/* * 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.Set; /** * ScriptEngine is the fundamental interface whose methods must be * fully functional in every implementation of this specification. *

* These methods provide basic scripting functionality. Applications written to this * simple interface are expected to work with minimal modifications in every implementation. * It includes methods that execute scripts, and ones that set and get values. *

* The values are key/value pairs of two types. The first type of pairs consists of * those whose keys are reserved and defined in this specification or by individual * implementations. The values in the pairs with reserved keys have specified meanings. *

* The other type of pairs consists of those that create Java language Bindings, the values are * usually represented in scripts by the corresponding keys or by decorated forms of them. * * @author Mike Grogan * @since 1.6 */ public interface ScriptEngine { /** * Reserved key for a named value that passes * an array of positional arguments to a script. */ public static final String ARGV="javax.script.argv"; /** * Reserved key for a named value that is * the name of the file being executed. */ public static final String FILENAME = "javax.script.filename"; /** * Reserved key for a named value that is * the name of the ScriptEngine implementation. */ public static final String ENGINE = "javax.script.engine"; /** * Reserved key for a named value that identifies * the version of the ScriptEngine implementation. */ public static final String ENGINE_VERSION = "javax.script.engine_version"; /** * Reserved key for a named value that identifies * the short name of the scripting language. The name is used by the * ScriptEngineManager to locate a ScriptEngine * with a given name in the getEngineByName method. */ public static final String NAME = "javax.script.name"; /** * Reserved key for a named value that is * the full name of Scripting Language supported by the implementation. */ public static final String LANGUAGE = "javax.script.language"; /** * Reserved key for the named value that identifies * the version of the scripting language supported by the implementation. */ public static final String LANGUAGE_VERSION ="javax.script.language_version"; /** * Causes the immediate execution of the script whose source is the String * passed as the first argument. The script may be reparsed or recompiled before * execution. State left in the engine from previous executions, including * variable values and compiled procedures may be visible during this execution. * * @param script The script to be executed by the script engine. * * @param context A ScriptContext exposing sets of attributes in * different scopes. The meanings of the scopes ScriptContext.GLOBAL_SCOPE, * and ScriptContext.ENGINE_SCOPE are defined in the specification. *

* The ENGINE_SCOPE Bindings of the ScriptContext contains the * bindings of scripting variables to application objects to be used during this * script execution. * * * @return The value returned from the execution of the script. * * @throws ScriptException if an error occurs in script. ScriptEngines should create and throw * ScriptException wrappers for checked Exceptions thrown by underlying scripting * implementations. * @throws NullPointerException if either argument is null. */ public Object eval(String script, ScriptContext context) throws ScriptException; /** * Same as eval(String, ScriptContext) where the source of the script * is read from a Reader. * * @param reader The source of the script to be executed by the script engine. * * @param context The ScriptContext passed to the script engine. * * @return The value returned from the execution of the script. * * @throws ScriptException if an error occurs in script. ScriptEngines should create and throw * ScriptException wrappers for checked Exceptions thrown by underlying scripting * implementations. * @throws NullPointerException if either argument is null. */ public Object eval(Reader reader , ScriptContext context) throws ScriptException; /** * Executes the specified script. The default ScriptContext for the ScriptEngine * is used. * * @param script The script language source to be executed. * * @return The value returned from the execution of the script. * * @throws ScriptException if an error occurs in script. ScriptEngines should create and throw * ScriptException wrappers for checked Exceptions thrown by underlying scripting * implementations. * @throws NullPointerException if the argument is null. */ public Object eval(String script) throws ScriptException; /** * Same as eval(String) except that the source of the script is * provided as a Reader * * @param reader The source of the script. * * @return The value returned by the script. * * @throws ScriptException if an error occurs in script. ScriptEngines should create and throw * ScriptException wrappers for checked Exceptions thrown by underlying scripting * implementations. * @throws NullPointerException if the argument is null. */ public Object eval(Reader reader) throws ScriptException; /** * Executes the script using the Bindings argument as the ENGINE_SCOPE * Bindings of the ScriptEngine during the script execution. The * Reader, Writer and non-ENGINE_SCOPE Bindings of the * default ScriptContext are used. The ENGINE_SCOPE * Bindings of the ScriptEngine is not changed, and its * mappings are unaltered by the script execution. * * @param script The source for the script. * * @param n The Bindings of attributes to be used for script execution. * * @return The value returned by the script. * * @throws ScriptException if an error occurs in script. ScriptEngines should create and throw * ScriptException wrappers for checked Exceptions thrown by underlying scripting * implementations. * @throws NullPointerException if either argument is null. */ public Object eval(String script, Bindings n) throws ScriptException; /** * Same as eval(String, Bindings) except that the source of the script * is provided as a Reader. * * @param reader The source of the script. * @param n The Bindings of attributes. * * @return The value returned by the script. * * @throws ScriptException if an error occurs in script. ScriptEngines should create and throw * ScriptException wrappers for checked Exceptions thrown by underlying scripting * implementations. * @throws NullPointerException if either argument is null. */ public Object eval(Reader reader , Bindings n) throws ScriptException; /** * Sets a key/value pair in the state of the ScriptEngine that may either create * a Java Language Binding to be used in the execution of scripts or be used in some * other way, depending on whether the key is reserved. Must have the same effect as * getBindings(ScriptContext.ENGINE_SCOPE).put. * * @param key The name of named value to add * @param value The value of named value to add. * * @throws NullPointerException if key is null. * @throws IllegalArgumentException if key is empty. */ public void put(String key, Object value); /** * Retrieves a value set in the state of this engine. The value might be one * which was set using setValue or some other value in the state * of the ScriptEngine, depending on the implementation. Must have the same effect * as getBindings(ScriptContext.ENGINE_SCOPE).get * * @param key The key whose value is to be returned * @return the value for the given key * * @throws NullPointerException if key is null. * @throws IllegalArgumentException if key is empty. */ public Object get(String key); /** * Returns a scope of named values. The possible scopes are: *

* *

* The Bindings instances that are returned must be identical to those returned by the * getBindings method of ScriptContext called with corresponding arguments on * the default ScriptContext of the ScriptEngine. * * @param scope Either ScriptContext.ENGINE_SCOPE or ScriptContext.GLOBAL_SCOPE * which specifies the Bindings to return. Implementations of ScriptContext * may define additional scopes. If the default ScriptContext of the ScriptEngine * defines additional scopes, any of them can be passed to get the corresponding Bindings. * * @return The Bindings with the specified scope. * * @throws IllegalArgumentException if specified scope is invalid * */ public Bindings getBindings(int scope); /** * Sets a scope of named values to be used by scripts. The possible scopes are: *

* *

* The method must have the same effect as calling the setBindings method of * ScriptContext with the corresponding value of scope on the default * ScriptContext of the ScriptEngine. * * @param bindings The Bindings for the specified scope. * @param scope The specified scope. Either ScriptContext.ENGINE_SCOPE, * ScriptContext.GLOBAL_SCOPE, or any other valid value of scope. * * @throws IllegalArgumentException if the scope is invalid * @throws NullPointerException if the bindings is null and the scope is * ScriptContext.ENGINE_SCOPE */ public void setBindings(Bindings bindings, int scope); /** * Returns an uninitialized Bindings. * * @return A Bindings that can be used to replace the state of this ScriptEngine. **/ public Bindings createBindings(); /** * Returns the default ScriptContext of the ScriptEngine whose Bindings, Reader * and Writers are used for script executions when no ScriptContext is specified. * * @return The default ScriptContext of the ScriptEngine. */ public ScriptContext getContext(); /** * Sets the default ScriptContext of the ScriptEngine whose Bindings, Reader * and Writers are used for script executions when no ScriptContext is specified. * * @param context A ScriptContext that will replace the default ScriptContext in * the ScriptEngine. * @throws NullPointerException if context is null. */ public void setContext(ScriptContext context); /** * Returns a ScriptEngineFactory for the class to which this ScriptEngine belongs. * * @return The ScriptEngineFactory */ public ScriptEngineFactory getFactory(); }