package org.apache.maven.plugins.scripting; | |
/* | |
* Licensed to the Apache Software Foundation (ASF) under one | |
* or more contributor license agreements. See the NOTICE file | |
* distributed with this work for additional information | |
* regarding copyright ownership. The ASF licenses this file | |
* to you under the Apache License, Version 2.0 (the | |
* "License"); you may not use this file except in compliance | |
* with the License. You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, | |
* software distributed under the License is distributed on an | |
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
* KIND, either express or implied. See the License for the | |
* specific language governing permissions and limitations | |
* under the License. | |
*/ | |
import javax.script.Bindings; | |
import javax.script.ScriptContext; | |
import javax.script.ScriptEngine; | |
import javax.script.ScriptEngineManager; | |
import javax.script.ScriptException; | |
/** | |
* Evaluates a script in the appropriate context and return its possibly null result | |
* @author Rusi Popov | |
*/ | |
abstract class AbstractScriptEvaluator | |
{ | |
/** | |
* @param bindings not null bindings to provide to the script to execute | |
* @return the possibly null result the script produced | |
* @throws UnsupportedScriptEngineException when the engine is not configured correctly | |
* @throws ScriptException if an error occurs in script. | |
*/ | |
public final Object eval( Bindings bindings ) throws ScriptException, UnsupportedScriptEngineException | |
{ | |
ScriptEngineManager manager = new ScriptEngineManager(); | |
ScriptEngine engine = getEngine( manager ); | |
ScriptContext context = engine.getContext(); | |
context.setBindings( bindings, ScriptContext.GLOBAL_SCOPE ); | |
return eval( engine, context ); | |
} | |
/** | |
* AbstractScriptEvaluator the script | |
* @param engine not null | |
* @param context not null, initialized | |
* @return possibly null result of the script | |
* @throws ScriptException if an error occurs in script. | |
*/ | |
protected abstract Object eval( ScriptEngine engine, ScriptContext context ) throws ScriptException; | |
/** | |
* @param manager not null | |
* @return non-null engine to execute the script | |
* @throws UnsupportedScriptEngineException when no engine could be identified | |
*/ | |
protected abstract ScriptEngine getEngine( ScriptEngineManager manager ) | |
throws UnsupportedScriptEngineException; | |
} |