| |
| package javax.script; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| |
| import sun.misc.Service; |
| |
| /** |
| * ScriptEngineManager implements a discovery and instantiation |
| * mechanisams for ScriptEngine class. It also contains a collection |
| * of key-value pairs which storing state shared by all engines |
| * created by manager. |
| * |
| * Nandika Jayawardana <nandika@opensource.lk> |
| * Sanka Samaranayake <sanka@opensource.lk> |
| */ |
| public class ScriptEngineManager { |
| |
| /** Stores all instances of classes which implements |
| * ScriptEngineFactory which are found in resources |
| * META-INF/services/javax.script.ScriptEngineFactory |
| */ |
| protected HashSet engineSpis = new HashSet(); |
| |
| /** |
| * Stores language names with an associated |
| * ScriptEngineFactory |
| */ |
| protected HashMap nameAssociations = new HashMap(); |
| |
| /** |
| * Stores file extensions with an associated |
| * ScriptEngineFactory |
| */ |
| protected HashMap extensionAssocitions = new HashMap(); |
| |
| /** Stores MIME types with an associated ScriptEngineFactory */ |
| protected HashMap mimeTypeAssociations = new HashMap(); |
| |
| /** Stores the namespace associated with GLOBAL_SCOPE */ |
| protected Namespace globalscope = new SimpleNamespace(); |
| |
| /** |
| * Constructs ScriptEngineManager and initializes it. |
| */ |
| public ScriptEngineManager() { |
| |
| Iterator iterator = Service.providers(ScriptEngineFactory.class); |
| |
| while (iterator.hasNext()) { |
| ScriptEngineFactory factory = (ScriptEngineFactory) iterator.next(); |
| engineSpis.add(factory); |
| |
| String[] data = factory.getName(); |
| // gets all descriptinve names for Scripting Engine |
| for (int i=0; i<data.length; i++) { |
| nameAssociations.put(data[i], factory); |
| } |
| // gets all supported extensions |
| data = factory.getExtensions(); |
| for (int i=0; i<data.length; i++) { |
| extensionAssocitions.put(data[i], factory); |
| } |
| // gets all supported MIME types |
| data = factory.getMimeTypes(); |
| for (int i=0; i<data.length; i++) { |
| mimeTypeAssociations.put(data[i], factory); |
| } |
| } |
| } |
| |
| /** |
| * Retrieves the associated value for the spefied key in the |
| * GLOBAL_SCOPE |
| * |
| * @param key the associated key of the value stored in the |
| * GLOBAL_SCOPE |
| * @return the value associated with the specifed key |
| */ |
| public Object get(String key){ |
| return globalscope.get(key); |
| } |
| |
| /** |
| * Retrieves a new instance of a ScriptingEngine for the |
| * specified extension of a scirpt file. Returns null if no |
| * suitable ScriptingEngine is found. |
| * |
| * @param extension the specified extension of a script file |
| * @return a new instance of a ScriptingEngine which supports the |
| * specified script file extension |
| */ |
| public ScriptEngine getEngineByExtension(String extension){ |
| |
| ScriptEngine engine = null; |
| |
| ScriptEngineFactory factory = |
| (ScriptEngineFactory) extensionAssocitions.get(extension); |
| |
| if (factory != null) { |
| // gets a new instance of the Scripting Engine |
| engine = factory.getScriptEngine(); |
| // sets the GLOBAL SCOPE |
| engine.setNamespace(globalscope,ScriptContext.GLOBAL_SCOPE); |
| } |
| |
| return engine; |
| } |
| |
| /** |
| * Retrieves new instance the ScriptingEngine for a specifed MIME |
| * type. Returns null if no suitable ScriptingEngine is found. |
| * |
| * @param mimeType the specified MIME type |
| * @return a new instance of a ScriptingEngine which supports the |
| * specified MIME type |
| */ |
| public ScriptEngine getEngineByMimeType(String mimeType){ |
| |
| ScriptEngine engine = null; |
