java.lang.Object java.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 io (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.
Constructor Summary | |
---|---|
Process
() |
Method Summary | |
---|---|
abstract void |
destroy
() Kills the subprocess. |
abstract int |
exitValue
() Returns the exit value for the subprocess. |
abstract InputStream |
getErrorStream
() Gets the error stream of the subprocess. |
abstract InputStream |
getInputStream
() Gets the input stream of the subprocess. |
abstract OutputStream |
getOutputStream
() Gets the output stream 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 |
---|
clone , equals , finalize , getClass , hashCode , notify , notifyAll , toString , wait , wait , wait |
Constructor Detail |
---|
public Process()
Method Detail |
---|
public abstract OutputStream getOutputStream()
Implementation note: It is a good idea for the output stream to be buffered.
public abstract InputStream getInputStream()
Implementation note: It is a good idea for the input stream to be buffered.
public abstract InputStream getErrorStream()
Implementation note: It is a good idea for the input stream to be buffered.
public abstract int waitFor() throws InterruptedException
public abstract int exitValue()
public abstract void destroy()