Update `Path` creation for nested locations to allow both UNC and classic
file references to be used. This commit attempts to align our URL
handling with that of standard file URLs. The `NestedLocation` class
no longer attempts to remove leading all `\` characters and instead
only removes the first `\` when the second char is `:`. This duplicates
the logic found in Java's own internal `WindowsUriSupport` class which
is used when calling `Path.of(url)` with a `file:` URL.
Fixes gh-40549
Fix regression in `JarUrlConnection` where a NullPointerException could
be thrown internally causing performance issues.
When the SecurityManager is present, the following stack trace is
thrown:
java.lang.NullPointerException: Cannot invoke "java.net.URLConnection.getPermission()" because "this.jarFileConnection" is null
at org.springframework.boot.loader.net.protocol.jar.JarUrlConnection.getPermission(JarUrlConnection.java:175)
at java.base/jdk.internal.loader.URLClassPath.check(URLClassPath.java:553)
at java.base/jdk.internal.loader.URLClassPath$Loader.findResource(URLClassPath.java:612)
at java.base/jdk.internal.loader.URLClassPath.findResource(URLClassPath.java:296)
at java.base/java.net.URLClassLoader$2.run(URLClassLoader.java:629)
at java.base/java.net.URLClassLoader$2.run(URLClassLoader.java:627)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
at java.base/java.net.URLClassLoader.findResource(URLClassLoader.java:626)
at org.springframework.boot.loader.net.protocol.jar.JarUrlClassLoader.findResource(JarUrlClassLoader.java:70)
at java.base/java.lang.ClassLoader.getResource(ClassLoader.java:1403)
at java.base/java.net.URLClassLoader.getResourceAsStream(URLClassLoader.java:290)
at java.base/java.lang.Class.getResourceAsStream(Class.java:2850)
See gh-39856
Refine the fix for gh-38611 so that `ClosedByInterruptException` no
longer retries in a loop.
Our previous fix was flawed due to the fact that another interrupt
could occur after we clear the first and whilst we are reading data.
If this happens 10 times in a row, we raise an exception and end up
causing NoClassDefFoundError errors.
Our new approach retains the use of `FileChannel` and a direct buffer
up to the point that a `ClosedByInterruptException` is raised or the
thread is detected as interrupted. At that point, we temporarily
switch to using a `RandomAccessFile` to access the data. This will
block the thread until the data has been read.
Fixes gh-40096
Rename the internal `FileChannelDataBlock` to `FileDataBlock` since we
want to fallback to a `RandomAccessFile` when a thread is interrupted.
See gh-40096