| ScriptEngineFactory factory = |
| (ScriptEngineFactory) mimeTypeAssociations.get(mimeType); |
| |
| if (factory != null) { |
| // gets a new instance of the Scripting Engine |
| engine = factory.getScriptEngine(); |
| // sets the GLOBAL SCOPE |
| engine.setNamespace(globalscope,ScriptContext.GLOBAL_SCOPE); |
| } |
| |
| return engine; |
| } |
| |
| /** |
| * Retrieves a new instance of a ScriptEngine the specified |
| * descriptieve name. Returns null if no suitable ScriptEngine is |
| * found. |
| * |
| * @param name the descriptive name |
| * @return a new instance of a ScriptEngine which supports the |
| * specifed descriptive name |
| */ |
| public ScriptEngine getEngineByName(String name){ |
| |
| ScriptEngine engine = null; |
| ScriptEngineFactory factory = |
| (ScriptEngineFactory) nameAssociations.get(name); |
| |
| if (factory != null) { |
| engine = factory.getScriptEngine(); |
| engine.setNamespace(globalscope,ScriptContext.GLOBAL_SCOPE); |
| } |
| |
| return engine; |
| } |
| |
| /** |
| * Retrieves an array of instances of ScriptEngineFactory class |
| * which are found by the discovery mechanism. |
| * |
| * @return an array of all discovered ScriptEngineFactory |
| * instances |
| */ |
| public ScriptEngineFactory[] getEngineFactories(){ |
| ArrayList factories = new ArrayList(); |
| Iterator iter = engineSpis.iterator(); |
| |
| while(iter.hasNext()) { |
| factories.add(iter.next()); |
| } |
| return (ScriptEngineFactory[]) factories.toArray( |
| new ScriptEngineFactory[factories.size()]); |
| } |
| |
| /** |
| * Retrieves the namespace corresponds to GLOBAL_SCOPE. |
| * |
| * @return the namespace of GLOBAL_SCOPE |
| */ |
| public Namespace getNamespace(){ |
| return globalscope; |
| } |
| |
| /** |
| * Associates the specifed value with the specified key in |
| * GLOBAL_SCOPE. |
| * |
| * @param key the associated key for specified value |
| * @param value the associated value for the specified key |
| */ |
| public void put(String key,Object value){ |
| globalscope.put(key,value); |
| } |
| |
| /** |
| * Register a extension with a ScriptEngineFactory class. It |
| * overrides any such association discovered previously. |
| * |
| * @param extension the extension associated with the specified |
| * ScriptEngineFactory class |
| * @param factory the ScriptEngineFactory class associated with |
| * the specified extension |
| */ |
| public void registerEngineExtension(String extension, Class factory){ |
| extensionAssocitions.put(extension, factory); |
| } |
| |
| /** |
| * Registers descriptive name with a ScriptEngineFactory class. |
| * It overrides any associations discovered previously. |
| * |
| * @param name a descriptive name associated with the specifed |
| * ScriptEngineFactory class |
| * @param factory the ScriptEngineFactory class associated with |
| * the specified descriptive name |
| */ |
| public void registerEngineName(String name, Class factory){ |
| nameAssociations.put(name, factory); |
| } |
| |
| /** |
| * Registers a MIME type with a ScriptEngineFactory class. It |
| * overrides any associations discovered previously. |
| * |
| * @param mimeType the MIME type associated with specified |
| * ScriptEngineFactory class |
| * @param factory the ScriptEngineFactory associated with the |
| * specified MIME type |
| */ |
| public void registerEngineMimeType(String mimeType,Class factory){ |
| mimeTypeAssociations.put(mimeType,factory); |
| } |
| |
| /** |
| * Sets the GLOBAL_SCOPE value to the specified namespace. |
| * |
| * @param namespace the namespace to be stored in GLOBAL_SCOPE |
| */ |
| public void setNamespace(Namespace namespace){ |
| globalscope = namespace; |
| } |
| } |