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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
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package sun.reflect.generics.reflectiveObjects;

import sun.reflect.generics.tree.FieldTypeSignature;

import java.lang.reflect.MalformedParameterizedTypeException;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.util.Arrays;
import java.util.StringJoiner;
import java.util.Objects;

Implementing class for ParameterizedType interface. /** Implementing class for ParameterizedType interface. */

public class ParameterizedTypeImpl implements ParameterizedType {
    private final Type[] actualTypeArguments;
    private final Class<?>  rawType;
    private final Type   ownerType;

    private ParameterizedTypeImpl(Class<?> rawType,
                                  Type[] actualTypeArguments,
                                  Type ownerType) {
        this.actualTypeArguments = actualTypeArguments;
        this.rawType             = rawType;
        this.ownerType = (ownerType != null) ? ownerType : rawType.getDeclaringClass();
        validateConstructorArguments();
    }

    private void validateConstructorArguments() {
        TypeVariable<?>[] formals = rawType.getTypeParameters();
        // check correct arity of actual type args
        if (formals.length != actualTypeArguments.length){
            throw new MalformedParameterizedTypeException();
        }
        for (int i = 0; i < actualTypeArguments.length; i++) {
            // check actuals against formals' bounds
        }
    }

    
Static factory. Given a (generic) class, actual type arguments
and an owner type, creates a parameterized type.
This class can be instantiated with a raw type that does not
represent a generic type, provided the list of actual type
arguments is empty.
If the ownerType argument is null, the declaring class of the
raw type is used as the owner type.
 This method throws a MalformedParameterizedTypeException under the following circumstances: If the number of actual type arguments (i.e., the size of the array typeArgs) does not correspond to the number of formal type arguments. If any of the actual type arguments is not an instance of the bounds on the corresponding formal. 
Params:
rawType – the Class representing the generic type declaration being
instantiated
actualTypeArguments – a (possibly empty) array of types
representing the actual type arguments to the parameterized type
ownerType – the enclosing type, if known.
Throws:
MalformedParameterizedTypeException – if the instantiation
is invalid
Returns:
An instance of ParameterizedType/**
     * Static factory. Given a (generic) class, actual type arguments
     * and an owner type, creates a parameterized type.
     * This class can be instantiated with a raw type that does not
     * represent a generic type, provided the list of actual type
     * arguments is empty.
     * If the ownerType argument is null, the declaring class of the
     * raw type is used as the owner type.
     * <p> This method throws a MalformedParameterizedTypeException
     * under the following circumstances:
     * If the number of actual type arguments (i.e., the size of the
     * array {@code typeArgs}) does not correspond to the number of
     * formal type arguments.
     * If any of the actual type arguments is not an instance of the
     * bounds on the corresponding formal.
     * @param rawType the Class representing the generic type declaration being
     * instantiated
     * @param actualTypeArguments a (possibly empty) array of types
     * representing the actual type arguments to the parameterized type
     * @param ownerType the enclosing type, if known.
     * @return An instance of {@code ParameterizedType}
     * @throws MalformedParameterizedTypeException if the instantiation
     * is invalid
     */
    public static ParameterizedTypeImpl make(Class<?> rawType,
                                             Type[] actualTypeArguments,
                                             Type ownerType) {
        return new ParameterizedTypeImpl(rawType, actualTypeArguments,
                                         ownerType);
    }


    
Returns an array of Type objects representing the actual type arguments to this type. 
Note that in some cases, the returned array be empty. This can occur
if this type represents a non-parameterized type nested within
a parameterized type.
Throws:
TypeNotPresentException – if any of the
    actual type arguments refers to a non-existent type declaration
MalformedParameterizedTypeException – if any of the
    actual type parameters refer to a parameterized type that cannot
    be instantiated for any reason
Returns:
an array of Type objects representing the actual type arguments to this type
Since:
1.5/**
     * Returns an array of {@code Type} objects representing the actual type
     * arguments to this type.
     *
     * <p>Note that in some cases, the returned array be empty. This can occur
     * if this type represents a non-parameterized type nested within
     * a parameterized type.
     *
     * @return an array of {@code Type} objects representing the actual type
     *     arguments to this type
     * @throws TypeNotPresentException if any of the
     *     actual type arguments refers to a non-existent type declaration
     * @throws MalformedParameterizedTypeException if any of the
     *     actual type parameters refer to a parameterized type that cannot
     *     be instantiated for any reason
     * @since 1.5
     */
    public Type[] getActualTypeArguments() {
        return actualTypeArguments.clone();
    }

