diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/java.scripting/share/classes/javax/script/AbstractScriptEngine.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.scripting/share/classes/javax/script/AbstractScriptEngine.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,311 @@
+/*
+ * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package javax.script;
+import java.io.Reader;
+import java.util.Map;
+import java.util.Iterator;
+
+/**
+ * Provides a standard implementation for several of the variants of the <code>eval</code>
+ * method.
+ * <br><br>
+ * <code><b>eval(Reader)</b></code><p><code><b>eval(String)</b></code><p>
+ * <code><b>eval(String, Bindings)</b></code><p><code><b>eval(Reader, Bindings)</b></code>
+ * <br><br> are implemented using the abstract methods
+ * <br><br>
+ * <code><b>eval(Reader,ScriptContext)</b></code> or
+ * <code><b>eval(String, ScriptContext)</b></code>
+ * <br><br>
+ * with a <code>SimpleScriptContext</code>.
+ * <br><br>
+ * A <code>SimpleScriptContext</code> is used as the default <code>ScriptContext</code>
+ * of the <code>AbstractScriptEngine</code>..
+ *
+ * @author Mike Grogan
+ * @since 1.6
+ */
+public abstract class AbstractScriptEngine  implements ScriptEngine {
+
+    /**
+     * The default <code>ScriptContext</code> of this <code>AbstractScriptEngine</code>.
+     */
+
+    protected ScriptContext context;
+
+    /**
+     * Creates a new instance of AbstractScriptEngine using a <code>SimpleScriptContext</code>
+     * as its default <code>ScriptContext</code>.
+     */
+    public AbstractScriptEngine() {
+
+        context = new SimpleScriptContext();
+
+    }
+
+    /**
+     * Creates a new instance using the specified <code>Bindings</code> as the
+     * <code>ENGINE_SCOPE</code> <code>Bindings</code> in the protected <code>context</code> field.
+     *
+     * @param n The specified <code>Bindings</code>.
+     * @throws NullPointerException if n is null.
+     */
+    public AbstractScriptEngine(Bindings n) {
+
+        this();
+        if (n == null) {
+            throw new NullPointerException("n is null");
+        }
+        context.setBindings(n, ScriptContext.ENGINE_SCOPE);
+    }
+
+    /**
+     * Sets the value of the protected <code>context</code> field to the specified
+     * <code>ScriptContext</code>.
+     *
+     * @param ctxt The specified <code>ScriptContext</code>.
+     * @throws NullPointerException if ctxt is null.
+     */
+    public void setContext(ScriptContext ctxt) {
+        if (ctxt == null) {
+            throw new NullPointerException("null context");
+        }
+        context = ctxt;
+    }
+
+    /**
+     * Returns the value of the protected <code>context</code> field.
+     *
+     * @return The value of the protected <code>context</code> field.
+     */
+    public ScriptContext getContext() {
+        return context;
+    }
+
+    /**
+     * Returns the <code>Bindings</code> with the specified scope value in
+     * the protected <code>context</code> field.
+     *
+     * @param scope The specified scope
+     *
+     * @return The corresponding <code>Bindings</code>.
+     *
+     * @throws IllegalArgumentException if the value of scope is
+     * invalid for the type the protected <code>context</code> field.
+     */
+    public Bindings getBindings(int scope) {
+
+        if (scope == ScriptContext.GLOBAL_SCOPE) {
+            return context.getBindings(ScriptContext.GLOBAL_SCOPE);
+        } else if (scope == ScriptContext.ENGINE_SCOPE) {
+            return context.getBindings(ScriptContext.ENGINE_SCOPE);
+        } else {
+            throw new IllegalArgumentException("Invalid scope value.");
+        }
+    }
+
+    /**
+     * Sets the <code>Bindings</code> with the corresponding scope value in the
+     * <code>context</code> field.
+     *
+     * @param bindings The specified <code>Bindings</code>.
+     * @param scope The specified scope.
+     *
+     * @throws IllegalArgumentException if the value of scope is
+     * invalid for the type the <code>context</code> field.
+     * @throws NullPointerException if the bindings is null and the scope is
+     * <code>ScriptContext.ENGINE_SCOPE</code>
+     */
+    public void setBindings(Bindings bindings, int scope) {
+
+        if (scope == ScriptContext.GLOBAL_SCOPE) {
+            context.setBindings(bindings, ScriptContext.GLOBAL_SCOPE);;
+        } else if (scope == ScriptContext.ENGINE_SCOPE) {
+            context.setBindings(bindings, ScriptContext.ENGINE_SCOPE);;
+        } else {
+            throw new IllegalArgumentException("Invalid scope value.");
+        }
+    }
+
+    /**
+     * Sets the specified value with the specified key in the <code>ENGINE_SCOPE</code>
+     * <code>Bindings</code> of the protected <code>context</code> field.
+     *
+     * @param key The specified key.
+     * @param value The specified value.
+     *
+     * @throws NullPointerException if key is null.
+     * @throws IllegalArgumentException if key is empty.
+     */
+    public void put(String key, Object value) {
+
+        Bindings nn = getBindings(ScriptContext.ENGINE_SCOPE);
+        if (nn != null) {
+            nn.put(key, value);
+        }
+
+    }
+
+    /**
+     * Gets the value for the specified key in the <code>ENGINE_SCOPE</code> of the
+     * protected <code>context</code> field.
