Module java.base
Package java.lang

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

  • 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() is the filename appropriate for the operating system
 and may be null &&
 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 - the reference object with which to compare.
      Returns:
      true if this object is the same as the obj argument; false otherwise.
      See Also:
      Object.hashCode(), HashMap

    • 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:
      Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)