| /* |
| * 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; |
| |
| } |
| } |