| /* |
| // Licensed to Julian Hyde under one or more contributor license |
| // agreements. See the NOTICE file distributed with this work for |
| // additional information regarding copyright ownership. |
| // |
| // Julian Hyde 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 net.hydromatic.linq4j.expressions; |
| |
| import net.hydromatic.linq4j.Enumerator; |
| |
| import java.lang.reflect.*; |
| import java.util.*; |
| |
| /** |
| * Utilities for converting between {@link Expression}, {@link Type} and |
| * {@link Class}. |
| * |
| * @author jhyde |
| */ |
| public class Types { |
| static final Map<Class, String> PRIMITIVES = |
| new HashMap<Class, String>(); |
| |
| static { |
| PRIMITIVES.put(Boolean.TYPE, "Boolean"); |
| PRIMITIVES.put(Byte.TYPE, "Byte"); |
| PRIMITIVES.put(Character.TYPE, "Character"); |
| PRIMITIVES.put(Short.TYPE, "Short"); |
| PRIMITIVES.put(Integer.TYPE, "Integer"); |
| PRIMITIVES.put(Long.TYPE, "Long"); |
| PRIMITIVES.put(Float.TYPE, "Float"); |
| PRIMITIVES.put(Double.TYPE, "Double"); |
| PRIMITIVES.put(Void.TYPE, "Void"); |
| } |
| |
| /** Creates a type with generic parameters. */ |
| public static Type of(Type type, Type... typeArguments) { |
| if (typeArguments.length == 0) { |
| return type; |
| } |
| return new ParameterizedTypeImpl(type, toList(typeArguments), null); |
| } |
| |
| /** Returns the component type of a {@link Collection}, {@link Iterable} |
| * (including {@link net.hydromatic.linq4j.Queryable Queryable} and |
| * {@link net.hydromatic.linq4j.Enumerable Enumerable}), {@link Iterator}, |
| * {@link Enumerator}, or an array. |
| * |
| * <p>Returns null if the type is not one of these.</p> */ |
| public static Type getComponentType(Type type) { |
| Class clazz = toClass(type); |
| if (clazz.isArray()) { |
| return clazz.getComponentType(); |
| } |
| if (Collection.class.isAssignableFrom(clazz) |
| || Iterable.class.isAssignableFrom(clazz) |
| || Iterator.class.isAssignableFrom(clazz) |
| || Enumerator.class.isAssignableFrom(clazz)) |
| { |
| if (type instanceof ParameterizedType) { |
| return ((ParameterizedType) type).getActualTypeArguments()[0]; |
| } |
| return Object.class; |
| } |
| return null; |
| } |
| |
| /** Returns a list backed by a copy of an array. The contents of the list |
| * will not change even if the contents of the array are subsequently |
| * modified. */ |
| private static <T> List<T> toList(T[] ts) { |
| switch (ts.length) { |
| case 0: |
| return Collections.emptyList(); |
| case 1: |
| return Collections.singletonList(ts[0]); |
| default: |
| return Arrays.asList(ts.clone()); |
| } |
| } |
| |
| static Field getField(String fieldName, Type type) { |
| Field field; |
| try { |
| field = toClass(type).getField(fieldName); |
| } catch (NoSuchFieldException e) { |
| throw new RuntimeException( |
| "while resolving field '" + fieldName + "' in class " |
| + type, |
| e); |
| } |
| return field; |
| } |
| |
| public static Class toClass(Type type) { |
| if (type instanceof Class) { |
| return (Class) type; |
| } |
| if (type instanceof ParameterizedType) { |
| return toClass(((ParameterizedType) type).getRawType()); |
| } |
| throw new RuntimeException("unsupported type type " + type); // TODO: |
| } |
| |
| static Class[] toClassArray(Collection<Type> types) { |
| Class[] classes = new Class[types.size()]; |
| int i = 0; |
| for (Iterator<Type> iterator = types.iterator(); iterator.hasNext();) { |
| Type type = iterator.next(); |
| classes[i++] = toClass(type); |
| } |
| return classes; |
| } |
| |
| static Class[] toClassArray(Iterable<Expression> arguments) { |
| List<Class> classes = new ArrayList<Class>(); |
| for (Expression argument : arguments) { |
| classes.add(toClass(argument.getType())); |
| } |
| return classes.toArray(new Class[classes.size()]); |
| } |
| |
| static String boxClassName(Type type) { |
| if (!(type instanceof Class)) { |
| return type.toString(); |
| } |
| Class clazz = (Class) type; |
| if (clazz.isPrimitive()) { |
| return PRIMITIVES.get(clazz); |
| } else { |
| return className(clazz); |
| } |
| } |
| |
| static String className(Type type) { |
| if (!(type instanceof Class)) { |
| return type.toString(); |
| } |
| Class clazz = (Class) type; |
