src/main/java/org/apache/sling/hc/support/impl/ScriptedHealthCheck.java - sling-org-apache-sling-hc-support - Git at Google

 /*
  * 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 SF 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.
  */
 package org.apache.sling.hc.support.impl;

 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.StringWriter;
 import java.lang.reflect.Array;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;

 import javax.jcr.Session;
 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 javax.script.SimpleBindings;
 import javax.script.SimpleScriptContext;

 import org.apache.commons.lang3.StringUtils;
 import org.apache.felix.hc.api.FormattingResultLog;
 import org.apache.felix.hc.api.HealthCheck;
 import org.apache.felix.hc.api.Result;
 import org.apache.felix.hc.api.ResultLog;
 import org.apache.sling.api.resource.LoginException;
 import org.apache.sling.api.resource.Resource;
 import org.apache.sling.api.resource.ResourceResolver;
 import org.apache.sling.api.resource.ResourceResolverFactory;
 import org.osgi.framework.BundleContext;
 import org.osgi.framework.InvalidSyntaxException;
 import org.osgi.framework.ServiceReference;
 import org.osgi.service.component.annotations.Activate;
 import org.osgi.service.component.annotations.Component;
 import org.osgi.service.component.annotations.ConfigurationPolicy;
 import org.osgi.service.component.annotations.Reference;
 import org.osgi.service.metatype.annotations.AttributeDefinition;
 import org.osgi.service.metatype.annotations.Designate;
 import org.osgi.service.metatype.annotations.ObjectClassDefinition;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 /**
  * {@link HealthCheck} that runs an arbitrary script.
  *
  * @deprecated for SLING-11445 -  use the equivalent functionality from the org.apache.felix.healthcheck.generalchecks bundle instead
  */
 @Component(service = HealthCheck.class, name = "org.apache.sling.hc.support.ScriptedHealthCheck", configurationPolicy = ConfigurationPolicy.REQUIRE)
 @Designate(ocd = ScriptedHealthCheck.Config.class, factory = true)
 @Deprecated
 public class ScriptedHealthCheck implements HealthCheck {

     private static final Logger LOG = LoggerFactory.getLogger(ScriptedHealthCheck.class);

     public static final String HC_LABEL = "Health Check: Sling Script (deprecated)";

     public static final String JCR_FILE_URL_PREFIX = "jcr:";
     private static final String JCR_CONTENT = "/jcr:content";

     @ObjectClassDefinition(name = HC_LABEL, description = "NOTE: This Sling pendant of org.apache.felix.hc.generalchecks.ScriptedHealthCheck allows to use scriptUrls with prefix 'jcr:' and has the additional bindings 'resourceResolver' and 'session'. "
             + "Runs an arbitrary script in given scriping language (via javax.script). "
             + "The script has the following default bindings available: 'log', 'scriptHelper', 'bundleContext', 'resourceResolver' and 'session'. "
             + "'log' is an instance of org.apache.felix.hc.api.FormattingResultLog and is used to define the result of the HC. "
             + "'scriptHelper.getService(classObj)' can be used as shortcut to retrieve a service."
             + "'scriptHelper.getServices(classObj, filter)' used to retrieve multiple services for a class using given filter. "
             + "For all services retrieved via scriptHelper, unget() is called automatically at the end of the script execution."
             + "'bundleContext' is available for advanced use cases. The script does not need to return any value, but if it does and it is "
             + "a org.apache.felix.hc.api.Result, that result and entries in 'log' are combined then).")
     @interface Config {

         @AttributeDefinition(name = "Name", description = "Name of this health check.")
         String hc_name() default "Scripted Health Check"; // NOSONAR

         @AttributeDefinition(name = "Tags", description = "List of tags for this health check, used to select subsets of health checks for execution e.g. by a composite health check.")
         String[] hc_tags() default {}; // NOSONAR

         @AttributeDefinition(name = "Language", description = "The language the script is written in. To use e.g. 'groovy', ensure osgi bundle 'groovy-jsr223' is available.")
         String language() default "groovy";

         @AttributeDefinition(name = "Script", description = "The script itself (either use 'script' or 'scriptUrl').")
         String script() default "log.info('ok'); log.warn('not so good'); log.critical('bad') // minimal example";

         @AttributeDefinition(name = "Script Url", description = "Url to the script to be used as alternative source (either use 'script' or 'scriptUrl').")
         String scriptUrl() default "";

