Class FileIo

java.lang.Object
com.codename1.backend.FileIo
public final class FileIo extends Object

The file-system calls a static handler needs, isolated so that everything else in StaticFiles -- ranges, conditional requests, MIME types, the containment check -- is pure Java and shared by every target. That logic is the part worth getting right once.

There is one of these per target: the translated one goes to open/fstat/sendfile directly, the Java SE one to the JDK's channels.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    BENEATH_UNSUPPORTED
    openBeneath cannot answer here; fall back to open plus a resolved-path check.
    static final int
    OPEN_FAILED
    openRead: the file is there and could not be opened.

  • Method Summary

    Modifier and Type
    Method
    Description
    static void
    close(int fd)
     
    static boolean
    hasSendFile()
    True when sendFile(int, int, long, long) is a kernel copy rather than a read/write loop.
    static int
    openBeneath(String root, String relative)
    A descriptor for relative under root, or -1.
    static int
    openRead(String path)
     
    static int
    read(int fd, byte[] buffer, int offset, int length)
     
    static String
    realPath(String path)
    The canonical path, symlinks followed.
    static long
    sendFile(int socketFd, int fileFd, long offset, long count)
    Sends bytes from a file straight to a socket, without them entering this process where the platform allows it.
    static int
    stat(int fd, long[] out)
    Fills out[0]=size, out[1]=modified-time-millis, out[2]=1 for a directory.
    static int
    statFresh(int fd, long[] out)
    The same call, because statImpl is a live fstat on the open descriptor and so is already current.

    Methods inherited from class Object

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

  • Field Details

    • BENEATH_UNSUPPORTED

      public static final int BENEATH_UNSUPPORTED
      openBeneath cannot answer here; fall back to open plus a resolved-path check.
      See Also:

    • OPEN_FAILED

      public static final int OPEN_FAILED
      openRead: the file is there and could not be opened. See openReadImpl.
      See Also:

  • Method Details

    • openBeneath

      public static int openBeneath(String root, String relative)

      A descriptor for relative under root, or -1. Never a file outside root, and never by checking afterwards: the kernel refuses the escape while it resolves, so there is no window between the open and the check for a symlink to move through.

      Returns BENEATH_UNSUPPORTED where the platform has no such call, so the caller can fall back rather than treat it as a missing file.

    • openRead

      public static int openRead(String path)

    • stat

      public static int stat(int fd, long[] out)
      Fills out[0]=size, out[1]=modified-time-millis, out[2]=1 for a directory. Taken from the OPEN DESCRIPTOR rather than the path: stat-then-open lets the file change in between, which is how a length header ends up disagreeing with the body.

    • statFresh

      public static int statFresh(int fd, long[] out)

      The same call, because statImpl is a live fstat on the open descriptor and so is already current.

      It exists so the two runtimes present one API: the Java SE implementation answers stat() from an open-time snapshot that asset serving needs, and therefore cannot answer whether the file has changed since. See the javadoc there.

    • sendFile

      public static long sendFile(int socketFd, int fileFd, long offset, long count)
      Sends bytes from a file straight to a socket, without them entering this process where the platform allows it. Returns how many moved, which may be fewer than asked; the caller loops.

    • hasSendFile

      public static boolean hasSendFile()
      True when sendFile(int, int, long, long) is a kernel copy rather than a read/write loop.

    • read

      public static int read(int fd, byte[] buffer, int offset, int length)

    • realPath

      public static String realPath(String path)
      The canonical path, symlinks followed. The static handler proves a resolved file is inside the document root with this: a check on the request string alone is defeated by an encoded traversal or by a symlink out of the tree.

    • close

      public static void close(int fd)