THE PACKAGE JAVA.LANG

java.lang.Process

20.15

20.15 The Class

java.lang.Process

The method

exec

 ( 20.16.3) of class

Runtime

 returns a reference to a

Process

object. The class

Process

 provides methods for performing input from the pro 

cess, performing output to the process, waiting for the process to complete, check 

ing the exit status of the process, and destroying (killing) the process.

Dropping the last reference to a

Process

 instance, thus allowing the

Process

object to be reclaimed, does

not

 automatically kill the associated process.

There is no requirement that a process represented by a

Process

 object exe 

cute asynchronously or concurrently with respect to the Java process that owns the

Process

 object.

public abstract class Process {

public abstract OutputStream getOutputStream();

public abstract InputStream getInputStream();

public abstract InputStream getErrorStream();

public abstract int waitFor()

throws InterruptedException;

public abstract int exitValue()

throws IllegalThreadStateException;

public abstract void destroy();

}

20.15.1

public abstract OutputStream getOutputStream()

This method returns an

OutputStream

. 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.

20.15.2

public abstract InputStream getInputStream()

This method returns an

InputStream

. 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.

20.15.3

public abstract InputStream getErrorStream()

This method returns an

InputStream

. 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.

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