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:
- the special value
Redirect.PIPE
- the special value
Redirect.INHERIT
- the special value
Redirect.DISCARD
- a redirection to read from a file, created by an invocation of
Redirect.from(File)
- a redirection to write to a file, created by an invocation of
Redirect.to(File)
- a redirection to append to a file, created by an invocation of
Redirect.appendTo(File)
Each of the above categories has an associated unique Type
.
- Since:
- 1.7
Nested Class Summary
Modifier and Type | Class | Description |
---|---|---|
static class | ProcessBuilder.Redirect.Type | The type of a |
Field Summary
Modifier and Type | Field | Description |
---|---|---|
static ProcessBuilder.Redirect | DISCARD | Indicates that subprocess output will be discarded. |
static ProcessBuilder.Redirect | INHERIT | Indicates that subprocess I/O source or destination will be the same as those of the current process. |
static 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 |
File | file() | Returns the |
static ProcessBuilder.Redirect | from(File file) | Returns a redirect to read from the specified file. |
int | hashCode() | Returns a hash code value for this |
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 |
Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
Field Detail
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 Detail
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
- TheFile
for theRedirect
. - 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
- TheFile
for theRedirect
. - 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
- TheFile
for theRedirect
. - 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 classObject
- 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 classObject
- Returns:
- a hash code value for this
Redirect
- See Also:
-
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)