| if (clazz.isArray()) { |
| return className(clazz.getComponentType()) + "[]"; |
| } |
| String className = clazz.getName(); |
| if (clazz.getPackage() == Package.getPackage("java.lang") |
| && !clazz.isPrimitive()) |
| { |
| return className.substring("java.lang.".length()); |
| } |
| return className; |
| } |
| |
| public static boolean isAssignableFrom(Class clazz, Type type) { |
| return clazz.isAssignableFrom(toClass(type)); |
| } |
| |
| public static boolean isArray(Type type) { |
| return toClass(type).isArray(); |
| } |
| |
| public static Field nthField(int ordinal, Type clazz) { |
| return Types.toClass(clazz).getFields()[ordinal]; |
| } |
| |
| static boolean allAssignable( |
| boolean varArgs, Class[] parameterTypes, Class[] argumentTypes) |
| { |
| if (varArgs) { |
| if (argumentTypes.length < parameterTypes.length - 1) { |
| return false; |
| } |
| } else { |
| if (parameterTypes.length != argumentTypes.length) { |
| return false; |
| } |
| } |
| for (int i = 0; i < argumentTypes.length; i++) { |
| Class parameterType = |
| !varArgs || i < parameterTypes.length - 1 |
| ? parameterTypes[i] |
| : Object.class; |
| if (!parameterType.isAssignableFrom(argumentTypes[i])) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Finds a method of a given name that accepts a given set of arguments. |
| * Includes in its search inherited methods and methods with wider argument |
| * types. |
| * |
| * @param clazz Class against which method is invoked |
| * @param methodName Name of method |
| * @param argumentTypes Types of arguments |
| * @return A method with the given name that matches the arguments given |
| * |
| * @throws RuntimeException if method not found |
| */ |
| public static Method lookupMethod( |
| Class clazz, String methodName, Class... argumentTypes) |
| { |
| try { |
| return clazz.getMethod(methodName, argumentTypes); |
| } catch (NoSuchMethodException e) { |
| for (Method method : clazz.getMethods()) { |
| if (method.getName().equals(methodName) |
| && allAssignable( |
| method.isVarArgs(), |
| method.getParameterTypes(), |
| argumentTypes)) |
| { |
| return method; |
| } |
| } |
| throw new RuntimeException( |
| "while resolving static method '" + methodName + "' in class " |
| + clazz, |
| e); |
| } |
| } |
| |
| /** |
| * Finds a constructor of a given class that accepts a given set of |
| * arguments. Includes in its search methods with wider argument types. |
| * |
| * @param type Class against which method is invoked |
| * @param argumentTypes Types of arguments |
| * @return A method with the given name that matches the arguments given |
| * |
| * @throws RuntimeException if method not found |
| */ |
| public static Constructor lookupConstructor( |
| Type type, Class... argumentTypes) |
| { |
| final Class clazz = toClass(type); |
| for (Constructor constructor : clazz.getConstructors()) { |
| if (allAssignable( |
| constructor.isVarArgs(), |
| constructor.getParameterTypes(), |
| argumentTypes)) |
| { |
| return constructor; |
| } |
| } |
| throw new RuntimeException( |
| "while resolving constructor in class " + type + " with types " |
| + Arrays.toString(argumentTypes)); |
| } |
| |
| static class ParameterizedTypeImpl implements ParameterizedType { |
| private final Type rawType; |
| private final List<Type> typeArguments; |
| private final Type ownerType; |
| |
| ParameterizedTypeImpl( |
| Type rawType, List<Type> typeArguments, Type ownerType) |
| { |
| super(); |
| this.rawType = rawType; |
| this.typeArguments = typeArguments; |
| this.ownerType = ownerType; |
| } |
| |
| @Override |
| public String toString() { |
| final StringBuilder buf = new StringBuilder(); |
| buf.append(className(rawType)); |
| buf.append("<"); |
| int i = 0; |
| for (Type typeArgument : typeArguments) { |
| if (i++ > 0) { |
| buf.append(", "); |
| } |
| buf.append(className(typeArgument)); |
| } |
| buf.append(">"); |
| return buf.toString(); |
| } |
| |
| public Type[] getActualTypeArguments() { |
| return typeArguments.toArray(new Type[typeArguments.size()]); |
| } |
| |
| public Type getRawType() { |
| return rawType; |
| } |
| |
| public Type getOwnerType() { |
| return ownerType; |
| } |
| } |
| } |
| |
| // End Types.java |