如何独立分割路径平台？

I'm using the following code to get an array with all sub directories from a given path.

我正在使用以下代码来获取包含给定路径中所有子目录的数组。

String[] subDirs = path.split(File.separator); 

I need the array to check if certain folders are at the right place in this path. This looked like a good solution until findBugs complains that File.separator is used as a regular expression. It seems that passing the windows file separator to a function that is building a regex from it is a bad idea because the backslash being an escape character.

我需要数组来检查某些文件夹是否在此路径中的正确位置。这看起来是一个很好的解决方案，直到findBugs抱怨File.separator用作正则表达式。似乎将Windows文件分隔符传递给正在构建正则表达式的函数是一个坏主意，因为反斜杠是一个转义字符。

How can I split the path in a cross platform way without using File.separator? Or is code like this okay?

如何在不使用File.separator的情况下以跨平台方式拆分路径？或者这样的代码好吗？

String[] subDirs = path.split("/"); 

6 个解决方案

#1

Use path.getParentFile() repeatedly to get all components of a path.

重复使用path.getParentFile（）获取路径的所有组件。

Discouraged way would be to path.replaceAll("\\", "/").split("/").

气馁的方式是path.replaceAll（“\\”，“/”）。split（“/”）。

#2

Literalizing pattern strings

Whenever you need to literalize an arbitraryString to be used as a regex pattern, use Pattern.quote:

每当您需要将任意字符串文字化以用作正则表达式模式时，请使用Pattern.quote：

From the API:

来自API：

public static String quote(String s)

public static String quote（String s）

Returns a literal pattern String for the specified String. This method produces a String that can be used to create a Pattern that would match the string s as if it were a literal pattern. Metacharacters or escape sequences in the input sequence will be given no special meaning.

返回指定String的文字模式String。此方法生成一个String，该String可用于创建与字符串s匹配的Pattern，就好像它是文字模式一样。输入序列中的元字符或转义序列将没有特殊含义。

Parameters: s - The string to be literalized
Returns: A literal string replacement

参数：s - 要文字化的字符串返回：文字字符串替换

This means that you can do the following:

这意味着您可以执行以下操作：

String[] subDirs = path.split(Pattern.quote(File.separator));

---

Literalizing replacement strings

If you need to literalize an arbitrary replacement String, use Matcher.quoteReplacement.

如果需要对任意替换String进行字面化，请使用Matcher.quoteReplacement。

From the API:

来自API：

public static String quoteReplacement(String s)

public static String quoteReplacement（String s）

Returns a literal replacement String for the specified String. This method produces a String that will work as a literal replacement s in the appendReplacement method of the Matcher class. The String produced will match the sequence of characters in s treated as a literal sequence. Slashes ('\') and dollar signs ('$') will be given no special meaning.

返回指定String的文字替换String。此方法生成一个String，它将作为Matcher类的appendReplacement方法中的文字替换。生成的String将匹配s中作为文字序列处理的字符序列。斜杠（'\'）和美元符号（'$'）将没有特殊含义。

Parameters: s - The string to be literalized
Returns: A literal string replacement

参数：s - 要文字化的字符串返回：文字字符串替换

This quoted replacement String is also useful in String.replaceFirst and String.replaceAll:

这个引用的替换String在String.replaceFirst和String.replaceAll中也很有用：

Note that backslashes (\) and dollar signs ($) in the replacement string may cause the results to be different than if it were being treated as a literal replacement string. Use Matcher.quoteReplacement to suppress the special meaning of these characters, if desired.

请注意，替换字符串中的反斜杠（\）和美元符号（$）可能会导致结果与将其视为文字替换字符串时的结果不同。如果需要，使用Matcher.quoteReplacement来抑制这些字符的特殊含义。

---

Examples

    System.out.println(
        "O.M.G.".replaceAll(".", "!")
    ); // prints "!!!!!!"

    System.out.println(
        "O.M.G.".replaceAll(Pattern.quote("."), "!")
    ); // prints "O!M!G!"

    System.out.println(
        "Microsoft software".replaceAll("so", "$0")
    ); // prints "Microsoft software"

    System.out.println(
        "Microsoft software".replaceAll("so", Matcher.quoteReplacement("$0"))
    ); // prints "Micro$0ft $0ftware"

#3

java.nio.file.Path implements Iterable<Path>, so you can do:

java.nio.file.Path实现了Iterable ，所以你可以这样做：

public static void showElements(Path p) {
    List<String> nameElements = new ArrayList<>();
    for (Path nameElement: p)
        nameElements.add(nameElement.toFile().getName());
    System.out.printf("For this file: [%s], the following elements were found: [%s]\n"
                      , p.toAbsolutePath()
                      , Joiner.on(", ").join(nameElements));
}

Methods getNameCount and getName can be used for a similar purpose.

方法getNameCount和getName可用于类似目的。

#4

You can use Path interface:

您可以使用Path接口：

Path p = Paths.get(pathStr);
for (int i = 0; i < p.getNameCount(); i++) {
    String name = p.getName(i).toString();
    //do what you need with name;
}

#5

Create an empty list and use forEach to iterate over the path elements inserting each one into the list for later use:

创建一个空列表并使用forEach迭代路径元素，将每个元素插入列表*以后使用：

List<String> pathElements = new ArrayList<>();
Paths.get("/foo/bar/blah/baz").forEach(p -> pathElements.add(p.toString()))

Also, if you need a specific path element use:

此外，如果您需要特定的路径元素，请使用：

<pathObject>.getName(<intIndex>).toString() 

where <pathObject> is returned by a call to Paths.get(), and if you need multiple parts of the path returned in a string use:

其中 是通过调用Paths.get（）返回的，如果需要在字符串中返回路径的多个部分，请使用：

<pathObject>.subPath(<intStart>, <intEnd>).toString()

You can get the total number of path elements (for use in <intEnd>) with:

您可以使用以下命令获取路径元素的总数（在 中使用）：

<pathObject>.getNameCount()

There are other useful methods at the Java Path and Paths doc pages.

Java Path和Paths文档页面还有其他有用的方法。

#6

What about

关于什么

String[] subDirs = path.split(File.separator.replaceAll("\\", "\\\\"));