Question

我在使用Python确定有效的Java包名称时遇到问题。这是代码：

    packageName = "com.domain.lala" # valid, not rejected -> correct
    #packageName = ".com.domain.lala" # invalid, rejected -> correct
    #packageName = "com..domain.lala" # invalid, not rejected -> incorrect
    #packageName = "com.domain.lala." # invalid, not rejected -> incorrect

    matchObject = re.match("([a-z_]{1}[a-z0-9_]*(\.[a-z_]{1}[a-z0-9_]*)*)",
                           packageName)

    if matchObject is not None:
        print packageName + " is a package name!"
    else:
        print packageName + " is *not* a package name!"
        Utilities.show_error("Invalid Package Name", "Invalid package name " + packageName + "!", "Ok", "", "")

包名称必须以小写字母或下划线开头，每个点后面必须至少再跟一个小写字母或下划线。所有其他字符可以是小写字母，数字或下划线。不允许运行任何点，它可能不会以点结束或以点开头。

我该如何解决这个问题？

Answer 1

在正则表达式的末尾添加$以强制匹配完整字符串。现在它只匹配一个部分字符串，所以它错误地接受了最后添加了垃圾的有效包名。

Answer 2

大写字母实际上在Java包名称中是允许的。他们只是气馁，但它确实有效。

正则表达式应该是：

^([a-zA-Z_]{1}[a-zA-Z0-9_]*(\\.[a-zA-Z_]{1}[a-zA-Z0-9_]*)*)?$

Answer 3

您需要设置行的开头和行尾标记。所以正则表达式看起来应该像 -

^([a-z_]{1}[a-z0-9_]*(\.[a-z_]{1}[a-z0-9_]*)*)$

Answer 4

以下模式对我有用：

/^[a-z][a-z0-9_]*(\.[a-z0-9_]+)+[0-9a-z_]$/i;

结果可在此gist中找到。

[✔] me.unfollowers.droid
[✔] me_.unfollowers.droid
[✔] me._unfollowers.droid
[✔] me.unfo11llowers.droid
[✔] me11.unfollowers.droid
[✔] m11e.unfollowers.droid
[✗] 1me.unfollowers.droid
[✔] me.unfollowers23.droid
[✔] me.unfollowers.droid23d
[✔] me.unfollowers_.droid
[✔] me.unfollowers._droid
[✔] me.unfollowers_._droid
[✔] me.unfollowers.droid_
[✔] me.unfollowers.droid32
[✗] me.unfollowers.droid/
[✗] me:.unfollowers.droid
[✗] :me.unfollowers.droid
[✗] me.unfollowers.dro;id
[✗] me.unfollowe^rs.droid
[✗] me.unfollowers.droid.
[✗] me.unfollowers..droid
[✗] me.unfollowers.droid._
[✔] me.unfollowers.11212
[✔] me.1.unfollowers.11212
[✗] me..unfollowers.11212
[✗] abc
[✗] abc.
[✗] .abc

Answer 5

您可以改为解析字符串：

def valid_java_package_name(string):
    tree = string.split('.')

    if len(tree) == 0:
        return false

    for node in tree:
        if not valid_java_package_node(node):
            return false

    return true

用于Java包名称的Python正则表达式

5 个答案: