Class Resource

java.lang.Object
io.github.classgraph.Resource
All Implemented Interfaces:
Closeable, AutoCloseable, Comparable<Resource>
public abstract class Resource extends Object implements Closeable, Comparable<Resource>
A classpath or module path resource (i.e. file) that was found in an accepted/non-rejected package inside a classpath element or module.

  • Field Details

    • classpathElement

      private final ClasspathElement classpathElement
      The classpath element this resource was obtained from.

    • inputStream

      protected InputStream inputStream
      The input stream, or null.

    • byteBuffer

      protected ByteBuffer byteBuffer
      The byte buffer, or null.

    • length

      protected long length
      The length, or -1L for unknown.

    • toString

      private String toString
      The cached result of toString().

    • scanLog

      LogNode scanLog
      The LogNode used to log that the resource was found when classpath element paths are scanned. In the case of accepted classfile resources, sublog entries are added when the classfile's contents are scanned.

  • Constructor Details

    • Resource

      public Resource(ClasspathElement classpathElement, long length)
      Constructor.
      Parameters:
      classpathElement - the classpath element this resource was obtained from.
      length - the length the length of the resource.

  • Method Details

    • uriToURL

      private static URL uriToURL(URI uri)
      Convert a URI to URL, catching "jrt:" URIs as invalid.
      Parameters:
      uri - the uri
      Returns:
      the URL.
      Throws:
      IllegalArgumentException - if the URI could not be converted to a URL, or the URI had "jrt:" scheme.

    • getURI

      public URI getURI()
      Get the URI representing the resource's location.
      Returns:
      A URI representing the resource's location.
      Throws:
      IllegalArgumentException - the resource was obtained from a module and the module's location URI is null.

    • getURL

      public URL getURL()
      Get the URL representing the resource's location. Use getURI() instead if the resource may have come from a system module, or if this is a jlink'd runtime image, since "jrt:" URI schemes used by system modules and jlink'd runtime images are not supported by URL, and this will cause IllegalArgumentException to be thrown.
      Returns:
      A URL representing the resource's location.
      Throws:
      IllegalArgumentException - if the resource was obtained from a system module or jlink'd runtime image with a "jrt:" location URI, or the resource was obtained from a module and the module's location URI is null

    • getClasspathElementURI

      public URI getClasspathElementURI()
      Get the URI of the classpath element or module that this resource was obtained from.
      Returns:
      The URL of the classpath element or module that this resource was found within.
      Throws:
      IllegalArgumentException - if the classpath element does not have a valid URI (e.g. for modules whose location URI is null).

    • getClasspathElementURL

      public URL getClasspathElementURL()
      Get the URL of the classpath element or module that this resource was obtained from. Use getClasspathElementURI() instead if the resource may have come from a system module, or if this is a jlink'd runtime image, since "jrt:" URI schemes used by system modules and jlink'd runtime images are not supported by URL, and this will cause IllegalArgumentException to be thrown.
      Returns:
      The URL of the classpath element or module that this resource was found within.
      Throws:
      IllegalArgumentException - if the resource was obtained from a system module or jlink'd runtime image with a "jrt:" location URI, or the resource was obtained from a module and the module's location URI is null.

    • getClasspathElementFile

      public File getClasspathElementFile()
      Get the classpath element File.
      Returns:
      The File for the classpath element package root dir or jar that this Resource was found within, or null if this Resource was found in a module backed by a "jrt:" URI, or a module with an unknown location. May also return null if the classpath element was an http/https URL, and the jar was downloaded directly to RAM, rather than to a temp file on disk (e.g. if the temp dir is not writeable).

    • getModuleRef

      public ModuleRef getModuleRef()
      Get the The ModuleRef for the module that this Resource was found within.
      Returns:
      The ModuleRef for the module that this Resource was found within, as a ModuleRef, or null if this Resource was found in a directory or jar in the classpath.

    • getContentAsString

      public String getContentAsString() throws IOException
      Convenience method to get the content of this Resource as a String. Assumes UTF8 encoding. (Calls close() after completion.)
      Returns:
      the content of this Resource as a String.
      Throws:
      IOException - If an I/O exception occurred.

    • getPath

      public abstract String getPath()
      Get the path of this classpath resource relative to the package root.
      Returns:
      the path of this classpath resource relative to the package root. For example, for a resource path of "BOOT-INF/classes/com/xyz/resource.xml" and a package root of "BOOT-INF/classes/", returns "com/xyz/resource.xml". Also drops version prefixes for multi-version jars, for example for a resource path of "META-INF/versions/11/com/xyz/resource.xml" while running on JDK 9+, returns "com/xyz/resource.xml".

