From abf508cc6bc91f74c9d4db4f572b0f8179a1d87d Mon Sep 17 00:00:00 2001
From: Robert von Burg <eitch@eitchnet.ch>
Date: Mon, 18 Jun 2018 18:46:23 +0200
Subject: [PATCH] [Minor] Throw exception if policy is missing proper
 constructor

---
 .../strolch/policy/DefaultPolicyHandler.java  | 47 ++++++++++---------
 1 file changed, 26 insertions(+), 21 deletions(-)

diff --git a/li.strolch.agent/src/main/java/li/strolch/policy/DefaultPolicyHandler.java b/li.strolch.agent/src/main/java/li/strolch/policy/DefaultPolicyHandler.java
index 187939906..a9613d094 100644
--- a/li.strolch.agent/src/main/java/li/strolch/policy/DefaultPolicyHandler.java
+++ b/li.strolch.agent/src/main/java/li/strolch/policy/DefaultPolicyHandler.java
@@ -1,12 +1,12 @@
 /*
  * Copyright 2015 Robert von Burg <eitch@eitchnet.ch>
- * 
+ *
  * 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.
@@ -37,19 +37,19 @@ import li.strolch.utils.helper.XmlHelper;
 
 /**
  * <p>
- * This is the default Strolch {@link PolicyHandler} which implements {@link PolicyDefVisitor}. This
- * {@link PolicyHandler} parses a policy configuration file to handle the look-up of {@link KeyPolicyDef}
+ * This is the default Strolch {@link PolicyHandler} which implements {@link PolicyDefVisitor}. This {@link
+ * PolicyHandler} parses a policy configuration file to handle the look-up of {@link KeyPolicyDef}
  * </p>
- * 
+ *
  * This {@link StrolchComponent} uses two configuration properties:
  * <ul>
- * <li>{@link #PROP_READ_POLICY_FILE} - Default is false. If false then no configuration file is read. Useful if all
- * policy definitions are {@link JavaPolicyDef}</li>
- * <li>{@link #PROP_POLICY_CONFIG} - Default is {@link #DEF_STROLCH_POLICIES_XML}. If {@link #PROP_READ_POLICY_FILE} is
- * true, then this property is used to determine which configuration file to parse for the policy key mappings for
- * {@link KeyPolicyDef}</li>
+ * <li>{@link #PROP_READ_POLICY_FILE} - Default is false. If false then no configuration file is
+ * read. Useful if all policy definitions are {@link JavaPolicyDef}</li>
+ * <li>{@link #PROP_POLICY_CONFIG} - Default is {@link #DEF_STROLCH_POLICIES_XML}. If {@link
+ * #PROP_READ_POLICY_FILE} is true, then this property is used to determine which configuration file to parse for the
+ * policy key mappings for {@link KeyPolicyDef}</li>
  * </ul>
- * 
+ *
  * @author Robert von Burg <eitch@eitchnet.ch>
  */
 public class DefaultPolicyHandler extends StrolchComponent implements PolicyHandler, PolicyDefVisitor {
@@ -84,10 +84,12 @@ public class DefaultPolicyHandler extends StrolchComponent implements PolicyHand
 
 			Class<T> clazz = policyDef.accept(this);
 			Constructor<T> constructor = clazz.getConstructor(ComponentContainer.class, StrolchTransaction.class);
+			if (constructor == null)
+				throw new IllegalStateException(
+						"Class" + clazz.getName() + " is missing constructor (ComponentContainer, StrolchTransaction)");
 			return constructor.newInstance(getContainer(), tx);
 
-		} catch (NoSuchMethodException | SecurityException | InstantiationException | IllegalAccessException
-				| IllegalArgumentException | InvocationTargetException | ClassNotFoundException e) {
+		} catch (NoSuchMethodException | SecurityException | InstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException | ClassNotFoundException e) {
 			throw new StrolchPolicyException(
 					MessageFormat.format("Failed to instantiate policy {0} due to {1}", policyDef, e.getMessage()), e);
 		}
@@ -146,9 +148,10 @@ public class DefaultPolicyHandler extends StrolchComponent implements PolicyHand
 
 						// assert API is a Policy
 						if (!StrolchPolicy.class.isAssignableFrom(implClass)) {
-							throw new StrolchPolicyException("Invalid " + StrolchPolicyFileParser.POLICY
-									+ " configuration for Type=" + type + " Key=" + key + " as " + className
-									+ " is not a " + StrolchPolicy.class.getName());
+							throw new StrolchPolicyException(
+									"Invalid " + StrolchPolicyFileParser.POLICY + " configuration for Type=" + type
+											+ " Key=" + key + " as " + className + " is not a " + StrolchPolicy.class
+											.getName());
 						}
 
 						if (!apiClass.isAssignableFrom(implClass)) {
@@ -162,13 +165,15 @@ public class DefaultPolicyHandler extends StrolchComponent implements PolicyHand
 						this.classByTypeMap.addElement(type, key, (Class<? extends StrolchPolicy>) implClass);
 
 					} catch (ClassNotFoundException e) {
-						throw new StrolchPolicyException("Invalid " + StrolchPolicyFileParser.POLICY
-								+ " configuration for Type=" + type + " Key=" + key + " due to " + e.getMessage(), e);
+						throw new StrolchPolicyException(
+								"Invalid " + StrolchPolicyFileParser.POLICY + " configuration for Type=" + type
+										+ " Key=" + key + " due to " + e.getMessage(), e);
 					}
 				}
 			} catch (ClassNotFoundException e) {
-				throw new StrolchPolicyException("Invalid " + StrolchPolicyFileParser.POLICY_TYPE
-						+ " configuration for Type=" + type + " due to " + e.getMessage(), e);
+				throw new StrolchPolicyException(
+						"Invalid " + StrolchPolicyFileParser.POLICY_TYPE + " configuration for Type=" + type
+								+ " due to " + e.getMessage(), e);
 			}
 		}
 	}