         @AttributeDefinition
         String webconsole_configurationFactory_nameHint() default "Scripted HC (deprecated): {hc.name} (tags: {hc.tags}) {scriptUrl} language: {language}"; // NOSONAR
     }

     private String language;
     private String script;
     private String scriptUrl;

     private BundleContext bundleContext;

     @Reference
     private ScriptEngineManager scriptEngineManager;

     private ScriptHelper scriptHelper = new ScriptHelper();

     @Reference
     private ResourceResolverFactory resourceResolverFactory;

     @Activate
     protected void activate(BundleContext context, Config config) {
         this.bundleContext = context;
         this.language = config.language().toLowerCase();
         this.script = config.script();
         this.scriptUrl = config.scriptUrl();

         if (StringUtils.isNotBlank(script) && StringUtils.isNotBlank(scriptUrl)) {
             LOG.info("Both 'script' and 'scriptUrl' (={}) are configured, ignoring 'scriptUrl'", scriptUrl);
             scriptUrl = null;
         }

         LOG.info("Activated Scripted HC {} with {}", config.hc_name(),
                 (StringUtils.isNotBlank(script) ? "script " + script : "script url " + scriptUrl));

         LOG.warn("This is deprecated. Please use the use the equivalent functionality from the org.apache.felix.healthcheck.generalchecks bundle instead.");
     }

     @Override
     public Result execute() {
         FormattingResultLog log = new FormattingResultLog();

         ResourceResolver resourceResolver = null;
         try {
             resourceResolver = resourceResolverFactory.getServiceResourceResolver(null);

             boolean urlIsUsed = StringUtils.isBlank(script);
             String scriptToExecute;
             if (urlIsUsed) {
                 if (scriptUrl.startsWith(JCR_FILE_URL_PREFIX)) {
                     String jcrPath = StringUtils.substringAfter(scriptUrl, JCR_FILE_URL_PREFIX);
                     scriptToExecute = getScriptFromRepository(resourceResolver, jcrPath);
                 } else {
                     scriptToExecute = scriptHelper.getFileContents(scriptUrl);
                 }
             } else {
                 scriptToExecute = script;
             }

             log.info("Executing script {} ({} lines)...", (urlIsUsed ? scriptUrl : " as configured"), scriptToExecute.split("\n").length);

             try {
                 ScriptEngine scriptEngine = getScriptEngine(language);

                 Map<String, Object> additionalBindings = new HashMap<>();
                 additionalBindings.put("resourceResolver", resourceResolver);
                 additionalBindings.put("session", resourceResolver.adaptTo(Session.class));
                 scriptHelper.evalScript(bundleContext, scriptEngine, scriptToExecute, log, additionalBindings, true);
             } catch (Exception e) {
                 log.healthCheckError("Exception while executing script: " + e, e);
             }

             return new Result(log);
         } catch (LoginException e) {
             throw new IllegalStateException("Could not get resource resolver: " + e, e);
         } finally {
             if (resourceResolver != null) {
                 resourceResolver.close();
             }
         }
     }

     private String factoriesToString(List<ScriptEngineFactory> engineFactories) {
         List<String> factoryArr = new ArrayList<>();
         for (ScriptEngineFactory ef : engineFactories) {
             factoryArr.add(ef.getEngineName() + " (" + StringUtils.join(ef.getExtensions(), ",") + ")");
         }
         return StringUtils.join(factoryArr, ", ");
     }

     private ScriptEngine getScriptEngine(String language) {
         ScriptEngine scriptEngine = scriptEngineManager.getEngineByExtension(language);
         if (scriptEngine == null) {
             try {
                 scriptEngine = scriptHelper.getScriptEngine(scriptEngineManager, language);
             } catch (IllegalArgumentException e) {
                 throw new IllegalStateException("Could not get script engine for " + language + " from available factories: "
                         + factoriesToString(scriptEngineManager.getEngineFactories()) + ") nor from regular bundles: " + e.getMessage());
             }
         }
         return scriptEngine;
     }

     private String getScriptFromRepository(ResourceResolver resourceResolver, String jcrPath) {
         String fileContent;
         try {
             Resource dataResource = resourceResolver.getResource(jcrPath + JCR_CONTENT);
             if (dataResource == null) {
                 throw new IllegalArgumentException("Could not load script from path " + jcrPath);
             } else {
                 try (InputStream is = dataResource.adaptTo(InputStream.class);
                         ByteArrayOutputStream result = new ByteArrayOutputStream();) {
                     byte[] buffer = new byte[1024];
                     int length;
                     while ((length = is.read(buffer)) != -1) {
                         result.write(buffer, 0, length);
                     }
                     fileContent = result.toString(StandardCharsets.UTF_8.name());
                 }
             }
         } catch (IOException e) {
             throw new IllegalStateException("Could not load script from path " + jcrPath + ": " + e, e);
         }
         return fileContent;
     }

