INT-2177. Improved exception handling. Made ScriptExecutorFactory abstract

spring-integration-scripting/src/main/java/org/springframework/integration/scripting/ScriptingException.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2002-2011 the original author or authors.
+ * 
+ * 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.springframework.integration.scripting;
+
+import org.springframework.integration.MessagingException;
+
+/**
+ * @author David Turanski
+ * @since 2.1
+ */
+@SuppressWarnings("serial")
+
+public class ScriptingException extends MessagingException {
+	
+	public ScriptingException(String description) {
+		super(description);
+	}
+	
+	
+	public ScriptingException(String description, Throwable cause) {
+		super(description, cause);
+	}
+}

spring-integration-scripting/src/main/java/org/springframework/integration/scripting/jsr223/AbstractScriptExecutor.java

@@ -12,18 +12,17 @@
  */
 package org.springframework.integration.scripting.jsr223;
 
-import java.io.IOException;
 import java.util.Date;
 import java.util.Map;
 import java.util.Map.Entry;
 
 import javax.script.ScriptEngine;
 import javax.script.ScriptEngineManager;
-import javax.script.ScriptException;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.integration.scripting.ScriptExecutor;
+import org.springframework.integration.scripting.ScriptingException;
 import org.springframework.scripting.ScriptSource;
 import org.springframework.util.Assert;
 
@@ -46,14 +45,16 @@ abstract class AbstractScriptExecutor implements ScriptExecutor {
 		Assert.hasText(language, "language must not be empty");
 		this.language = language;
 		if (logger.isDebugEnabled()) {
-			logger.debug("using script engine : " + scriptEngineManager.getEngineByName(language).getFactory().getEngineName());
-			 for (String name:scriptEngineManager.getEngineByName(language).getFactory().getNames()){
-				 logger.debug("name=" + name);
-			 }
+			ScriptEngine scriptEngine = scriptEngineManager.getEngineByName(this.language);
+			if (scriptEngine == null) {
+				logger.error(invlalidLanguageMessage(this.language));
+			}
+			else {
+				logger.debug("using script engine : " + scriptEngine.getFactory().getEngineName());
+			}
 		}
 	}
 
-
 	public Object executeScript(ScriptSource scriptSource) {
 		return this.executeScript(scriptSource, null);
 	}
@@ -61,6 +62,11 @@ abstract class AbstractScriptExecutor implements ScriptExecutor {
 	public Object executeScript(ScriptSource scriptSource, Map<String, Object> variables) {
 		Object result = null;
 		ScriptEngine scriptEngine = this.scriptEngineManager.getEngineByName(this.language);
+
+		if (scriptEngine == null) {
+			throw new ScriptingException(invlalidLanguageMessage(this.language));
+		}
+
 		try {
 			if (variables != null) {
 				for (Entry<String, Object> entry : variables.entrySet()) {
@@ -72,25 +78,23 @@ abstract class AbstractScriptExecutor implements ScriptExecutor {
 			if (logger.isDebugEnabled()) {
 				logger.debug("executing script: " + script);
 			}
-			
+
 			result = scriptEngine.eval(script);
-			
+
 			result = postProcess(result, scriptEngine, script);
-			
+
 			if (logger.isDebugEnabled()) {
 				logger.debug("script executed in " + (new Date().getTime() - start.getTime()) + " ms");
 			}
 		}
-		catch (IOException e) {
-			throw new RuntimeException(e);
-		}
-		catch (ScriptException e) {
-			throw new RuntimeException(e);
+
+		catch (Exception e) {
+			throw new ScriptingException(e.getMessage(), e);
 		}
+
 		return result;
 	}
 
-
 	/**
 	 * Subclasses may implement this to provide any special handling required
 	 * @param result
@@ -100,4 +104,10 @@ abstract class AbstractScriptExecutor implements ScriptExecutor {
 	 */
 	protected abstract Object postProcess(Object result, ScriptEngine scriptEngine, String script);
 
+	private static String invlalidLanguageMessage(String language) {
+		return new StringBuilder().append(ScriptEngineManager.class.getName())
+				.append(" is unable to create a script engine for language '").append(language).append("'.\n")
+				.append("This may be due to a missing language implementation or an invalid language name.").toString();
+	}
+
 }

spring-integration-scripting/src/main/java/org/springframework/integration/scripting/jsr223/ScriptExecutorFactory.java

@@ -18,9 +18,8 @@ import org.springframework.integration.scripting.ScriptExecutor;
  * @author David Turanski
  * @since 2.1
  */
-public class ScriptExecutorFactory {
+public abstract class ScriptExecutorFactory {
 	
-	private ScriptExecutorFactory(){};
 	public static ScriptExecutor getScriptExecutor(String language) {
 		if (language.equalsIgnoreCase("python") || language.equalsIgnoreCase("jython")){
 			return new PythonScriptExecutor();