content: /*
   * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
   *
   * 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<String, ScriptEngine> cachedEngines;
  
      public ScriptingEngines(ScriptBindingsFactory scriptBindingsFactory) {
          this(new ScriptEngineManager());
          this.scriptBindingsFactory = scriptBindingsFactory;
      }
  
      public ScriptingEngines(ScriptEngineManager scriptEngineManager) {
          this.scriptEngineManager = scriptEngineManager;
          cachedEngines = new HashMap<String, ScriptEngine>();
      }
  
      public ScriptingEngines addScriptEngineFactory(ScriptEngineFactory scriptEngineFactory) {
          scriptEngineManager.registerEngineName(scriptEngineFactory.getEngineName(), scriptEngineFactory);
          return this;
      }
  
      public void setScriptEngineFactories(List<ScriptEngineFactory> 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;
      }
  }
  