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    1   /*
    2    * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved.
    3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
    4    *
    5    * This code is free software; you can redistribute it and/or modify it
    6    * under the terms of the GNU General Public License version 2 only, as
    7    * published by the Free Software Foundation.  Oracle designates this
    8    * particular file as subject to the "Classpath" exception as provided
    9    * by Oracle in the LICENSE file that accompanied this code.
   10    *
   11    * This code is distributed in the hope that it will be useful, but WITHOUT
   12    * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   13    * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   14    * version 2 for more details (a copy is included in the LICENSE file that
   15    * accompanied this code).
   16    *
   17    * You should have received a copy of the GNU General Public License version
   18    * 2 along with this work; if not, write to the Free Software Foundation,
   19    * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   20    *
   21    * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   22    * or visit www.oracle.com if you need additional information or have any
   23    * questions.
   24    */
   25   
   26   package sun.reflect.generics.reflectiveObjects;
   27   
   28   import sun.reflect.generics.tree.FieldTypeSignature;
   29   
   30   import java.lang.reflect.MalformedParameterizedTypeException;
   31   import java.lang.reflect.Method;
   32   import java.lang.reflect.ParameterizedType;
   33   import java.lang.reflect.Type;
   34   import java.lang.reflect.TypeVariable;
   35   import java.util.Arrays;
   36   
   37   
   38   /** Implementing class for ParameterizedType interface. */
   39   
   40   public class ParameterizedTypeImpl implements ParameterizedType {
   41       private Type[] actualTypeArguments;
   42       private Class<?>  rawType;
   43       private Type   ownerType;
   44   
   45       private ParameterizedTypeImpl(Class<?> rawType,
   46                                     Type[] actualTypeArguments,
   47                                     Type ownerType) {
   48           this.actualTypeArguments = actualTypeArguments;
   49           this.rawType             = rawType;
   50           if (ownerType != null) {
   51               this.ownerType = ownerType;
   52           } else { this.ownerType = rawType.getDeclaringClass();}
   53           validateConstructorArguments();
   54       }
   55   
   56       private void validateConstructorArguments() {
   57           TypeVariable/*<?>*/[] formals = rawType.getTypeParameters();
   58           // check correct arity of actual type args
   59           if (formals.length != actualTypeArguments.length){
   60               throw new MalformedParameterizedTypeException();
   61           }
   62           for (int i = 0; i < actualTypeArguments.length; i++) {
   63               // check actuals against formals' bounds
   64           }
   65   
   66       }
   67   
   68       /**
   69        * Static factory. Given a (generic) class, actual type arguments
   70        * and an owner type, creates a parameterized type.
   71        * This class can be instantiated with a a raw type that does not
   72        * represent a generic type, provided the list of actual type
   73        * arguments is empty.
   74        * If the ownerType argument is null, the declaring class of the
   75        * raw type is used as the owner type.
   76        * <p> This method throws a MalformedParameterizedTypeException
   77        * under the following circumstances:
   78        * If the number of actual type arguments (i.e., the size of the
   79        * array <tt>typeArgs</tt>) does not correspond to the number of
   80        * formal type arguments.
   81        * If any of the actual type arguments is not an instance of the
   82        * bounds on the corresponding formal.
   83        * @param rawType the Class representing the generic type declaration being
   84        * instantiated
   85        * @param actualTypeArguments - a (possibly empty) array of types
   86        * representing the actual type arguments to the parameterized type
   87        * @param ownerType - the enclosing type, if known.
   88        * @return An instance of <tt>ParameterizedType</tt>
   89        * @throws MalformedParameterizedTypeException - if the instantiation
   90        * is invalid
   91        */
   92       public static ParameterizedTypeImpl make(Class<?> rawType,
   93                                                Type[] actualTypeArguments,
   94                                                Type ownerType) {
   95           return new ParameterizedTypeImpl(rawType, actualTypeArguments,
   96                                            ownerType);
   97       }
   98   
   99   
  100       /**
  101        * Returns an array of <tt>Type</tt> objects representing the actual type
  102        * arguments to this type.
  103        *
  104        * <p>Note that in some cases, the returned array be empty. This can occur
  105        * if this type represents a non-parameterized type nested within
  106        * a parameterized type.
  107        *
  108        * @return an array of <tt>Type</tt> objects representing the actual type
  109        *     arguments to this type
  110        * @throws <tt>TypeNotPresentException</tt> if any of the
  111        *     actual type arguments refers to a non-existent type declaration
  112        * @throws <tt>MalformedParameterizedTypeException</tt> if any of the
  113        *     actual type parameters refer to a parameterized type that cannot
  114        *     be instantiated for any reason
  115        * @since 1.5
  116        */
  117       public Type[] getActualTypeArguments() {
  118           return actualTypeArguments.clone();
  119       }
  120   
  121       /**
  122        * Returns the <tt>Type</tt> object representing the class or interface
  123        * that declared this type.
  124        *
  125        * @return the <tt>Type</tt> object representing the class or interface
  126        *     that declared this type
  127        */
  128       public Class<?> getRawType() {
  129           return rawType;
  130       }
  131   
  132   
  133       /**
  134        * Returns a <tt>Type</tt> object representing the type that this type
  135        * is a member of.  For example, if this type is <tt>O<T>.I<S></tt>,
  136        * return a representation of <tt>O<T></tt>.
  137        *
  138        * <p>If this type is a top-level type, <tt>null</tt> is returned.
  139        *
  140        * @return a <tt>Type</tt> object representing the type that
  141        *     this type is a member of. If this type is a top-level type,
  142        *     <tt>null</tt> is returned
  143        * @throws <tt>TypeNotPresentException</tt> if the owner type
  144        *     refers to a non-existent type declaration
  145        * @throws <tt>MalformedParameterizedTypeException</tt> if the owner type
  146        *     refers to a parameterized type that cannot be instantiated
  147        *     for any reason
  148        *
  149        */
  150       public Type getOwnerType() {
  151           return ownerType;
  152       }
  153   
  154       /*
  155        * From the JavaDoc for java.lang.reflect.ParameterizedType
  156        * "Instances of classes that implement this interface must
  157        * implement an equals() method that equates any two instances
  158        * that share the same generic type declaration and have equal
  159        * type parameters."
  160        */
  161       @Override
  162       public boolean equals(Object o) {
  163           if (o instanceof ParameterizedType) {
  164               // Check that information is equivalent
  165               ParameterizedType that = (ParameterizedType) o;
  166   
  167               if (this == that)
  168                   return true;
  169   
  170               Type thatOwner   = that.getOwnerType();
  171               Type thatRawType = that.getRawType();
  172   
  173               if (false) { // Debugging
  174                   boolean ownerEquality = (ownerType == null ?
  175                                            thatOwner == null :
  176                                            ownerType.equals(thatOwner));
  177                   boolean rawEquality = (rawType == null ?
  178                                          thatRawType == null :
  179                                          rawType.equals(thatRawType));
  180   
  181                   boolean typeArgEquality = Arrays.equals(actualTypeArguments, // avoid clone
  182                                                           that.getActualTypeArguments());
  183                   for (Type t : actualTypeArguments) {
  184                       System.out.printf("\t\t%s%s%n", t, t.getClass());
  185                   }
  186   
  187                   System.out.printf("\towner %s\traw %s\ttypeArg %s%n",
  188                                     ownerEquality, rawEquality, typeArgEquality);
  189                   return ownerEquality && rawEquality && typeArgEquality;
  190               }
  191   
  192   
  193               return
  194                   (ownerType == null ?
  195                    thatOwner == null :
  196                    ownerType.equals(thatOwner)) &&
  197                   (rawType == null ?
  198                    thatRawType == null :
  199                    rawType.equals(thatRawType)) &&
  200                   Arrays.equals(actualTypeArguments, // avoid clone
  201                                 that.getActualTypeArguments());
  202           } else
  203               return false;
  204       }
  205   
  206       @Override
  207       public int hashCode() {
  208           return
  209               Arrays.hashCode(actualTypeArguments) ^
  210               (ownerType == null ? 0 : ownerType.hashCode() ) ^
  211               (rawType == null   ? 0 : rawType.hashCode() );
  212       }
  213   
  214       public String toString() {
  215           StringBuilder sb = new StringBuilder();
  216   
  217           if (ownerType != null) {
  218               if (ownerType instanceof Class)
  219                   sb.append(((Class)ownerType).getName());
  220               else
  221                   sb.append(ownerType.toString());
  222   
  223               sb.append(".");
  224   
  225               if (ownerType instanceof ParameterizedTypeImpl) {
  226                   // Find simple name of nested type by removing the
  227                   // shared prefix with owner.
  228                   sb.append(rawType.getName().replace( ((ParameterizedTypeImpl)ownerType).rawType.getName() + "$",
  229                                            ""));
  230               } else
  231                   sb.append(rawType.getName());
  232           } else
  233               sb.append(rawType.getName());
  234   
  235           if (actualTypeArguments != null &&
  236               actualTypeArguments.length > 0) {
  237               sb.append("<");
  238               boolean first = true;
  239               for(Type t: actualTypeArguments) {
  240                   if (!first)
  241                       sb.append(", ");
  242                   if (t instanceof Class)
  243                       sb.append(((Class)t).getName());
  244                   else
  245                       sb.append(t.toString());
  246                   first = false;
  247               }
  248               sb.append(">");
  249           }
  250   
  251           return sb.toString();
  252       }
  253   }

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