/*

  * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * 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

  * version 2 for more details (a copy is included in the LICENSE file that

  * 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,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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  */

 package java.lang.invoke;

 import java.io.Serializable;

 import java.lang.reflect.Method;

 import java.security.AccessController;

 import java.security.PrivilegedActionException;

 import java.security.PrivilegedExceptionAction;

 import java.util.Objects;

 /**

  * Serialized form of a lambda expression.  The properties of this class

  * represent the information that is present at the lambda factory site, including

  * static metafactory arguments such as the identity of the primary functional

  * interface method and the identity of the implementation method, as well as

  * dynamic metafactory arguments such as values captured from the lexical scope

  * at the time of lambda capture.

  *

  * <p>Implementors of serializable lambdas, such as compilers or language

  * runtime libraries, are expected to ensure that instances deserialize properly.

  * One means to do so is to ensure that the {@code writeReplace} method returns

  * an instance of {@code SerializedLambda}, rather than allowing default

  * serialization to proceed.

  *

  * <p>{@code SerializedLambda} has a {@code readResolve} method that looks for

  * a (possibly private) static method called

  * {@code $deserializeLambda$(SerializedLambda)} in the capturing class, invokes

  * that with itself as the first argument, and returns the result.  Lambda classes

  * implementing {@code $deserializeLambda$} are responsible for validating

  * that the properties of the {@code SerializedLambda} are consistent with a

  * lambda actually captured by that class.

  *

  * @see LambdaMetafactory

  */

 public final class SerializedLambda implements Serializable {

     private static final long serialVersionUID = 8025925345765570181L;

     private final Class<?> capturingClass;

     private final String functionalInterfaceClass;

     private final String functionalInterfaceMethodName;

     private final String functionalInterfaceMethodSignature;

     private final String implClass;

     private final String implMethodName;

     private final String implMethodSignature;

     private final int implMethodKind;

     private final String instantiatedMethodType;

     private final Object[] capturedArgs;

     /**

      * Create a {@code SerializedLambda} from the low-level information present

      * at the lambda factory site.

      *

      * @param capturingClass The class in which the lambda expression appears

      * @param functionalInterfaceClass Name, in slash-delimited form, of static

      *                                 type of the returned lambda object

      * @param functionalInterfaceMethodName Name of the functional interface

      *                                      method for the present at the

      *                                      lambda factory site

      * @param functionalInterfaceMethodSignature Signature of the functional

      *                                           interface method present at

      *                                           the lambda factory site

      * @param implMethodKind Method handle kind for the implementation method

      * @param implClass Name, in slash-delimited form, for the class holding

      *                  the implementation method

      * @param implMethodName Name of the implementation method

      * @param implMethodSignature Signature of the implementation method

      * @param instantiatedMethodType The signature of the primary functional

      *                               interface method after type variables

      *                               are substituted with their instantiation

      *                               from the capture site

      * @param capturedArgs The dynamic arguments to the lambda factory site,

      *                     which represent variables captured by

      *                     the lambda

      */

     public SerializedLambda(Class<?> capturingClass,

                             String functionalInterfaceClass,

                             String functionalInterfaceMethodName,

                             String functionalInterfaceMethodSignature,

                             int implMethodKind,

                             String implClass,

                             String implMethodName,

                             String implMethodSignature,

                             String instantiatedMethodType,

                             Object[] capturedArgs) {

         this.capturingClass = capturingClass;

         this.functionalInterfaceClass = functionalInterfaceClass;

         this.functionalInterfaceMethodName = functionalInterfaceMethodName;

         this.functionalInterfaceMethodSignature = functionalInterfaceMethodSignature;

         this.implMethodKind = implMethodKind;

         this.implClass = implClass;

         this.implMethodName = implMethodName;

         this.implMethodSignature = implMethodSignature;

         this.instantiatedMethodType = instantiatedMethodType;

         this.capturedArgs = Objects.requireNonNull(capturedArgs).clone();

     }

     /**

      * Get the name of the class that captured this lambda.

      * @return the name of the class that captured this lambda

      */

     public String getCapturingClass() {

         return capturingClass.getName().replace('.', '/');

     }

     /**

      * Get the name of the invoked type to which this

      * lambda has been converted

      * @return the name of the functional interface class to which

      * this lambda has been converted

      */

     public String getFunctionalInterfaceClass() {

         return functionalInterfaceClass;

     }

     /**

      * Get the name of the primary method for the functional interface

      * to which this lambda has been converted.

      * @return the name of the primary methods of the functional interface

      */

     public String getFunctionalInterfaceMethodName() {

         return functionalInterfaceMethodName;

     }

     /**

      * Get the signature of the primary method for the functional

      * interface to which this lambda has been converted.

      * @return the signature of the primary method of the functional

      * interface

      */

     public String getFunctionalInterfaceMethodSignature() {

         return functionalInterfaceMethodSignature;

     }

     /**

      * Get the name of the class containing the implementation

      * method.

      * @return the name of the class containing the implementation

      * method

      */

     public String getImplClass() {

         return implClass;

     }

     /**

      * Get the name of the implementation method.

      * @return the name of the implementation method

      */

     public String getImplMethodName() {

         return implMethodName;

     }

     /**

      * Get the signature of the implementation method.

      * @return the signature of the implementation method

      */

     public String getImplMethodSignature() {

         return implMethodSignature;

     }

     /**

      * Get the method handle kind (see {@link MethodHandleInfo}) of

      * the implementation method.

      * @return the method handle kind of the implementation method

      */

     public int getImplMethodKind() {

         return implMethodKind;

     }

     /**

      * Get the signature of the primary functional interface method

      * after type variables are substituted with their instantiation

      * from the capture site.

      * @return the signature of the primary functional interface method

      * after type variable processing

      */

     public final String getInstantiatedMethodType() {

         return instantiatedMethodType;

     }

     /**

      * Get the count of dynamic arguments to the lambda capture site.

      * @return the count of dynamic arguments to the lambda capture site

      */

     public int getCapturedArgCount() {

         return capturedArgs.length;

     }

     /**

      * Get a dynamic argument to the lambda capture site.

      * @param i the argument to capture

      * @return a dynamic argument to the lambda capture site

      */

     public Object getCapturedArg(int i) {

         return capturedArgs[i];

     }

     private Object readResolve() throws ReflectiveOperationException {

         try {

             Method deserialize = AccessController.doPrivileged(new PrivilegedExceptionAction<Method>() {

                 @Override

                 public Method run() throws Exception {

                     Method m = capturingClass.getDeclaredMethod("$deserializeLambda$", SerializedLambda.class);

                     m.setAccessible(true);

                     return m;

                 }

             });

             return deserialize.invoke(null, this);

         }

         catch (PrivilegedActionException e) {

             Exception cause = e.getException();

             if (cause instanceof ReflectiveOperationException)

                 throw (ReflectiveOperationException) cause;

             else if (cause instanceof RuntimeException)

                 throw (RuntimeException) cause;

             else

                 throw new RuntimeException("Exception in SerializedLambda.readResolve", e);

         }

     }

     @Override

     public String toString() {

         return String.format("SerializedLambda[%s=%s, %s=%s.%s:%s, " +

                              "%s=%s %s.%s:%s, %s=%s, %s=%d]",

                              "capturingClass", capturingClass,

                              "functionalInterfaceMethod", functionalInterfaceClass,

                                functionalInterfaceMethodName,

                                functionalInterfaceMethodSignature,

                              "implementation",

                                null,

                                implClass, implMethodName, implMethodSignature,

                              "instantiatedMethodType", instantiatedMethodType,

                              "numCaptured", capturedArgs.length);

     }

 }