Class ProcessBuilder.Redirect

java.lang.Object
java.lang.ProcessBuilder.Redirect
Enclosing class:
ProcessBuilder
public abstract static class ProcessBuilder.Redirect extends Object
Represents a source of subprocess input or a destination of subprocess output. Each Redirect instance is one of the following:

Each of the above categories has an associated unique Type.

Since:
1.7

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static enum 
    ProcessBuilder.Redirect.Type
    The type of a ProcessBuilder.Redirect.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final ProcessBuilder.Redirect
    DISCARD
    Indicates that subprocess output will be discarded.
    static final ProcessBuilder.Redirect
    INHERIT
    Indicates that subprocess I/O source or destination will be the same as those of the current process.
    static final ProcessBuilder.Redirect
    PIPE
    Indicates that subprocess I/O will be connected to the current Java process over a pipe.

  • Method Summary

    Modifier and Type
    Method
    Description
    static ProcessBuilder.Redirect
    appendTo(File file)
    Returns a redirect to append to the specified file.
    boolean
    equals(Object obj)
    Compares the specified object with this Redirect for equality.
    File
    file()
    Returns the File source or destination associated with this redirect, or null if there is no such file.
    static ProcessBuilder.Redirect
    from(File file)
    Returns a redirect to read from the specified file.
    int
    hashCode()
    Returns a hash code value for this Redirect.
    static ProcessBuilder.Redirect
    to(File file)
    Returns a redirect to write to the specified file.
    abstract ProcessBuilder.Redirect.Type
    type()
    Returns the type of this Redirect.

    Methods declared in class Object

    clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    May cause performance issues, deadlocks and hangs.
    final Class<? extends Object>
    getClass()
    Answers the unique instance of java.lang.Class which represents the class of the receiver.
    final void
    notify()
    Causes one thread which is waiting on the receiver to be made ready to run.
    final void
    notifyAll()
    Causes all threads which are waiting on the receiver to be made ready to run.
    String
    toString()
    Answers a string containing a concise, human-readable description of the receiver.
    final void
    wait()
    Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
    final void
    wait(long time)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
    final void
    wait(long time, int frac)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

  • Field Details

    • PIPE

      public static final ProcessBuilder.Redirect PIPE
      Indicates that subprocess I/O will be connected to the current Java process over a pipe. This is the default handling of subprocess standard I/O.

      It will always be true that 

          Redirect.PIPE.file() == null &&
    Redirect.PIPE.type() == Redirect.Type.PIPE

    • INHERIT

      public static final ProcessBuilder.Redirect INHERIT
      Indicates that subprocess I/O source or destination will be the same as those of the current process. This is the normal behavior of most operating system command interpreters (shells).

      It will always be true that 

          Redirect.INHERIT.file() == null &&
    Redirect.INHERIT.type() == Redirect.Type.INHERIT

    • DISCARD

      public static final ProcessBuilder.Redirect DISCARD
      Indicates that subprocess output will be discarded. A typical implementation discards the output by writing to an operating system specific "null file".

      It will always be true that 

          Redirect.DISCARD.file() != null && // is the filename appropriate for the operating system
    Redirect.DISCARD.type() == Redirect.Type.WRITE;
      Since:
      9

  • Method Details

    • type

      public abstract ProcessBuilder.Redirect.Type type()
      Returns the type of this Redirect.
      Returns:
      the type of this Redirect

    • file

      public File file()
      Returns the File source or destination associated with this redirect, or null if there is no such file.
      Returns:
      the file associated with this redirect, or null if there is no such file

    • from

      public static ProcessBuilder.Redirect from(File file)
      Returns a redirect to read from the specified file.

      It will always be true that 

          Redirect.from(file).file() == file &&
    Redirect.from(file).type() == Redirect.Type.READ
      Parameters:
      file - The File for the Redirect.
      Returns:
      a redirect to read from the specified file

    • to

      public static ProcessBuilder.Redirect to(File file)
      Returns a redirect to write to the specified file. If the specified file exists when the subprocess is started, its previous contents will be discarded.

      It will always be true that 

          Redirect.to(file).file() == file &&
    Redirect.to(file).type() == Redirect.Type.WRITE
      Parameters:
      file - The File for the Redirect.
      Returns:
      a redirect to write to the specified file

    • appendTo

      public static ProcessBuilder.Redirect appendTo(File file)
      Returns a redirect to append to the specified file. Each write operation first advances the position to the end of the file and then writes the requested data. Whether the advancement of the position and the writing of the data are done in a single atomic operation is system-dependent and therefore unspecified.

      It will always be true that 

          Redirect.appendTo(file).file() == file &&
    Redirect.appendTo(file).type() == Redirect.Type.APPEND
      Parameters:
      file - The File for the Redirect.
      Returns:
      a redirect to append to the specified file

    • equals

      public boolean equals(Object obj)
      Compares the specified object with this Redirect for equality. Returns true if and only if the two objects are identical or both objects are Redirect instances of the same type associated with non-null equal File instances.
      Overrides:
      equals in class Object
      Parameters:
      obj - Object the object to compare with this object.
      Returns:
      boolean true if the object is the same as this object false if it is different from this object.
      See Also:

    • hashCode

      public int hashCode()
      Returns a hash code value for this Redirect.
      Overrides:
      hashCode in class Object
      Returns:
      a hash code value for this Redirect
      See Also: