--- /dev/null
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ * VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.utils;\r
+\r
+import java.lang.reflect.ParameterizedType;\r
+import java.lang.reflect.Type;\r
+\r
+public class ReflectionUtils {\r
+\r
+ /**\r
+ * For a class <code>C extends PC<P></code>, where <code>PC</code> is\r
+ * a class, not an interface, retrieves class <code>P</code>.\r
+ * \r
+ * @param clazz\r
+ * @return\r
+ */\r
+ public static Class<?> getSingleParameterType(Class<?> clazz) {\r
+\r
+ Type t = clazz.getGenericSuperclass();\r
+ if(t instanceof Class<?>) {\r
+ throw new UnsupportedOperationException("Missing parameter type for input class '" + clazz.getCanonicalName() + "'");\r
+ } else if (t instanceof ParameterizedType) {\r
+ ParameterizedType type = (ParameterizedType)t;\r
+ Type argType = type.getActualTypeArguments()[0];\r
+ if (argType instanceof Class<?>) {\r
+ return (Class<?>) argType;\r
+ } else if (argType instanceof ParameterizedType) {\r
+ // This happens if the input class X<T>\r
+ // parameter T is also parameterized.\r
+ ParameterizedType pargType = (ParameterizedType) argType;\r
+ return (Class<?>) pargType.getRawType();\r
+ } else {\r
+ throw new UnsupportedOperationException("Unsupported parameter type in class '" + clazz.getCanonicalName() + "': " + argType);\r
+ }\r
+ } else {\r
+ throw new UnsupportedOperationException("Unknown case in class '" + clazz.getCanonicalName() + "'");\r
+ }\r
+\r
+ }\r
+\r
+ /**\r
+ * Works like {@link #getSingleParameterType(Class)} assuming the retrieved\r
+ * parameter class extends <code>T</code>.\r
+ * \r
+ * @param clazz\r
+ * @return\r
+ */\r
+ @SuppressWarnings("unchecked")\r
+ public static <T> Class<T> getSingleParameterTypeExtending(Class<?> clazz) {\r
+\r
+ Type t = clazz.getGenericSuperclass();\r
+ if(t instanceof Class<?>) {\r
+ throw new UnsupportedOperationException("Missing parameter type for input class '" + clazz.getCanonicalName() + "'");\r
+ } else if (t instanceof ParameterizedType) {\r
+ ParameterizedType type = (ParameterizedType)t;\r
+ Type argType = type.getActualTypeArguments()[0];\r
+ if (argType instanceof Class<?>) {\r
+ return (Class<T>) argType;\r
+ } else if (argType instanceof ParameterizedType) {\r
+ // This happens if the input class X<T>\r
+ // parameter T is also parameterized.\r
+ ParameterizedType pargType = (ParameterizedType) argType;\r
+ return (Class<T>) pargType.getRawType();\r
+ } else {\r
+ throw new UnsupportedOperationException("Unsupported parameter type in class '" + clazz.getCanonicalName() + "': " + argType);\r
+ }\r
+ } else {\r
+ throw new UnsupportedOperationException("Unknown case in class '" + clazz.getCanonicalName() + "'");\r
+ }\r
+\r
+ }\r
+\r
+}\r