1 files changed, 588 insertions, 0 deletions
diff --git a/sca-java-2.x/tags/2.0.1-RC1/modules/common-java/src/main/java/org/apache/tuscany/sca/common/java/reflection/JavaIntrospectionHelper.java b/sca-java-2.x/tags/2.0.1-RC1/modules/common-java/src/main/java/org/apache/tuscany/sca/common/java/reflection/JavaIntrospectionHelper.java
new file mode 100644
index 0000000000..73ff2e2fb0
--- /dev/null
+++ b/sca-java-2.x/tags/2.0.1-RC1/modules/common-java/src/main/java/org/apache/tuscany/sca/common/java/reflection/JavaIntrospectionHelper.java
@@ -0,0 +1,588 @@
+/*
+ * 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 ASF 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.tuscany.sca.common.java.reflection;
+
+import java.beans.Introspector;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.lang.reflect.GenericArrayType;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.lang.reflect.TypeVariable;
+import java.lang.reflect.WildcardType;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.logging.Logger;
+
+import org.apache.tuscany.sca.core.ExtensionPointRegistry;
+import org.apache.tuscany.sca.core.UtilityExtensionPoint;
+import org.oasisopen.sca.ServiceReference;
+
+/**
+ * Implements various reflection-related operations
+ * 
+ * @version $Rev$ $Date$
+ */
+public final class JavaIntrospectionHelper {
+    private static final Logger logger = Logger.getLogger(JavaIntrospectionHelper.class.getName());
+    private static final Class<?>[] EMPTY_CLASS_ARRY = new Class[0];
+
+    private ExtensionPointRegistry registry;
+
+    public JavaIntrospectionHelper(ExtensionPointRegistry registry) {
+        this.registry = registry;
+    }
+
+    public static JavaIntrospectionHelper getInstance(ExtensionPointRegistry registry) {
+        UtilityExtensionPoint utilities = registry.getExtensionPoint(UtilityExtensionPoint.class);
+        return utilities.getUtility(JavaIntrospectionHelper.class);
+    }
+
+    private static boolean matches(int modifiers, int include, int exclude) {
+        if (include != -1) {
+            if ((modifiers & include) == 0) {
+                return false;
+            }
+        }
+        if (exclude != -1) {
+            if ((modifiers & exclude) != 0) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * Recursively evaluates the type hierarchy to return all fields that are
+     * public or protected
+     * @param clazz The java class
+     * @param fields The set that collects all fields
+     * @param include The modifiers to be included
+     * @param exclude The modifiers to be excluded
+     * @return The set that collects all matched fields
+     */
+    private static Set<Field> getAllFields(Class<?> clazz, Set<Field> fields, int include, int exclude) {
+        if (clazz == null || clazz.isArray() || Object.class.equals(clazz)) {
+            return fields;
+        }
+        fields = getAllFields(clazz.getSuperclass(), fields, include, exclude);
+        Field[] declaredFields = clazz.getDeclaredFields();
+        for (final Field field : declaredFields) {
+            int modifiers = field.getModifiers();
+            if (matches(modifiers, include, exclude)) {
+                // Allow privileged access to set accessibility. Requires ReflectPermission
+                // in security policy.
+                AccessController.doPrivileged(new PrivilegedAction<Object>() {
+                    public Object run() {
+                        field.setAccessible(true); // ignore Java accessibility
+                        return null;
+                    }
+                });
+                fields.add(field);
+            }
+        }
+        return fields;
+    }
+
+    /**
+     * @param cls
+     * @return
+     */
+    public Set<Field> getAllNonStaticOrFinalFields(Class<?> cls) {
+        Set<Field> fields = new HashSet<Field>();
+        return getAllFields(cls, fields, -1, Modifier.STATIC | Modifier.FINAL);
+    }
+
+    /**
+     * @param cls
+     * @return
+     */
+    public Set<Method> getAllNonStaticMethods(Class<?> cls) {
+        Set<Method> methods = new HashSet<Method>();
+        return getAllUniqueMethods(cls, methods, -1, Modifier.STATIC);
+    }
+
+    /**
+     * Recursively evaluates the type hierarchy to return all unique methods
+     */
+    private static Set<Method> getAllUniqueMethods(Class<?> pClass, Set<Method> methods, int include, int exclude) {
+        if (pClass == null || pClass.isArray() || Object.class.equals(pClass)) {
+            return methods;
+        }
+        // we first evaluate methods of the subclass and then move to the parent
+        Method[] declaredMethods = pClass.getDeclaredMethods();
+        for (final Method declaredMethod : declaredMethods) {
+            int modifiers = declaredMethod.getModifiers();
+            if (!matches(modifiers, include, exclude)) {
+                continue;
+            }
+            if (methods.size() == 0) {
+                methods.add(declaredMethod);
+            } else {
+                List<Method> temp = new ArrayList<Method>();
+                boolean matched = false;
+                for (Method method : methods) {
+                    // only add if not already in the set from a superclass (i.e.
+                    // the method is not overridden)
+                    if (exactMethodMatch(declaredMethod, method)) {
+                        matched = true;
+                        break;
+                    }
+                }
+                if (!matched) {
+                    // Allow privileged access to set accessibility. Requires ReflectPermission
+                    // in security policy.
+                    AccessController.doPrivileged(new PrivilegedAction<Object>() {
+                        public Object run() {
+                            declaredMethod.setAccessible(true);
+                            return null;
+                        }
+                    });
+                    temp.add(declaredMethod);
+                }
+                methods.addAll(temp);
+                temp.clear();
+            }
+        }
+        // evaluate class hierarchy - this is done last to track inherited
+        // methods
+        methods = getAllUniqueMethods(pClass.getSuperclass(), methods, include, exclude);
+        return methods;
+    }
+
+    /**
+     * Finds the closest matching field with the given name, that is, a field of
+     * the exact specified type or, alternately, of a supertype.
+     * 
+     * @param name the name of the field
+     * @param type the field type
+     * @param fields the collection of fields to search
+     * @return the matching field or null if not found
+     */
+    public static Field findClosestMatchingField(String name, Class type, Set<Field> fields) {
+        Field candidate = null;
+        for (Field field : fields) {
+            if (field.getName().equals(name)) {
+                if (field.getType().equals(type)) {
+                    return field; // exact match
+                } else if (field.getType().isAssignableFrom(type) || (field.getType().isPrimitive() && primitiveAssignable(field
+                                                                                                                               .getType(),
+                                                                                                                           type))) {
+                    // We could have the situation where a field parameter is a
+                    // primitive and the demarshalled value is
+                    // an object counterpart (e.g. Integer and int)
+                    // @spec issue
+                    // either an interface or super class, so keep a reference
+                    // until
+                    // we know there are no closer types
+                    candidate = field;
+                }
+            }
+        }
+        if (candidate != null) {
+            return candidate;
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Finds the closest matching method with the given name, that is, a method
+     * taking the exact parameter types or, alternately, parameter supertypes.
+     * 
+     * @param name the name of the method
+     * @param types the method parameter types
+     * @param methods the collection of methods to search
+     * @return the matching method or null if not found
+     */
+    public static Method findClosestMatchingMethod(String name, Class[] types, Set<Method> methods) {
+        if (types == null) {
+            types = EMPTY_CLASS_ARRY;
+        }
+        Method candidate = null;
+        for (Method method : methods) {
+            if (method.getName().equals(name) && method.getParameterTypes().length == types.length) {
+                Class<?>[] params = method.getParameterTypes();
+                boolean disqualify = false;
+                boolean exactMatch = true;
+                for (int i = 0; i < params.length; i++) {
+                    if (!params[i].equals(types[i]) && !params[i].isAssignableFrom(types[i])) {
+                        // no match
+                        disqualify = true;
+                        exactMatch = false;
+                        break;
+                    } else if (!params[i].equals(types[i]) && params[i].isAssignableFrom(types[i])) {
+                        // not exact match
+                        exactMatch = false;
+                    }
+                }
+                if (disqualify) {
+                    continue;
+                } else if (exactMatch) {
+                    return method;
+                } else {
+                    candidate = method;
+                }
+            }
+        }
+        if (candidate != null) {
+            return candidate;
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Determines if two methods "match" - that is, they have the same method
+     * names and exact parameter types (one is not a supertype of the other)
+     */
+    public static boolean exactMethodMatch(Method method1, Method method2) {
+        if (!method1.getName().equals(method2.getName())) {
+            return false;
+        }
+        Class<?>[] types1 = method1.getParameterTypes();
+        Class<?>[] types2 = method2.getParameterTypes();
+        if (types1.length != types2.length) {
+            return false;
+        }
+        boolean matched = true;
+        for (int i = 0; i < types1.length; i++) {
+            if (types1[i] != types2[i]) {
+                matched = false;
+                break;
+            }
+        }
+        return matched;
+    }
+
+    public static <T> Constructor<T> getDefaultConstructor(Class<T> clazz) throws NoSuchMethodException {
+        return clazz.getConstructor();
+    }
+
+    /**
+     * Returns the simple name of a class - i.e. the class name devoid of its
+     * package qualifier
+     * 
+     * @param implClass the implementation class
+     */
+    public static String getBaseName(Class<?> implClass) {
+        return implClass.getSimpleName();
+    }
+
+    public static boolean isImmutable(Class<?> clazz) {
+        return String.class == clazz || clazz.isPrimitive()
+            || Number.class.isAssignableFrom(clazz)
+            || Boolean.class.isAssignableFrom(clazz)
+            || Character.class.isAssignableFrom(clazz)
+            || Byte.class.isAssignableFrom(clazz);
+    }
+
+    /**
+     * Takes a property name and converts it to a getter method name according
+     * to JavaBean conventions. For example, property
+     * <code>foo<code> is returned as <code>getFoo</code>
+     */
+    public static String toGetter(String name) {
+        return "get" + name.toUpperCase().substring(0, 1) + name.substring(1);
+    }
+
+    /**
+     * Takes a setter or getter method name and converts it to a property name
+     * according to JavaBean conventions. For example, <code>setFoo(var)</code>
+     * is returned as property <code>foo<code>
+     */
+    public static String toPropertyName(Method method) {
+        if (isGetter(method) || isSetter(method)) {
+            String name = method.getName();
+            if (name.startsWith("get") || name.startsWith("set")) {
+                return Introspector.decapitalize(name.substring(3));
+            } else {
+                // Starts with is
+                return Introspector.decapitalize(name.substring(2));
+            }
+        } else {
+            throw new IllegalArgumentException("Method is not a setter or getter: " + method);
+        }
+    }
+
+    public static Class<?> getErasure(Type type) {
+        if (type instanceof Class) {
+            return (Class<?>)type;
+        } else if (type instanceof GenericArrayType) {
+            // FIXME: How to deal with the []?
+            GenericArrayType arrayType = (GenericArrayType)type;
+            return getErasure(arrayType.getGenericComponentType());
+        } else if (type instanceof ParameterizedType) {
+            ParameterizedType pType = (ParameterizedType)type;
+            return getErasure(pType.getRawType());
+        } else if (type instanceof WildcardType) {
+            WildcardType wType = (WildcardType)type;
+            Type[] types = wType.getUpperBounds();
+            return getErasure(types[0]);
+        } else if (type instanceof TypeVariable) {
+            TypeVariable<?> var = (TypeVariable<?>)type;
+            Type[] types = var.getBounds();
+            return getErasure(types[0]);
+        }
+        return null;
+    }
+
+    public static Class<?> getBaseType(Class<?> cls, Type genericType) {
+        if (cls.isArray()) {
+            return cls.getComponentType();
+        } else if (Collection.class.isAssignableFrom(cls)) {
+            if (genericType instanceof ParameterizedType) {
+                // Collection<BaseType>
+                ParameterizedType parameterizedType = (ParameterizedType)genericType;
+                Type baseType = parameterizedType.getActualTypeArguments()[0];
+                if (baseType instanceof GenericArrayType) {
+                    // Base is array
+                    return cls;
+                } else {
+                    return getErasure(baseType);
+                }
+            } else {
+                return cls;
+            }
+        } else {
+            return cls;
+        }
+    }
+
+    public static Type getParameterType(Type type) {
+        if (type instanceof ParameterizedType) {
+            // Collection<BaseType>
+            ParameterizedType parameterizedType = (ParameterizedType)type;
+            Type baseType = parameterizedType.getActualTypeArguments()[0];
+            return baseType;
+        } else {
+            return Object.class;
+        }
+    }
+
+    public static Class<?> getBusinessInterface(Class<?> cls, Type callableReferenceType) {
+        if (ServiceReference.class.isAssignableFrom(cls) && callableReferenceType instanceof ParameterizedType) {
+            // Collection<BaseType>
+            ParameterizedType parameterizedType = (ParameterizedType)callableReferenceType;
+            Type baseType = parameterizedType.getActualTypeArguments()[0];
+            if (baseType instanceof GenericArrayType) {
+                // Base is array
+                return cls;
+            } else {
+                return getErasure(baseType);
+            }
+        }
+        return Object.class;
+    }
+
+    /**
+     * Takes a property name and converts it to a setter method name according
+     * to JavaBean conventions. For example, the property
+     * <code>foo<code> is returned as <code>setFoo(var)</code>
+     */
+    public static String toSetter(String name) {
+        return "set" + name.toUpperCase().substring(0, 1) + name.substring(1);
+    }
+
+    /**
+     * Compares a two types, assuming one is a primitive, to determine if the
+     * other is its object counterpart
+     */
+    private static boolean primitiveAssignable(Class<?> memberType, Class<?> param) {
+        if (memberType == Integer.class) {
+            return param == Integer.TYPE;
+        } else if (memberType == Double.class) {
+            return param == Double.TYPE;
+        } else if (memberType == Float.class) {
+            return param == Float.TYPE;
+        } else if (memberType == Short.class) {
+            return param == Short.TYPE;
+        } else if (memberType == Character.class) {
+            return param == Character.TYPE;
+        } else if (memberType == Boolean.class) {
+            return param == Boolean.TYPE;
+        } else if (memberType == Byte.class) {
+            return param == Byte.TYPE;
+        } else if (param == Integer.class) {
+            return memberType == Integer.TYPE;
+        } else if (param == Double.class) {
+            return memberType == Double.TYPE;
+        } else if (param == Float.class) {
+            return memberType == Float.TYPE;
+        } else if (param == Short.class) {
+            return memberType == Short.TYPE;
+        } else if (param == Character.class) {
+            return memberType == Character.TYPE;
+        } else if (param == Boolean.class) {
+            return memberType == Boolean.TYPE;
+        } else if (param == Byte.class) {
+            return memberType == Byte.TYPE;
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * Returns the generic types represented in the given type. Usage as
+     * follows: <code>
+     * JavaIntrospectionHelper.getGenerics(field.getGenericType());
+     * <p/>
+     * JavaIntrospectionHelper.getGenerics(m.getGenericParameterTypes()[0];); </code>
+     * 
+     * @return the generic types in order of declaration or an empty array if
+     *         the type is not genericized
+     */
+    public static List<? extends Type> getGenerics(Type genericType) {
+        List<Type> classes = new ArrayList<Type>();
+        if (genericType instanceof ParameterizedType) {
+            ParameterizedType ptype = (ParameterizedType)genericType;
+            // get the type arguments
+            Type[] targs = ptype.getActualTypeArguments();
+            for (Type targ : targs) {
+                classes.add(targ);
+            }
+        }
+        return classes;
+    }
+
+    /**
+     * Returns the generic type specified by the class at the given position as
+     * in: <p/> <code> public class Foo<Bar,Baz>{ //.. }
+     * <p/>
+     * JavaIntrospectionHelper.introspectGeneric(Foo.class,1); <code>
+     * <p/>
+     * will return Baz.
