Effective Java说：
// Potential security hole!
static public final Thing[] VALUES = {…};
public static final array
声明static final公共字段标志着类常量，非常适合原始数据类型（int、double等）和不可变类。
对于数组，问题在于即使数组引用是常量，数组元素仍然是可变的；由于它是一个字段，不受更改保护、不可控，所以不常用。
为了解决这个问题，可以将数组字段限制为私有/包私有，这样可以缩小可疑代码的范围。通常，更好的做法是取消数组使用List或者集合类型。通过集合，只有通过方法才能更新字段，因此变化可控。
考虑下面的例子：
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public class SafeSites {
// a trusted class with permission to create network connections
public static final String[] ALLOWED_URLS = new String[] {
"http://amazon.com", "http://cnn.com"};
// this method allows untrusted code to connect to allowed sites (only)
public static void doRequest(String url) {
for (String allowed : ALLOWED_URLS) {
if (url.equals(allowed)) {
// send a request ...
}
}
}
}
public class Untrusted {
// An untrusted class that is executed in a security sandbox.
public void naughtyBoy() {
SafeSites.ALLOWED_URLS[0] = "http://myporn.com";
SafeSites.doRequest("http://myporn.com");
}
}
Note that a nonzero-length array is always mutable, so it is wrong for a class to have a public static final array field, or an accessor that returns such a field. If a class has such a field or accessor, clients will be able to modify the contents of the array.
– Effective Java, 2nd Ed. (page 70)