java - 如何在 Java 中将下划线转换为人类可读的名称？

Question

我想编写一个将 CamelCase 转换为人类可读名称的方法。这与this question非常相似。但现在带有下划线。

这是测试用例:

public void testSplitUnderscore() {
    assertEquals("lowercase", splitUnderscore("lowercase"));
    assertEquals("Class", splitUnderscore("Class"));
    assertEquals("My Class", splitUnderscore("My_Class"));
    assertEquals("HTML", splitUnderscore("HTML"));
    assertEquals("PDF Loader", splitUnderscore("PDF_Loader"));
    assertEquals("A String", splitUnderscore("A_String"));
    assertEquals("Simple XML Parser", splitUnderscore("Simple_XML_Parser"));
    assertEquals("GL 11 Version", splitUnderscore("GL_11_Version"));
    assertEquals("99 Bottles", splitUnderscore("99_Bottle"));
    assertEquals("May 5", splitUnderscore("May_5"));
    assertEquals("BFG 9000", splitUnderscore("BFG_9000"));
    assertEquals("beginning", splitUnderscore("_beginning"));
    assertEquals("end", splitUnderscore("end_"));
    assertEquals("double middle", splitUnderscore("double__middle"));
    assertEquals("double end", splitUnderscore("double_end__"));
    assertEquals("double start", splitUnderscore("__double_start"));
    assertEquals("double start middle end", splitUnderscore("__double_start__middle_end__"));
}

Answer 1

实现此目的的一种简单方法是将每个 '_' 替换为 ' '，然后修剪掉最终字符串中的空格:

public static String splitUnderscore(String s) {
    return s.replace("_", " ").trim();
}

虽然上述方法适用于大多数情况，但为了处理多个相邻下划线，我们可以使用正则表达式将任意数量的连续下划线替换为单个 ' ':

public static String splitUnderscore(String s) {
    return s.replaceAll("_{1,}", " ").trim();
}