ScriptEngineFactory is used to describe and instantiate
* ScriptEngines.
* ScriptEngine has a corresponding factory
* that exposes metadata describing the engine class.
* ScriptEngineManager
* uses the service provider mechanism described in the Jar File Specification to obtain
* instances of all ScriptEngineFactories available in
* the current ClassLoader.
*
* @since 1.6
*/
public interface ScriptEngineFactory {
/**
* Returns the full name of the ScriptEngine. For
* instance an implementation based on the Mozilla Rhino Javascript engine
* might return Rhino Mozilla Javascript Engine.
* @return The name of the engine implementation.
*/
public String getEngineName();
/**
* Returns the version of the ScriptEngine.
* @return The ScriptEngine implementation version.
*/
public String getEngineVersion();
/**
* Returns an immutable list of filename extensions, which generally identify scripts
* written in the language supported by this ScriptEngine.
* The array is used by the ScriptEngineManager to implement its
* getEngineByExtension method.
* @return The list of extensions.
*/
public ListScriptEngineManager class to implement its
* getEngineByMimetype method.
* @return The list of mime types.
*/
public ListScriptEngine, which may be used to
* identify the ScriptEngine by the ScriptEngineManager.
* For instance, an implementation based on the Mozilla Rhino Javascript engine might
* return list containing {"javascript", "rhino"}.
*/
public ListScriptEngine.
* @return The name of the supported language.
*/
public String getLanguageName();
/**
* Returns the version of the scripting language supported by this
* ScriptEngine.
* @return The version of the supported language.
*/
public String getLanguageVersion();
/**
* Returns the value of an attribute whose meaning may be implementation-specific.
* Keys for which the value is defined in all implementations are:
*
* The values for these keys are the Strings returned by getEngineName,
* getEngineVersion, getName, getLanguageName and
* getLanguageVersion respectively.
* A reserved key, THREADING, whose value describes the behavior of the engine
* with respect to concurrent execution of scripts and maintenance of state is also defined.
* These values for the THREADING key are:
*
null - The engine implementation is not thread safe, and cannot
* be used to execute scripts concurrently on multiple threads.
* "MULTITHREADED" - The engine implementation is internally
* thread-safe and scripts may execute concurrently although effects of script execution
* on one thread may be visible to scripts on other threads.
* "THREAD-ISOLATED" - The implementation satisfies the requirements
* of "MULTITHREADED", and also, the engine maintains independent values
* for symbols in scripts executing on different threads.
* "STATELESS" - The implementation satisfies the requirements of
* "THREAD-ISOLATED". In addition, script executions do not alter the
* mappings in the Bindings which is the engine scope of the
* ScriptEngine. In particular, the keys in the Bindings
* and their associated values are the same before and after the execution of the script.
* null if no
* value is assigned to the key.
*
*/
public Object getParameter(String key);
/**
* Returns a String which can be used to invoke a method of a Java object using the syntax
* of the supported scripting language. For instance, an implementaton for a Javascript
* engine might be;
* *
{@code
* public String getMethodCallSyntax(String obj,
* String m, String... args) {
* String ret = obj;
* ret += "." + m + "(";
* for (int i = 0; i < args.length; i++) {
* ret += args[i];
* if (i < args.length - 1) {
* ret += ",";
* }
* }
* ret += ")";
* return ret;
* }
* }
*
*
* @param obj The name representing the object whose method is to be invoked. The
* name is the one used to create bindings using the put method of
* ScriptEngine, the put method of an ENGINE_SCOPE
* Bindings,or the setAttribute method
* of ScriptContext. The identifier used in scripts may be a decorated form of the
* specified one.
*
* @param m The name of the method to invoke.
* @param args names of the arguments in the method call.
*
* @return The String used to invoke the method in the syntax of the scripting language.
*/
public String getMethodCallSyntax(String obj, String m, String... args);
/**
* Returns a String that can be used as a statement to display the specified String using
* the syntax of the supported scripting language. For instance, the implementaton for a Perl
* engine might be;
*
*
* public String getOutputStatement(String toDisplay) {
* return "print(" + toDisplay + ")";
* }
* *
{@code
* public String getProgram(String... statements) {
* $retval = "";
*
* }
* }
*
* @param statements The statements to be executed. May be return values of
* calls to the getMethodCallSyntax and getOutputStatement methods.
* @return The Program
*/
public String getProgram(String... statements);
/**
* Returns an instance of the ScriptEngine associated with this
* ScriptEngineFactory. A new ScriptEngine is generally
* returned, but implementations may pool, share or reuse engines.
*
* @return A new ScriptEngine instance.
*/
public ScriptEngine getScriptEngine();
}