     /**
      * Copied and adapted from org.apache.felix.hc.generalchecks.util.ScriptHelper
      */
     private static class ScriptHelper {

         public String getFileContents(String url) {
             String content;
             try {
                 content = Files.readAllLines(Paths.get(new URI(url))).stream().collect(Collectors.joining("\n"));
                 return content;
             }catch(IOException | URISyntaxException e) {
                 throw new IllegalArgumentException("Could not read file URL "+url+": "+e, e);
             }
         }

         public ScriptEngine getScriptEngine(ScriptEngineManager scriptEngineManager, String language) {
             List<ScriptEngineFactory> engineFactories = scriptEngineManager.getEngineFactories();
             ScriptEngine scriptEngine = engineFactories.stream()
                 .filter(s -> language.equalsIgnoreCase(s.getLanguageName()))
                 .findFirst()
                 .map(ScriptEngineFactory::getScriptEngine)
                 .orElse(null);
             if(scriptEngine == null) {
                 Set<String> availableLanguages = engineFactories.stream()
                     .map(ScriptEngineFactory::getLanguageName)
                     .collect(Collectors.toSet());
                 throw new IllegalArgumentException("No ScriptEngineFactory found for language " + language + " (available languages: " + availableLanguages + ")");
             }
             return scriptEngine;
         }

         public Object evalScript(BundleContext bundleContext, ScriptEngine scriptEngine, String scriptToExecute, FormattingResultLog log, Map<String,Object> additionalBindings, boolean logScriptResult) throws ScriptException, IOException {

             final Bindings bindings = new SimpleBindings();
             final ScriptHelperBinding scriptHelper = new ScriptHelperBinding(bundleContext);

             StringWriter stdout = new StringWriter();
             StringWriter stderr = new StringWriter();

             bindings.put("scriptHelper", scriptHelper);
             bindings.put("osgi", scriptHelper); // also register script helper like in web console script console
             bindings.put("log", log);
             bindings.put("bundleContext", bundleContext);
             if (additionalBindings != null) {
                 for (Map.Entry<String, Object> additionalBinding : additionalBindings.entrySet()) {
                     bindings.put(additionalBinding.getKey(), additionalBinding.getValue());
                 }
             }

             SimpleScriptContext scriptContext = new SimpleScriptContext();
             scriptContext.setBindings(bindings, ScriptContext.ENGINE_SCOPE);
             scriptContext.setWriter(stdout);
             scriptContext.setErrorWriter(stderr);

             try {
                 log.debug(scriptToExecute);
                 Object scriptResult = scriptEngine.eval(scriptToExecute, scriptContext);
                 appendStreamsToResult(log, stdout, stderr, scriptContext);

                 if(scriptResult instanceof Result) {
                     Result result = (Result) scriptResult;
                     for(ResultLog.Entry entry: result) {
                         log.add(entry);
                     }
                 } else if(scriptResult != null && logScriptResult){
                     log.info("Script result: {}", scriptResult);
                 }

                 return scriptResult;
             } finally  {
                 scriptHelper.ungetServices();
             }
         }

         private void appendStreamsToResult(FormattingResultLog log, StringWriter stdout, StringWriter stderr, SimpleScriptContext scriptContext)
                 throws IOException {
             scriptContext.getWriter().flush();
             String stdoutStr = stdout.toString();
             if(StringUtils.isNotBlank(stdoutStr)) {
                 log.info("stdout of script: {}", stdoutStr);
             }

             scriptContext.getErrorWriter().flush();
             String stderrStr = stderr.toString();
             if(StringUtils.isNotBlank(stderrStr)) {
                 log.critical("stderr of script: {}", stderrStr);
             }
         }

