org.activiti.engine.impl.scripting.ScriptingEngines Maven / Gradle / Ivy
The newest version!
/* Licensed 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.
*/
package org.activiti.engine.impl.scripting;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.script.Bindings;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineFactory;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import org.activiti.engine.ActivitiException;
import org.activiti.engine.delegate.VariableScope;
/**
*/
public class ScriptingEngines {
public static final String DEFAULT_SCRIPTING_LANGUAGE = "juel";
public static final String GROOVY_SCRIPTING_LANGUAGE = "groovy";
private final ScriptEngineManager scriptEngineManager;
protected ScriptBindingsFactory scriptBindingsFactory;
protected boolean cacheScriptingEngines = true;
protected Map cachedEngines;
public ScriptingEngines(ScriptBindingsFactory scriptBindingsFactory) {
this(new ScriptEngineManager());
this.scriptBindingsFactory = scriptBindingsFactory;
}
public ScriptingEngines(ScriptEngineManager scriptEngineManager) {
this.scriptEngineManager = scriptEngineManager;
cachedEngines = new HashMap();
}
public ScriptingEngines addScriptEngineFactory(ScriptEngineFactory scriptEngineFactory) {
scriptEngineManager.registerEngineName(scriptEngineFactory.getEngineName(), scriptEngineFactory);
return this;
}
public void setScriptEngineFactories(List scriptEngineFactories) {
if (scriptEngineFactories != null) {
for (ScriptEngineFactory scriptEngineFactory : scriptEngineFactories) {
scriptEngineManager.registerEngineName(scriptEngineFactory.getEngineName(), scriptEngineFactory);
}
}
}
public Object evaluate(String script, String language, VariableScope variableScope) {
return evaluate(script, language, createBindings(variableScope));
}
public Object evaluate(String script, String language, VariableScope variableScope, boolean storeScriptVariables) {
return evaluate(script, language, createBindings(variableScope, storeScriptVariables));
}
public void setCacheScriptingEngines(boolean cacheScriptingEngines) {
this.cacheScriptingEngines = cacheScriptingEngines;
}
public boolean isCacheScriptingEngines() {
return cacheScriptingEngines;
}
protected Object evaluate(String script, String language, Bindings bindings) {
ScriptEngine scriptEngine = getEngineByName(language);
try {
return scriptEngine.eval(script, bindings);
} catch (ScriptException e) {
throw new ActivitiException("problem evaluating script: " + e.getMessage(), e);
}
}
protected ScriptEngine getEngineByName(String language) {
ScriptEngine scriptEngine = null;
if (cacheScriptingEngines) {
scriptEngine = cachedEngines.get(language);
if (scriptEngine == null) {
scriptEngine = scriptEngineManager.getEngineByName(language);
if (scriptEngine != null) {
// ACT-1858: Special handling for groovy engine regarding GC
if (GROOVY_SCRIPTING_LANGUAGE.equals(language)) {
try {
scriptEngine.getContext().setAttribute("#jsr223.groovy.engine.keep.globals", "weak", ScriptContext.ENGINE_SCOPE);
} catch (Exception ignore) {
// ignore this, in case engine doesn't support the
// passed attribute
}
}
// Check if script-engine allows caching, using "THREADING"
// parameter as defined in spec
Object threadingParameter = scriptEngine.getFactory().getParameter("THREADING");
if (threadingParameter != null) {
// Add engine to cache as any non-null result from the
// threading-parameter indicates at least MT-access
cachedEngines.put(language, scriptEngine);
}
}
}
} else {
scriptEngine = scriptEngineManager.getEngineByName(language);
}
if (scriptEngine == null) {
throw new ActivitiException("Can't find scripting engine for '" + language + "'");
}
return scriptEngine;
}
/** override to build a spring aware ScriptingEngines */
protected Bindings createBindings(VariableScope variableScope) {
return scriptBindingsFactory.createBindings(variableScope);
}
/** override to build a spring aware ScriptingEngines */
protected Bindings createBindings(VariableScope variableScope, boolean storeScriptVariables) {
return scriptBindingsFactory.createBindings(variableScope, storeScriptVariables);
}
public ScriptBindingsFactory getScriptBindingsFactory() {
return scriptBindingsFactory;
}
public void setScriptBindingsFactory(ScriptBindingsFactory scriptBindingsFactory) {
this.scriptBindingsFactory = scriptBindingsFactory;
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy