Java compact1, compact2, compact3 java.lang Class Process（JDK8）

Constructor Detail

• Process

  public Process()

Method Detail

• getOutputStream

  public abstract OutputStream getOutputStream()

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

  If the standard input of the subprocess has been redirected using ProcessBuilder.redirectInput then this method will return a null output stream.

  Implementation note: It is a good idea for the returned output stream to be buffered.

  Returns:

  the output stream connected to the normal input of the subprocess

• getInputStream

  public abstract InputStream getInputStream()

  Returns the input stream connected to the normal output of the subprocess. The stream obtains data piped from the standard output of the process represented by this Process object.

  If the standard output of the subprocess has been redirected using ProcessBuilder.redirectOutput then this method will return a null input stream.

  Otherwise, if the standard error of the subprocess has been redirected using ProcessBuilder.redirectErrorStream then the input stream returned by this method will receive the merged standard output and the standard error of the subprocess.

  Implementation note: It is a good idea for the returned input stream to be buffered.

  Returns:

  the input stream connected to the normal output of the subprocess

• getErrorStream

  public abstract InputStream getErrorStream()

  Returns the input stream connected to the error output of the subprocess. The stream obtains data piped from the error output of the process represented by this Process object.

  If the standard error of the subprocess has been redirected using ProcessBuilder.redirectError or ProcessBuilder.redirectErrorStream then this method will return a null input stream.

  Implementation note: It is a good idea for the returned input stream to be buffered.

  Returns:

  the input stream connected to the error output of the subprocess

• waitFor

  public abstract int waitFor()
                       throws InterruptedException

  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 subprocess represented by this Process object. By convention, the value 0 indicates normal termination.

  Throws:

  InterruptedException - if the current thread is interrupted by another thread while it is waiting, then the wait is ended and an InterruptedException is thrown.

• waitFor

  public boolean waitFor(long timeout,
                         TimeUnit unit)
                  throws InterruptedException

  Causes the current thread to wait, if necessary, until the subprocess represented by this Process object has terminated, or the specified waiting time elapses.

  If the subprocess has already terminated then this method returns immediately with the value true. If the process has not terminated and the timeout value is less than, or equal to, zero, then this method returns immediately with the value false.

  The default implementation of this methods polls the exitValue to check if the process has terminated. Concrete implementations of this class are strongly encouraged to override this method with a more efficient implementation.

  Parameters:

  timeout - the maximum time to wait

  unit - the time unit of the timeout argument

  Returns:

  true if the subprocess has exited and false if the waiting time elapsed before the subprocess has exited.

  Throws:

  InterruptedException - if the current thread is interrupted while waiting.

  NullPointerException - if unit is null

  Since:

  1.8

• exitValue

  public abstract int exitValue()

  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

• destroy

  public abstract void destroy()

  Kills the subprocess. Whether the subprocess represented by this Process object is forcibly terminated or not is implementation dependent.

• destroyForcibly

  public Process destroyForcibly()

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

  The default implementation of this method invokes destroy() and so may not forcibly terminate the process. Concrete implementations of this class are strongly encouraged to override this method with a compliant implementation. Invoking this method on Process objects returned by ProcessBuilder.start() and Runtime.exec(java.lang.String) will forcibly terminate the process.

  Note: The subprocess may not terminate immediately. i.e. isAlive() may return true for a brief period after destroyForcibly() is called. This method may be chained to waitFor() if needed.

  Returns:

  the Process object representing the subprocess to be forcibly destroyed.

  Since:

  1.8

• isAlive

  public boolean isAlive()

  Tests whether the subprocess represented by this Process is alive.

  Returns:

  true if the subprocess represented by this Process object has not yet terminated.

  Since:

  1.8