    
Returns the Type object representing the class or interface that declared this type. 
Returns:
the Type object representing the class or interface that declared this type/**
     * Returns the {@code Type} object representing the class or interface
     * that declared this type.
     *
     * @return the {@code Type} object representing the class or interface
     *     that declared this type
     */
    public Class<?> getRawType() {
        return rawType;
    }


    
Returns a Type object representing the type that this type is a member of. For example, if this type is O<T>.I<S>, return a representation of O<T>. 
If this type is a top-level type, null is returned. 
Throws:
TypeNotPresentException – if the owner type
    refers to a non-existent type declaration
MalformedParameterizedTypeException – if the owner type
    refers to a parameterized type that cannot be instantiated
    for any reason
Returns:
a Type object representing the type that this type is a member of. If this type is a top-level type, null is returned/**
     * Returns a {@code Type} object representing the type that this type
     * is a member of.  For example, if this type is {@code O<T>.I<S>},
     * return a representation of {@code O<T>}.
     *
     * <p>If this type is a top-level type, {@code null} is returned.
     *
     * @return a {@code Type} object representing the type that
     *     this type is a member of. If this type is a top-level type,
     *     {@code null} is returned
     * @throws TypeNotPresentException if the owner type
     *     refers to a non-existent type declaration
     * @throws MalformedParameterizedTypeException if the owner type
     *     refers to a parameterized type that cannot be instantiated
     *     for any reason
     *
     */
    public Type getOwnerType() {
        return ownerType;
    }

    /*
     * From the JavaDoc for java.lang.reflect.ParameterizedType
     * "Instances of classes that implement this interface must
     * implement an equals() method that equates any two instances
     * that share the same generic type declaration and have equal
     * type parameters."
     */
    @Override
    public boolean equals(Object o) {
        if (o instanceof ParameterizedType) {
            // Check that information is equivalent
            ParameterizedType that = (ParameterizedType) o;

            if (this == that)
                return true;

            Type thatOwner   = that.getOwnerType();
            Type thatRawType = that.getRawType();

            if (false) { // Debugging
                boolean ownerEquality = (ownerType == null ?
                                         thatOwner == null :
                                         ownerType.equals(thatOwner));
                boolean rawEquality = (rawType == null ?
                                       thatRawType == null :
                                       rawType.equals(thatRawType));

                boolean typeArgEquality = Arrays.equals(actualTypeArguments, // avoid clone
                                                        that.getActualTypeArguments());
                for (Type t : actualTypeArguments) {
                    System.out.printf("\t\t%s%s%n", t, t.getClass());
                }

                System.out.printf("\towner %s\traw %s\ttypeArg %s%n",
                                  ownerEquality, rawEquality, typeArgEquality);
                return ownerEquality && rawEquality && typeArgEquality;
            }

            return
                Objects.equals(ownerType, thatOwner) &&
                Objects.equals(rawType, thatRawType) &&
                Arrays.equals(actualTypeArguments, // avoid clone
                              that.getActualTypeArguments());
        } else
            return false;
    }

    @Override
    public int hashCode() {
        return
            Arrays.hashCode(actualTypeArguments) ^
            Objects.hashCode(ownerType) ^
            Objects.hashCode(rawType);
    }

    public String toString() {
        StringBuilder sb = new StringBuilder();

        if (ownerType != null) {
            sb.append(ownerType.getTypeName());

            sb.append("$");

            if (ownerType instanceof ParameterizedTypeImpl) {
                // Find simple name of nested type by removing the
                // shared prefix with owner.
                sb.append(rawType.getName().replace( ((ParameterizedTypeImpl)ownerType).rawType.getName() + "$",
                                         ""));
            } else
               sb.append(rawType.getSimpleName());
        } else
            sb.append(rawType.getName());

        if (actualTypeArguments != null) {
            StringJoiner sj = new StringJoiner(", ", "<", ">");
            sj.setEmptyValue("");
            for(Type t: actualTypeArguments) {
                sj.add(t.getTypeName());
            }
            sb.append(sj.toString());
        }

        return sb.toString();
    }
}