "/" and appending the string ".properties". It attempts to find a "resource" with this name using ClassLoader.getResource.

它们对replacing all "." characters with "/"意味着什么？举个例子吧？ 附言：我同意追加。属性

Answer 1

假设您有一个名为

com.yourgroup.bundles

包含名为

hello_en_US.properties

您必须指定以下任一项才能加载捆绑包

ResourceBundle bundle = ResourceBundle.getBundle("com.yourgroup.bundles.hello");
ResourceBundle bundle = ResourceBundle.getBundle("com/yourgroup/bundles/hello");

基本上，javadoc告诉您如何将传递给getBundle方法的参数转换为类路径上的资源。对我来说，默认的语言环境是en_US，所以

com.yourgroup.bundles.hello

转化为

com/yourgroup/bundles/hello_en_US.properties

然后，它可以使用ClassLoader来查找该资源

如果正确映射其名称，它返回的ResourceBundle实现实际上可能是一个自定义类。按照javadoc进行操作。否则，它只是一个Properties资源包

魔法发生在ResourceBundle#newBundle(...)

String bundleName = toBundleName(baseName, locale); // baseName being 'com.yourgroup.bundles.hello' in my example above
...
final String resourceName = toResourceName(bundleName, "properties");

这很简单

public final String toResourceName(String bundleName, String suffix) {
    StringBuilder sb = new StringBuilder(bundleName.length() + 1 + suffix.length());
    sb.append(bundleName.replace('.', '/')).append('.').append(suffix);
    return sb.toString();
}

....

URL url = classLoader.getResource(resourceName);
...
bundle = new PropertyResourceBundle(stream); // stream comes from url