diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/java.base/share/classes/java/io/ObjectStreamField.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/io/ObjectStreamField.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,354 @@
+/*
+ * Copyright (c) 1996, 2015, 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.io;
+
+import java.lang.reflect.Field;
+import jdk.internal.reflect.CallerSensitive;
+import jdk.internal.reflect.Reflection;
+import sun.reflect.misc.ReflectUtil;
+
+/**
+ * A description of a Serializable field from a Serializable class.  An array
+ * of ObjectStreamFields is used to declare the Serializable fields of a class.
+ *
+ * @author      Mike Warres
+ * @author      Roger Riggs
+ * @see ObjectStreamClass
+ * @since 1.2
+ */
+public class ObjectStreamField
+    implements Comparable<Object>
+{
+
+    /** field name */
+    private final String name;
+    /** canonical JVM signature of field type, if given */
+    private final String signature;
+    /** field type (Object.class if unknown non-primitive type) */
+    private final Class<?> type;
+    /** lazily constructed signature for the type, if no explicit signature */
+    private String typeSignature;
+    /** whether or not to (de)serialize field values as unshared */
+    private final boolean unshared;
+    /** corresponding reflective field object, if any */
+    private final Field field;
+    /** offset of field value in enclosing field group */
+    private int offset;
+
+    /**
+     * Create a Serializable field with the specified type.  This field should
+     * be documented with a <code>serialField</code> tag.
+     *
+     * @param   name the name of the serializable field
+     * @param   type the <code>Class</code> object of the serializable field
+     */
+    public ObjectStreamField(String name, Class<?> type) {
+        this(name, type, false);
+    }
+
+    /**
+     * Creates an ObjectStreamField representing a serializable field with the
+     * given name and type.  If unshared is false, values of the represented
+     * field are serialized and deserialized in the default manner--if the
+     * field is non-primitive, object values are serialized and deserialized as
+     * if they had been written and read by calls to writeObject and
+     * readObject.  If unshared is true, values of the represented field are
+     * serialized and deserialized as if they had been written and read by
+     * calls to writeUnshared and readUnshared.
+     *
+     * @param   name field name
+     * @param   type field type
+     * @param   unshared if false, write/read field values in the same manner
+     *          as writeObject/readObject; if true, write/read in the same
+     *          manner as writeUnshared/readUnshared
+     * @since   1.4
+     */
+    public ObjectStreamField(String name, Class<?> type, boolean unshared) {
+        if (name == null) {
+            throw new NullPointerException();
+        }
+        this.name = name;
+        this.type = type;
+        this.unshared = unshared;
+        this.field = null;
+        this.signature = null;
+    }
+
+    /**
+     * Creates an ObjectStreamField representing a field with the given name,
+     * signature and unshared setting.
+     */
+    ObjectStreamField(String name, String signature, boolean unshared) {
+        if (name == null) {
+            throw new NullPointerException();
+        }
+        this.name = name;
+        this.signature = signature.intern();
+        this.unshared = unshared;
+        this.field = null;
+
+        switch (signature.charAt(0)) {
+            case 'Z': type = Boolean.TYPE; break;
+            case 'B': type = Byte.TYPE; break;
+            case 'C': type = Character.TYPE; break;
+            case 'S': type = Short.TYPE; break;
+            case 'I': type = Integer.TYPE; break;
+            case 'J': type = Long.TYPE; break;
+            case 'F': type = Float.TYPE; break;
+            case 'D': type = Double.TYPE; break;
+            case 'L':
+            case '[': type = Object.class; break;
+            default: throw new IllegalArgumentException("illegal signature");
+        }
+    }
+
+    /**
+     * Returns JVM type signature for given primitive.
