src/java.base/share/classes/java/lang/invoke/SerializedLambda.java
changeset 47216 71c04702a3d5
parent 44255 515cf13d7791
child 50725 d5c59fab1bdb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/lang/invoke/SerializedLambda.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,259 @@
+/*
+ * 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
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+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
+ * @since 1.8
+ */
+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<>() {
+                @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() {
+        String implKind=MethodHandleInfo.referenceKindToString(implMethodKind);
+        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",
+                               implKind,
+                               implClass, implMethodName, implMethodSignature,
+                             "instantiatedMethodType", instantiatedMethodType,
+                             "numCaptured", capturedArgs.length);
+    }
+}