         // Script Helper for OSGi available as binding 'scriptHelper'
         class ScriptHelperBinding {

             private final BundleContext bundleContext;
             private List<ServiceReference<?>> references;
             private Map<String, Object> services;

             public ScriptHelperBinding(BundleContext bundleContext) {
                 this.bundleContext = bundleContext;
             }

             @SuppressWarnings({ "unchecked", "unused" })
             public <T> T getService(Class<T> type) {
                 T service = (this.services == null ? null  : (T) this.services.get(type.getName()));
                 if (service == null) {
                     final ServiceReference<?> ref = this.bundleContext.getServiceReference(type.getName());
                     if (ref != null) {
                         service = (T) this.bundleContext.getService(ref);
                         if (service != null) {
                             if (this.services == null) {
                                 this.services = new HashMap<>();
                             }
                             if (this.references == null) {
                                 this.references = new ArrayList<>();
                             }
                             this.references.add(ref);
                             this.services.put(type.getName(), service);
                         }
                     }
                 }
                 return service;
             }

             @SuppressWarnings("unused")
             public <T> T[] getServices(Class<T> serviceType,  String filter) throws InvalidSyntaxException {
                 final ServiceReference<?>[] refs = this.bundleContext.getServiceReferences(serviceType.getName(), filter);
                 T[] result = null;
                 if (refs != null) {
                     final List<T> objects = new ArrayList<>();
                     for (int i = 0; i < refs.length; i++) {
                         @SuppressWarnings("unchecked")
                         final T service = (T) this.bundleContext.getService(refs[i]);
                         if (service != null) {
                             if (this.references == null) {
                                 this.references = new ArrayList<>();
                             }
                             this.references.add(refs[i]);
                             objects.add(service);
                         }
                     }
                     if (!objects.isEmpty()) {
                         @SuppressWarnings("unchecked")
                         T[] srv = (T[]) Array.newInstance(serviceType,  objects.size());
                         result = objects.toArray(srv);
                     }
                 }
                 return result;
             }

             public void ungetServices() {
                 if (this.references != null) {
                     final Iterator<ServiceReference<?>> i = this.references.iterator();
                     while (i.hasNext()) {
                         final ServiceReference<?> ref = i.next();
                         this.bundleContext.ungetService(ref);
                     }
                     this.references.clear();
                 }
                 if (this.services != null) {
                     this.services.clear();
                 }
             }
         }

     }

 }
	/*
	* 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 SF 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.
	*/
	package org.apache.sling.hc.support.impl;

	import java.io.ByteArrayOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.StringWriter;
	import java.lang.reflect.Array;
	import java.net.URI;
	import java.net.URISyntaxException;
	import java.nio.charset.StandardCharsets;
	import java.nio.file.Files;
	import java.nio.file.Paths;
	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;
	import java.util.stream.Collectors;

	import javax.jcr.Session;
	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 javax.script.SimpleBindings;
	import javax.script.SimpleScriptContext;

	import org.apache.commons.lang3.StringUtils;
	import org.apache.felix.hc.api.FormattingResultLog;
	import org.apache.felix.hc.api.HealthCheck;
	import org.apache.felix.hc.api.Result;
	import org.apache.felix.hc.api.ResultLog;
	import org.apache.sling.api.resource.LoginException;
	import org.apache.sling.api.resource.Resource;
	import org.apache.sling.api.resource.ResourceResolver;
	import org.apache.sling.api.resource.ResourceResolverFactory;
	import org.osgi.framework.BundleContext;
	import org.osgi.framework.InvalidSyntaxException;
	import org.osgi.framework.ServiceReference;
	import org.osgi.service.component.annotations.Activate;
	import org.osgi.service.component.annotations.Component;
	import org.osgi.service.component.annotations.ConfigurationPolicy;
	import org.osgi.service.component.annotations.Reference;
	import org.osgi.service.metatype.annotations.AttributeDefinition;
	import org.osgi.service.metatype.annotations.Designate;
	import org.osgi.service.metatype.annotations.ObjectClassDefinition;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	/**
	* {@link HealthCheck} that runs an arbitrary script.
	*
	* @deprecated for SLING-11445 - use the equivalent functionality from the org.apache.felix.healthcheck.generalchecks bundle instead
	*/
	@Component(service = HealthCheck.class, name = "org.apache.sling.hc.support.ScriptedHealthCheck", configurationPolicy = ConfigurationPolicy.REQUIRE)
	@Designate(ocd = ScriptedHealthCheck.Config.class, factory = true)
	@Deprecated
	public class ScriptedHealthCheck implements HealthCheck {

	private static final Logger LOG = LoggerFactory.getLogger(ScriptedHealthCheck.class);

	public static final String HC_LABEL = "Health Check: Sling Script (deprecated)";

	public static final String JCR_FILE_URL_PREFIX = "jcr:";
	private static final String JCR_CONTENT = "/jcr:content";