+     *
+     * @return The value for the specified key.
+     *
+     * @throws NullPointerException if key is null.
+     * @throws IllegalArgumentException if key is empty.
+     */
+    public Object get(String key) {
+
+        Bindings nn = getBindings(ScriptContext.ENGINE_SCOPE);
+        if (nn != null) {
+            return nn.get(key);
+        }
+
+        return null;
+    }
+
+
+    /**
+     * <code>eval(Reader, Bindings)</code> calls the abstract
+     * <code>eval(Reader, ScriptContext)</code> method, passing it a <code>ScriptContext</code>
+     * whose Reader, Writers and Bindings for scopes other that <code>ENGINE_SCOPE</code>
+     * are identical to those members of the protected <code>context</code> field.  The specified
+     * <code>Bindings</code> is used instead of the <code>ENGINE_SCOPE</code>
+     *
+     * <code>Bindings</code> of the <code>context</code> field.
+     *
+     * @param reader A <code>Reader</code> containing the source of the script.
+     * @param bindings A <code>Bindings</code> to use for the <code>ENGINE_SCOPE</code>
+     * while the script executes.
+     *
+     * @return The return value from <code>eval(Reader, ScriptContext)</code>
+     * @throws ScriptException if an error occurs in script.
+     * @throws NullPointerException if any of the parameters is null.
+     */
+    public Object eval(Reader reader, Bindings bindings ) throws ScriptException {
+
+        ScriptContext ctxt = getScriptContext(bindings);
+
+        return eval(reader, ctxt);
+    }
+
+
+    /**
+     * Same as <code>eval(Reader, Bindings)</code> except that the abstract
+     * <code>eval(String, ScriptContext)</code> is used.
+     *
+     * @param script A <code>String</code> containing the source of the script.
+     *
+     * @param bindings A <code>Bindings</code> to use as the <code>ENGINE_SCOPE</code>
+     * while the script executes.
+     *
+     * @return The return value from <code>eval(String, ScriptContext)</code>
+     * @throws ScriptException if an error occurs in script.
+     * @throws NullPointerException if any of the parameters is null.
+     */
+    public Object eval(String script, Bindings bindings) throws ScriptException {
+
+        ScriptContext ctxt = getScriptContext(bindings);
+
+        return eval(script , ctxt);
+    }
+
+    /**
+     * <code>eval(Reader)</code> calls the abstract
+     * <code>eval(Reader, ScriptContext)</code> passing the value of the <code>context</code>
+     * field.
+     *
+     * @param reader A <code>Reader</code> containing the source of the script.
+     * @return The return value from <code>eval(Reader, ScriptContext)</code>
+     * @throws ScriptException if an error occurs in script.
+     * @throws NullPointerException if any of the parameters is null.
+     */
+    public Object eval(Reader reader) throws ScriptException {
+
+
+        return eval(reader, context);
+    }
+
+    /**
+     * Same as <code>eval(Reader)</code> except that the abstract
+     * <code>eval(String, ScriptContext)</code> is used.
+     *
+     * @param script A <code>String</code> containing the source of the script.
+     * @return The return value from <code>eval(String, ScriptContext)</code>
+     * @throws ScriptException if an error occurs in script.
+     * @throws NullPointerException if any of the parameters is null.
+     */
+    public Object eval(String script) throws ScriptException {
+
+
+        return eval(script, context);
+    }
+
+    /**
+     * Returns a <code>SimpleScriptContext</code>.  The <code>SimpleScriptContext</code>:
+     *<br><br>
+     * <ul>
+     * <li>Uses the specified <code>Bindings</code> for its <code>ENGINE_SCOPE</code>
+     * </li>
+     * <li>Uses the <code>Bindings</code> returned by the abstract <code>getGlobalScope</code>
+     * method as its <code>GLOBAL_SCOPE</code>
+     * </li>
+     * <li>Uses the Reader and Writer in the default <code>ScriptContext</code> of this
+     * <code>ScriptEngine</code>
+     * </li>
+     * </ul>
+     * <br><br>
+     * A <code>SimpleScriptContext</code> returned by this method is used to implement eval methods
+     * using the abstract <code>eval(Reader,Bindings)</code> and <code>eval(String,Bindings)</code>
+     * versions.
+     *
+     * @param nn Bindings to use for the <code>ENGINE_SCOPE</code>
+     * @return The <code>SimpleScriptContext</code>
+     */
+    protected ScriptContext getScriptContext(Bindings nn) {
+
+        SimpleScriptContext ctxt = new SimpleScriptContext();
+        Bindings gs = getBindings(ScriptContext.GLOBAL_SCOPE);
+
+        if (gs != null) {
+            ctxt.setBindings(gs, ScriptContext.GLOBAL_SCOPE);
+        }
+
+        if (nn != null) {
+            ctxt.setBindings(nn,
+                    ScriptContext.ENGINE_SCOPE);
+        } else {
+            throw new NullPointerException("Engine scope Bindings may not be null.");
+        }
+
+        ctxt.setReader(context.getReader());
+        ctxt.setWriter(context.getWriter());
+        ctxt.setErrorWriter(context.getErrorWriter());
+
+        return ctxt;
+
+    }
+}