    • getPathRelativeToClasspathElement

      public String getPathRelativeToClasspathElement()
      Get the full path of this classpath resource relative to the root of the classpath element.
      Returns:
      the full path of this classpath resource within the classpath element. For example, will return the full path of "BOOT-INF/classes/com/xyz/resource.xml" or "META-INF/versions/11/com/xyz/resource.xml", not "com/xyz/resource.xml".

    • open

      public abstract InputStream open() throws IOException
      Open an InputStream for a classpath resource. Make sure you call close() when you are finished with the InputStream, so that the InputStream is closed.
      Returns:
      The opened InputStream.
      Throws:
      IOException - If the InputStream could not be opened.

    • read

      public abstract ByteBuffer read() throws IOException
      Open a ByteBuffer for a classpath resource. Make sure you call close() when you are finished with the ByteBuffer, so that the ByteBuffer is released or unmapped. See also readCloseable().
      Returns:
      The allocated or mapped ByteBuffer for the resource file content.
      Throws:
      IOException - If the resource could not be read.

    • readCloseable

      public CloseableByteBuffer readCloseable() throws IOException
      Open a ByteBuffer for a classpath resource, and wrap it in a CloseableByteBuffer instance, which implements the Closeable.close() method to free the underlying ByteBuffer when CloseableByteBuffer.close() is called, by automatically calling close().

      Call CloseableByteBuffer.getByteBuffer() on the returned instance to access the underlying ByteBuffer.

      Returns:
      The allocated or mapped ByteBuffer for the resource file content.
      Throws:
      IOException - If the resource could not be read.

    • load

      public abstract byte[] load() throws IOException
      Load a classpath resource and return its content as a byte array. Automatically calls close() after loading the byte array and before returning it, so that the underlying InputStream is closed or the underlying ByteBuffer is released or unmapped.
      Returns:
      The contents of the resource file.
      Throws:
      IOException - If the file contents could not be loaded in their entirety.

    • openClassfile

      abstract ClassfileReader openClassfile() throws IOException
      Open a ClassfileReader on the resource (for reading classfiles).
      Returns:
      the ClassfileReader.
      Throws:
      IOException - if an I/O exception occurs.

    • getLength

      public long getLength()
      Get the length of the resource.
      Returns:
      The length of the resource. This only reliably returns a valid value after calling open(), read(), or load() (and for open(), only if the underlying jarfile has length information for corresponding ZipEntry -- some jarfiles may not have length information in their zip entries). Returns -1L if the length is unknown.

    • getLastModified

      public abstract long getLastModified()
      Get the last modified time for the resource, in milliseconds since the epoch. This time is obtained from the directory entry, if this resource is a file on disk, or from the zipfile central directory, if this resource is a zipfile entry. Timestamps are not available for resources obtained from system modules or jlink'd modules.

      Note: The ZIP format has no notion of timezone, so timestamps are only meaningful if it is known what timezone they were created in. We arbitrarily assume that zipfile timestamps are in the UTC timezone. This may be a wrong assumption, so you may need to apply a timezone correction if you know the timezone used by the zipfile creator.

      Returns:
      The millis since the epoch indicating the date / time that this file resource was last modified. Returns 0L if the last modified date is unknown.

    • getPosixFilePermissions

      public abstract Set<PosixFilePermission> getPosixFilePermissions()
      Get the POSIX file permissions for the resource. POSIX file permissions are obtained from the directory entry, if this resource is a file on disk, or from the zipfile central directory, if this resource is a zipfile entry. POSIX file permissions are not available for resources obtained from system modules or jlink'd modules, and may not be available on non-POSIX-compliant operating systems or non-POSIX filesystems.
      Returns:
      The set of PosixFilePermission permission flags for the resource, or null if unknown.

    • toString

      public String toString()
      Get a string representation of the resource's location (as a URL string).
      Overrides:
      toString in class Object
      Returns:
      the resource location as a URL String.

    • hashCode

      public int hashCode()
      Hash code.
      Overrides:
      hashCode in class Object
      Returns:
      the int

    • equals

      public boolean equals(Object obj)
      Equals.
      Overrides:
      equals in class Object
      Parameters:
      obj - the obj
      Returns:
      true, if successful

    • compareTo

      public int compareTo(Resource o)
      Compare to.
      Specified by:
      compareTo in interface Comparable<Resource>
      Parameters:
      o - the o
      Returns:
      the int

    • close

      public void close()
      Close the underlying InputStream, or release/unmap the underlying ByteBuffer.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable