Process JDK 1.6)

Description

publicabstract 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 io (i.e. stdin, stdout, stderr) operations will be redirected to the parent process through three streams (Process.getOutputStream(), Process.getInputStream(), Process.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.

See also: ProcessBuilder Runtime.exec(String[], String[], File)

Methods

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publicabstract void destroy ()

Kills the subprocess.

Kills the subprocess. The subprocess represented by this
Process object is forcibly terminated.

publicabstract int exitValue ()

Returns the exit value for the subprocess.

Returns the exit value for the subprocess.
Returns: the exit value of the subprocess represented by this Process object. by convention, the value 0 indicates normal termination.
Throws:
- IllegalThreadStateException - if the subprocess represented by this Process object has not yet terminated.

publicabstract InputStream getErrorStream ()

Gets the error stream of the subprocess.

Gets the error stream of the subprocess. The stream obtains data piped from the error output stream of the process represented by this Process object.

Implementation note: It is a good idea for the input stream to be buffered.
Returns: the input stream connected to the error stream of the subprocess.
See Also: ProcessBuilder.redirectErrorStream(),

publicabstract InputStream getInputStream ()

Gets the input stream of the subprocess.

Gets the input stream of the subprocess. The stream obtains data piped from the standard output stream of the process represented by this Process object.

Implementation note: It is a good idea for the input stream to be buffered.
Returns: the input stream connected to the normal output of the subprocess.
See Also: ProcessBuilder.redirectErrorStream(),

publicabstract OutputStream getOutputStream ()

Gets the output stream of the subprocess.

Gets the output stream of the subprocess. Output to the stream is piped into the standard input stream of the process represented by this Process object.

Implementation note: It is a good idea for the output stream to be buffered.
Returns: the output stream connected to the normal input of the subprocess.

publicabstract int waitFor () throws InterruptedException

causes the current thread to wait, if necessary, until the process represented by this Process object has terminated.

causes the current thread to wait, if necessary, until the
process represented by this 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.
Returns: the exit value of the process. By convention, 0 indicates normal termination.
Throws:
- InterruptedException - if the current thread is {@linkplain Thread#interrupt() interrupted} by another thread while it is waiting, then the wait is ended and an {@link InterruptedException} is thrown.