1 /*
   2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.jshell.spi;
  27 
  28 import java.io.InputStream;
  29 import java.io.PrintStream;
  30 import java.util.List;
  31 import jdk.jshell.JShell;
  32 
  33 /**
  34  * Functionality made available to a pluggable JShell execution engine.  It is
  35  * provided to the execution engine by the core JShell implementation.
  36  * <p>
  37  * This interface is designed to provide the access to core JShell functionality
  38  * needed to implement ExecutionControl.
  39  *
  40  * @see ExecutionControl
  41  */
  42 public interface ExecutionEnv {
  43 
  44     /**
  45      * Returns the user's input stream.
  46      *
  47      * @return the user's input stream
  48      */
  49     InputStream userIn();
  50 
  51     /**
  52      * Returns the user's output stream.
  53      *
  54      * @return the user's output stream
  55      */
  56     PrintStream userOut();
  57 
  58     /**
  59      * Returns the user's error stream.
  60      *
  61      * @return the user's error stream
  62      */
  63     PrintStream userErr();
  64 
  65     /**
  66      * @return the JShell instance
  67      */
  68     JShell state();
  69 
  70     /**
  71      * Returns the additional VM options to be used when launching the remote
  72      * JVM. This is advice to the execution engine.
  73      * <p>
  74      * Note: an execution engine need not launch a remote JVM.
  75      *
  76      * @return the additional options with which to launch the remote JVM
  77      */
  78     List<String> extraRemoteVMOptions();
  79 
  80     /**
  81      * Reports that the execution engine has shutdown.
  82      */
  83     void closeDown();
  84 
  85 }