	@ObjectClassDefinition(name = HC_LABEL, description = "NOTE: This Sling pendant of org.apache.felix.hc.generalchecks.ScriptedHealthCheck allows to use scriptUrls with prefix 'jcr:' and has the additional bindings 'resourceResolver' and 'session'. "
	+ "Runs an arbitrary script in given scriping language (via javax.script). "
	+ "The script has the following default bindings available: 'log', 'scriptHelper', 'bundleContext', 'resourceResolver' and 'session'. "
	+ "'log' is an instance of org.apache.felix.hc.api.FormattingResultLog and is used to define the result of the HC. "
	+ "'scriptHelper.getService(classObj)' can be used as shortcut to retrieve a service."
	+ "'scriptHelper.getServices(classObj, filter)' used to retrieve multiple services for a class using given filter. "
	+ "For all services retrieved via scriptHelper, unget() is called automatically at the end of the script execution."
	+ "'bundleContext' is available for advanced use cases. The script does not need to return any value, but if it does and it is "
	+ "a org.apache.felix.hc.api.Result, that result and entries in 'log' are combined then).")
	@interface Config {

	@AttributeDefinition(name = "Name", description = "Name of this health check.")
	String hc_name() default "Scripted Health Check"; // NOSONAR

	@AttributeDefinition(name = "Tags", description = "List of tags for this health check, used to select subsets of health checks for execution e.g. by a composite health check.")
	String[] hc_tags() default {}; // NOSONAR

	@AttributeDefinition(name = "Language", description = "The language the script is written in. To use e.g. 'groovy', ensure osgi bundle 'groovy-jsr223' is available.")
	String language() default "groovy";

	@AttributeDefinition(name = "Script", description = "The script itself (either use 'script' or 'scriptUrl').")
	String script() default "log.info('ok'); log.warn('not so good'); log.critical('bad') // minimal example";

	@AttributeDefinition(name = "Script Url", description = "Url to the script to be used as alternative source (either use 'script' or 'scriptUrl').")
	String scriptUrl() default "";

	@AttributeDefinition
	String webconsole_configurationFactory_nameHint() default "Scripted HC (deprecated): {hc.name} (tags: {hc.tags}) {scriptUrl} language: {language}"; // NOSONAR
	}

	private String language;
	private String script;
	private String scriptUrl;

	private BundleContext bundleContext;

	@Reference
	private ScriptEngineManager scriptEngineManager;

	private ScriptHelper scriptHelper = new ScriptHelper();

	@Reference
	private ResourceResolverFactory resourceResolverFactory;

	@Activate
	protected void activate(BundleContext context, Config config) {
	this.bundleContext = context;
	this.language = config.language().toLowerCase();
	this.script = config.script();
	this.scriptUrl = config.scriptUrl();

	if (StringUtils.isNotBlank(script) && StringUtils.isNotBlank(scriptUrl)) {
	LOG.info("Both 'script' and 'scriptUrl' (={}) are configured, ignoring 'scriptUrl'", scriptUrl);
	scriptUrl = null;
	}

	LOG.info("Activated Scripted HC {} with {}", config.hc_name(),
	(StringUtils.isNotBlank(script) ? "script " + script : "script url " + scriptUrl));

	LOG.warn("This is deprecated. Please use the use the equivalent functionality from the org.apache.felix.healthcheck.generalchecks bundle instead.");
	}

	@Override
	public Result execute() {
	FormattingResultLog log = new FormattingResultLog();

	ResourceResolver resourceResolver = null;
	try {
	resourceResolver = resourceResolverFactory.getServiceResourceResolver(null);

	boolean urlIsUsed = StringUtils.isBlank(script);
	String scriptToExecute;
	if (urlIsUsed) {
	if (scriptUrl.startsWith(JCR_FILE_URL_PREFIX)) {
	String jcrPath = StringUtils.substringAfter(scriptUrl, JCR_FILE_URL_PREFIX);
	scriptToExecute = getScriptFromRepository(resourceResolver, jcrPath);
	} else {
	scriptToExecute = scriptHelper.getFileContents(scriptUrl);
	}
	} else {
	scriptToExecute = script;
	}

	log.info("Executing script {} ({} lines)...", (urlIsUsed ? scriptUrl : " as configured"), scriptToExecute.split("\n").length);

	try {
	ScriptEngine scriptEngine = getScriptEngine(language);