+     */
+    public static Class introspectGeneric(Class<?> clazz, int pos) {
+        assert clazz != null : "No class specified";
+        Type type = clazz.getGenericSuperclass();
+        if (type instanceof ParameterizedType) {
+            Type[] args = ((ParameterizedType)type).getActualTypeArguments();
+            if (args.length <= pos) {
+                throw new IllegalArgumentException("Invalid index value for generic class " + clazz.getName());
+            }
+            return (Class)((ParameterizedType)type).getActualTypeArguments()[pos];
+        } else {
+            Type[] interfaces = clazz.getGenericInterfaces();
+            for (Type itype : interfaces) {
+                if (!(itype instanceof ParameterizedType)) {
+                    continue;
+                }
+                ParameterizedType interfaceType = (ParameterizedType)itype;
+                return (Class)interfaceType.getActualTypeArguments()[0];
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Returns the set of interfaces implemented by the given class and its
+     * ancestors or a blank set if none
+     */
+    public List<Class<?>> getAllInterfaces(Class<?> clazz) {
+        List<Class<?>> implemented = new ArrayList<Class<?>>();
+        getAllInterfaces(clazz, implemented);
+        return implemented;
+    }
+
+    private static void getAllInterfaces(Class<?> clazz, List<Class<?>> implemented) {
+        Class<?>[] interfaces = clazz.getInterfaces();
+        for (Class<?> interfaze : interfaces) {
+            if (!implemented.contains(interfaze)) {
+                implemented.add(interfaze);
+            }
+        }
+        Class<?> superClass = clazz.getSuperclass();
+        // Object has no superclass so check for null
+        if (superClass != null && !superClass.equals(Object.class)) {
+            getAllInterfaces(superClass, implemented);
+        }
+    }
+
+    /**
+     * Test if a method follows the JavaBeans setter pattern
+     * @param method
+     * @return
+     */
+    public static boolean isSetter(Method method) {
+        return (void.class == method.getReturnType() && method.getParameterTypes().length == 1
+            && method.getName().startsWith("set") && method.getName().length() > 3);
+    }
+
+    /**
+     * Test if a method follows the JavaBeans getter pattern
+     * @param method
+     * @return
+     */
+    public static boolean isGetter(Method method) {
+        if (method.getParameterTypes().length == 0) {
+            return false;
+        }
+        Class<?> returnType = method.getReturnType();
+        if (returnType == void.class || returnType == Void.class) {
+            return false;
+        }
+        String name = method.getName();
+        if (returnType == boolean.class)
+            if (name.length() > 2 && name.startsWith("is")) {
+                return true;
+            }
+        return name.length() > 3 && name.startsWith("get");
+    }
+
+    private final static Map<Class<?>, String> signatures = new HashMap<Class<?>, String>();
+    static {
+        signatures.put(boolean.class, "Z");
+        signatures.put(byte.class, "B");
+        signatures.put(char.class, "C");
+        signatures.put(short.class, "S");
+        signatures.put(int.class, "I");
+        signatures.put(long.class, "J");
+        signatures.put(float.class, "F");
+        signatures.put(double.class, "D");
+    };
+
+    public static String getSignature(Class<?> cls) {
+        if (cls.isPrimitive()) {
+            return signatures.get(cls);
+        }
+        if (cls.isArray()) {
+            return "[" + getSignature(cls.getComponentType());
+        }
+        return "L" + cls.getName().replace('.', '/') + ";";
+    }
+
+    public static Class<?> getArrayType(Class<?> componentType, int dims) throws ClassNotFoundException {
+        StringBuffer buf = new StringBuffer();
+        for (int i = 0; i < dims; i++) {
+            buf.append('[');
+        }
+        buf.append(getSignature(componentType));
+        return Class.forName(buf.toString(), false, componentType.getClassLoader());
+    }
+}