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Java™ Platform Standard Ed. 6 |
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java.lang.Objectjava.lang.Process
public abstract class Process
The ProcessBuilder.start()
and
Runtime.exec
methods create a native process and return an instance of a
subclass of Process
that can be used to control the process
and obtain information about it. The class Process
provides methods for performing input from the process, performing
output to the process, waiting for the process to complete,
checking the exit status of the process, and destroying (killing)
the process.
The methods that create processes may not work well for special
processes on certain native platforms, such as native windowing
processes, daemon processes, Win16/DOS processes on Microsoft
Windows, or shell scripts. The created subprocess does not have
its own terminal or console. All its standard I/O (i.e. stdin,
stdout, stderr) operations will be redirected to the parent process
through three streams
(getOutputStream()
,
getInputStream()
,
getErrorStream()
).
The parent process uses these streams to feed input to and get output
from the subprocess. Because some native platforms only provide
limited buffer size for standard input and output streams, failure
to promptly write the input stream or read the output stream of
the subprocess may cause the subprocess to block, and even deadlock.
The subprocess is not killed when there are no more references to
the Process
object, but rather the subprocess
continues executing asynchronously.
There is no requirement that a process represented by a Process
object execute asynchronously or concurrently with respect
to the Java process that owns the Process
object.
ProcessBuilder
Constructor Summary | |
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Process()
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Method Summary | |
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abstract void |
destroy()
Kills the subprocess. |
abstract int |
exitValue()
Returns the exit value for the subprocess. |
abstract InputStream |
getErrorStream()
Returns the input stream connected to the error output stream of the subprocess. |
abstract InputStream |
getInputStream()
Returns the input stream connected to the normal output of the subprocess. |
abstract OutputStream |
getOutputStream()
Returns the output stream connected to the normal input of the subprocess. |
abstract int |
waitFor()
Causes the current thread to wait, if necessary, until the process represented by this Process object has
terminated. |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
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public Process()
Method Detail |
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public abstract OutputStream getOutputStream()
Process
object.
Implementation note: It is a good idea for the returned output stream to be buffered.
public abstract InputStream getInputStream()
Process
object.
Implementation note: It is a good idea for the returned input stream to be buffered.
ProcessBuilder.redirectErrorStream()
public abstract InputStream getErrorStream()
Process
object.
Implementation note: It is a good idea for the returned input stream to be buffered.
ProcessBuilder.redirectErrorStream()
public abstract int waitFor() throws InterruptedException
Process
object has
terminated. This method returns immediately if the subprocess
has already terminated. If the subprocess has not yet
terminated, the calling thread will be blocked until the
subprocess exits.
Process
object. By convention, the value
0
indicates normal termination.
InterruptedException
- if the current thread is
interrupted by another
thread while it is waiting, then the wait is ended and
an InterruptedException
is thrown.public abstract int exitValue()
Process
object. By convention, the value
0
indicates normal termination.
IllegalThreadStateException
- if the subprocess represented
by this Process
object has not yet terminatedpublic abstract void destroy()
Process
object is forcibly terminated.
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Java™ Platform Standard Ed. 6 |
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Copyright 2010 Sun Microsystems, Inc. All rights reserved. Use is subject to the terms of the GNU General Public License.