Package org.codehaus.groovy.util

Class URLStreams

java.lang.Object

org.codehaus.groovy.util.URLStreams

public class URLStreams
extends Object

Utilities for opening URL connections and reading last-modified times with Groovy-specific defaults.

Caching is disabled so file: and jar: URLs do not pin a file handle. On Windows an open handle prevents the file from being deleted or replaced.

Method Summary

Modifier and Type	Method	Description
static long	getLastModified(URL url)	Last-modified time of url for source-freshness checks used by GroovyClassLoader and ClassNodeResolver.
static long	getUncachedLastModified(URL url)	Returns URLConnection.getLastModified() for url without caching the connection, then closes it.
static InputStream	openUncachedStream(URL url)	Opens an InputStream reading from the given URL without caching the connection.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

openUncachedStream

public static InputStream openUncachedStream(URL url)
                                      throws IOException

Opens an InputStream reading from the given URL without caching the connection. This prevents file descriptor leaks when reading from file-system URLs.

Parameters:

url - the URL to connect to

Returns:

an input stream reading from the URL connection

Throws:

IOException

getLastModified

public static long getLastModified(URL url)
                            throws IOException

Last-modified time of url for source-freshness checks used by GroovyClassLoader and ClassNodeResolver.

file: URLs use File.lastModified() because URLConnection.getLastModified() often reports -1. The path mapping includes the historical Windows form file://c|/... where | stood for :. Other protocols use getUncachedLastModified(URL).

Parameters:

url - the source URL

Returns:

the last-modified time in milliseconds since the epoch, or 0 if it is not known

Throws:

IOException - if a non-file: URL cannot be opened

getUncachedLastModified

public static long getUncachedLastModified(URL url)
                                    throws IOException

Returns URLConnection.getLastModified() for url without caching the connection, then closes it.

jar: URLs otherwise keep a cached JarFile open after URLConnection.getInputStream() is closed, which on Windows locks the JAR until the JVM exits. A failure to open the stream (missing JAR entry, unreachable URL) is propagated so callers can treat the source as unreadable; a failure to close after a successful open is ignored because last-modified was already obtained.

Parameters:

url - the URL whose last-modified time is required

Returns:

the last-modified time in milliseconds since the epoch, or 0 if it is not known

Throws:

IOException - if the connection or stream cannot be opened