如何修复 FindBugs 的警告 "Use of non-localized String.toUpperCase() or String.toLowerCase()"?

How to fix FindBugs' warning "Use of non-localized String.toUpperCase() or String.toLowerCase()"?

我有以下代码:

/**
 * Performs the filename extension check (command-line argument validity).
 * @param valid True, if the check should be performed.
 * @param filename File name to test.
 * @return False, if the test was done and the filename does not end with
 *  ".xml". Value of valid otherwise.
 */
private boolean checkFileNameExtension(final boolean valid,
    final String filename) {
    boolean result = valid;
    if (valid
        && !filename.toLowerCase(Locale.ENGLISH).endsWith(".xml")) {
        this.logger.error("File doesn't have XML extension.");
        result = false;
    }
    return result;
}

FindBugs 抱怨 toLowerCase 调用:

[WARNING] FindBugs: L I Dm: Use of non-localized String.toUpperCase() or 
String.toLowerCase() in [...]checkFileNameExtension(boolean, String)

如果我能确定所有文件名的名称始终只有拉丁字母,我该如何正确修复该警告(正确的方法)?

添加 Locale.ENGLISH(或 Locale.ROOT)是修复错误的正确方法,因此如果添加后 FindBugs 仍然报告该错误,那么您可能在 FindBugs 中发现了错误本身。

像下面这样使用,警告就会消失。

import org.apache.commons.lang3.StringUtils;
filename = StringUtils.upperCase(filename);

我有同样的错误。试试这个:

yourString.toLowerCase(Locale.getDefault());