/* * Copyright (c) 2005, 2011, 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.util.Map; /** * Extended by classes that store results of compilations.  State * might be stored in the form of Java classes, Java class files or scripting * language opcodes.  The script may be executed repeatedly * without reparsing. * <br><br> * Each <code>CompiledScript</code> is associated with a <code>ScriptEngine</code> -- A call to an  <code>eval</code> * method of the <code>CompiledScript</code> causes the execution of the script by the * <code>ScriptEngine</code>.  Changes in the state of the <code>ScriptEngine</code> caused by execution * of tne <code>CompiledScript</code>  may visible during subsequent executions of scripts by the engine. * * @author Mike Grogan * @since 1.6 */public abstract class CompiledScript {     /**     * Executes the program stored in this <code>CompiledScript</code> object.     *     * @param context A <code>ScriptContext</code> that is used in the same way as     * the <code>ScriptContext</code> passed to the <code>eval</code> methods of     * <code>ScriptEngine</code>.     *     * @return The value returned by the script execution, if any.  Should return <code>null</code>     * if no value is returned by the script execution.     *     * @throws ScriptException if an error occurs.     * @throws NullPointerException if context is null.     */     public abstract Object eval(ScriptContext context) throws ScriptException;     /**     * Executes the program stored in the <code>CompiledScript</code> object using     * the supplied <code>Bindings</code> of attributes as the <code>ENGINE_SCOPE</code> of the     * associated <code>ScriptEngine</code> during script execution.  If bindings is null,     * then the effect of calling this method is same as that of eval(getEngine().getContext()).     * <p>.     * The <code>GLOBAL_SCOPE</code> <code>Bindings</code>, <code>Reader</code> and <code>Writer</code>     * associated with the default <code>ScriptContext</code> of the associated <code>ScriptEngine</code> are used.     *     * @param bindings The bindings of attributes used for the <code>ENGINE_SCOPE</code>.     *     * @return The return value from the script execution     *     * @throws ScriptException if an error occurs.     */    public Object eval(Bindings bindings) throws ScriptException {         ScriptContext ctxt = getEngine().getContext();         if (bindings != null) {            SimpleScriptContext tempctxt = new SimpleScriptContext();            tempctxt.setBindings(bindings, ScriptContext.ENGINE_SCOPE);            tempctxt.setBindings(ctxt.getBindings(ScriptContext.GLOBAL_SCOPE),                    ScriptContext.GLOBAL_SCOPE);            tempctxt.setWriter(ctxt.getWriter());            tempctxt.setReader(ctxt.getReader());            tempctxt.setErrorWriter(ctxt.getErrorWriter());            ctxt = tempctxt;        }         return eval(ctxt);    }      /**     * Executes the program stored in the <code>CompiledScript</code> object.  The     * default <code>ScriptContext</code> of the associated <code>ScriptEngine</code> is used.     * The effect of calling this method is same as that of eval(getEngine().getContext()).     *     * @return The return value from the script execution     *     * @throws ScriptException if an error occurs.     */    public Object eval() throws ScriptException {        return eval(getEngine().getContext());    }     /**     * Returns the <code>ScriptEngine</code> whose <code>compile</code> method created this <code>CompiledScript</code>.     * The <code>CompiledScript</code> will execute in this engine.     *     * @return The <code>ScriptEngine</code> that created this <code>CompiledScript</code>     */    public abstract ScriptEngine getEngine(); }