	Map<String, Object> additionalBindings = new HashMap<>();
	additionalBindings.put("resourceResolver", resourceResolver);
	additionalBindings.put("session", resourceResolver.adaptTo(Session.class));
	scriptHelper.evalScript(bundleContext, scriptEngine, scriptToExecute, log, additionalBindings, true);
	} catch (Exception e) {
	log.healthCheckError("Exception while executing script: " + e, e);
	}

	return new Result(log);
	} catch (LoginException e) {
	throw new IllegalStateException("Could not get resource resolver: " + e, e);
	} finally {
	if (resourceResolver != null) {
	resourceResolver.close();
	}
	}
	}

	private String factoriesToString(List<ScriptEngineFactory> engineFactories) {
	List<String> factoryArr = new ArrayList<>();
	for (ScriptEngineFactory ef : engineFactories) {
	factoryArr.add(ef.getEngineName() + " (" + StringUtils.join(ef.getExtensions(), ",") + ")");
	}
	return StringUtils.join(factoryArr, ", ");
	}

	private ScriptEngine getScriptEngine(String language) {
	ScriptEngine scriptEngine = scriptEngineManager.getEngineByExtension(language);
	if (scriptEngine == null) {
	try {
	scriptEngine = scriptHelper.getScriptEngine(scriptEngineManager, language);
	} catch (IllegalArgumentException e) {
	throw new IllegalStateException("Could not get script engine for " + language + " from available factories: "
	+ factoriesToString(scriptEngineManager.getEngineFactories()) + ") nor from regular bundles: " + e.getMessage());
	}
	}
	return scriptEngine;
	}

	private String getScriptFromRepository(ResourceResolver resourceResolver, String jcrPath) {
	String fileContent;
	try {
	Resource dataResource = resourceResolver.getResource(jcrPath + JCR_CONTENT);
	if (dataResource == null) {
	throw new IllegalArgumentException("Could not load script from path " + jcrPath);
	} else {
	try (InputStream is = dataResource.adaptTo(InputStream.class);
	ByteArrayOutputStream result = new ByteArrayOutputStream();) {
	byte[] buffer = new byte[1024];
	int length;
	while ((length = is.read(buffer)) != -1) {
	result.write(buffer, 0, length);
	}
	fileContent = result.toString(StandardCharsets.UTF_8.name());
	}
	}
	} catch (IOException e) {
	throw new IllegalStateException("Could not load script from path " + jcrPath + ": " + e, e);
	}
	return fileContent;
	}

	/**
	* Copied and adapted from org.apache.felix.hc.generalchecks.util.ScriptHelper
	*/
	private static class ScriptHelper {

	public String getFileContents(String url) {
	String content;
	try {
	content = Files.readAllLines(Paths.get(new URI(url))).stream().collect(Collectors.joining("\n"));
	return content;
	}catch(IOException \| URISyntaxException e) {
	throw new IllegalArgumentException("Could not read file URL "+url+": "+e, e);
	}
	}

	public ScriptEngine getScriptEngine(ScriptEngineManager scriptEngineManager, String language) {
	List<ScriptEngineFactory> engineFactories = scriptEngineManager.getEngineFactories();
	ScriptEngine scriptEngine = engineFactories.stream()
	.filter(s -> language.equalsIgnoreCase(s.getLanguageName()))
	.findFirst()
	.map(ScriptEngineFactory::getScriptEngine)
	.orElse(null);
	if(scriptEngine == null) {
	Set<String> availableLanguages = engineFactories.stream()
	.map(ScriptEngineFactory::getLanguageName)
	.collect(Collectors.toSet());
	throw new IllegalArgumentException("No ScriptEngineFactory found for language " + language + " (available languages: " + availableLanguages + ")");
	}
	return scriptEngine;
	}

	public Object evalScript(BundleContext bundleContext, ScriptEngine scriptEngine, String scriptToExecute, FormattingResultLog log, Map<String,Object> additionalBindings, boolean logScriptResult) throws ScriptException, IOException {

	final Bindings bindings = new SimpleBindings();
	final ScriptHelperBinding scriptHelper = new ScriptHelperBinding(bundleContext);

	StringWriter stdout = new StringWriter();
	StringWriter stderr = new StringWriter();

	bindings.put("scriptHelper", scriptHelper);
	bindings.put("osgi", scriptHelper); // also register script helper like in web console script console
	bindings.put("log", log);
	bindings.put("bundleContext", bundleContext);
	if (additionalBindings != null) {
	for (Map.Entry<String, Object> additionalBinding : additionalBindings.entrySet()) {
	bindings.put(additionalBinding.getKey(), additionalBinding.getValue());
	}
	}

	SimpleScriptContext scriptContext = new SimpleScriptContext();
	scriptContext.setBindings(bindings, ScriptContext.ENGINE_SCOPE);
	scriptContext.setWriter(stdout);
	scriptContext.setErrorWriter(stderr);

	try {
	log.debug(scriptToExecute);
	Object scriptResult = scriptEngine.eval(scriptToExecute, scriptContext);
	appendStreamsToResult(log, stdout, stderr, scriptContext);

	if(scriptResult instanceof Result) {
	Result result = (Result) scriptResult;
	for(ResultLog.Entry entry: result) {
	log.add(entry);
	}
	} else if(scriptResult != null && logScriptResult){
	log.info("Script result: {}", scriptResult);
	}

	return scriptResult;
	} finally {
	scriptHelper.ungetServices();
	}
	}

	private void appendStreamsToResult(FormattingResultLog log, StringWriter stdout, StringWriter stderr, SimpleScriptContext scriptContext)
	throws IOException {
	scriptContext.getWriter().flush();
	String stdoutStr = stdout.toString();
	if(StringUtils.isNotBlank(stdoutStr)) {
	log.info("stdout of script: {}", stdoutStr);
	}

	scriptContext.getErrorWriter().flush();
	String stderrStr = stderr.toString();
	if(StringUtils.isNotBlank(stderrStr)) {
	log.critical("stderr of script: {}", stderrStr);
	}
	}

	// Script Helper for OSGi available as binding 'scriptHelper'
	class ScriptHelperBinding {

	private final BundleContext bundleContext;
	private List<ServiceReference<?>> references;
	private Map<String, Object> services;

	public ScriptHelperBinding(BundleContext bundleContext) {
	this.bundleContext = bundleContext;
	}

	@SuppressWarnings({ "unchecked", "unused" })
	public <T> T getService(Class<T> type) {
	T service = (this.services == null ? null : (T) this.services.get(type.getName()));
	if (service == null) {
	final ServiceReference<?> ref = this.bundleContext.getServiceReference(type.getName());
	if (ref != null) {
	service = (T) this.bundleContext.getService(ref);
	if (service != null) {
	if (this.services == null) {
	this.services = new HashMap<>();
	}
	if (this.references == null) {
	this.references = new ArrayList<>();
	}
	this.references.add(ref);
	this.services.put(type.getName(), service);
	}
	}
	}
	return service;
	}

	@SuppressWarnings("unused")
	public <T> T[] getServices(Class<T> serviceType, String filter) throws InvalidSyntaxException {
	final ServiceReference<?>[] refs = this.bundleContext.getServiceReferences(serviceType.getName(), filter);
	T[] result = null;
	if (refs != null) {
	final List<T> objects = new ArrayList<>();
	for (int i = 0; i < refs.length; i++) {
	@SuppressWarnings("unchecked")
	final T service = (T) this.bundleContext.getService(refs[i]);
	if (service != null) {
	if (this.references == null) {
	this.references = new ArrayList<>();
	}
	this.references.add(refs[i]);
	objects.add(service);
	}
	}
	if (!objects.isEmpty()) {
	@SuppressWarnings("unchecked")
	T[] srv = (T[]) Array.newInstance(serviceType, objects.size());
	result = objects.toArray(srv);
	}
	}
	return result;
	}

	public void ungetServices() {
	if (this.references != null) {
	final Iterator<ServiceReference<?>> i = this.references.iterator();
	while (i.hasNext()) {
	final ServiceReference<?> ref = i.next();
	this.bundleContext.ungetService(ref);
	}
	this.references.clear();
	}
	if (this.services != null) {
	this.services.clear();
	}
	}
	}

	}

	}