+     */
+    private static String getPrimitiveSignature(Class<?> cl) {
+        if (cl == Integer.TYPE)
+            return "I";
+        else if (cl == Byte.TYPE)
+            return "B";
+        else if (cl == Long.TYPE)
+            return "J";
+        else if (cl == Float.TYPE)
+            return "F";
+        else if (cl == Double.TYPE)
+            return "D";
+        else if (cl == Short.TYPE)
+            return "S";
+        else if (cl == Character.TYPE)
+            return "C";
+        else if (cl == Boolean.TYPE)
+            return "Z";
+        else if (cl == Void.TYPE)
+            return "V";
+        else
+            throw new InternalError();
+    }
+
+    /**
+     * Returns JVM type signature for given class.
+     */
+    static String getClassSignature(Class<?> cl) {
+        if (cl.isPrimitive()) {
+            return getPrimitiveSignature(cl);
+        } else {
+            return appendClassSignature(new StringBuilder(), cl).toString();
+        }
+    }
+
+    static StringBuilder appendClassSignature(StringBuilder sbuf, Class<?> cl) {
+        while (cl.isArray()) {
+            sbuf.append('[');
+            cl = cl.getComponentType();
+        }
+
+        if (cl.isPrimitive()) {
+            sbuf.append(getPrimitiveSignature(cl));
+        } else {
+            sbuf.append('L').append(cl.getName().replace('.', '/')).append(';');
+        }
+
+        return sbuf;
+    }
+
+    /**
+     * Creates an ObjectStreamField representing the given field with the
+     * specified unshared setting.  For compatibility with the behavior of
+     * earlier serialization implementations, a "showType" parameter is
+     * necessary to govern whether or not a getType() call on this
+     * ObjectStreamField (if non-primitive) will return Object.class (as
+     * opposed to a more specific reference type).
+     */
+    ObjectStreamField(Field field, boolean unshared, boolean showType) {
+        this.field = field;
+        this.unshared = unshared;
+        name = field.getName();
+        Class<?> ftype = field.getType();
+        type = (showType || ftype.isPrimitive()) ? ftype : Object.class;
+        signature = getClassSignature(ftype).intern();
+    }
+
+    /**
+     * Get the name of this field.
+     *
+     * @return  a <code>String</code> representing the name of the serializable
+     *          field
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * Get the type of the field.  If the type is non-primitive and this
+     * <code>ObjectStreamField</code> was obtained from a deserialized {@link
+     * ObjectStreamClass} instance, then <code>Object.class</code> is returned.
+     * Otherwise, the <code>Class</code> object for the type of the field is
+     * returned.
+     *
+     * @return  a <code>Class</code> object representing the type of the
+     *          serializable field
+     */
+    @CallerSensitive
+    public Class<?> getType() {
+        if (System.getSecurityManager() != null) {
+            Class<?> caller = Reflection.getCallerClass();
+            if (ReflectUtil.needsPackageAccessCheck(caller.getClassLoader(), type.getClassLoader())) {
+                ReflectUtil.checkPackageAccess(type);
+            }
+        }
+        return type;
+    }
+
+    /**
+     * Returns character encoding of field type.  The encoding is as follows:
+     * <blockquote><pre>
+     * B            byte
+     * C            char
+     * D            double
+     * F            float
+     * I            int
+     * J            long
+     * L            class or interface
+     * S            short
+     * Z            boolean
+     * [            array
+     * </pre></blockquote>
+     *
+     * @return  the typecode of the serializable field
+     */
+    // REMIND: deprecate?
+    public char getTypeCode() {
+        return getSignature().charAt(0);
+    }
+
+    /**
+     * Return the JVM type signature.
+     *
+     * @return  null if this field has a primitive type.
+     */
+    // REMIND: deprecate?
+    public String getTypeString() {
+        return isPrimitive() ? null : getSignature();
+    }
+
+    /**
+     * Offset of field within instance data.
+     *
+     * @return  the offset of this field
+     * @see #setOffset
+     */
+    // REMIND: deprecate?
+    public int getOffset() {
+        return offset;
+    }
+
+    /**
+     * Offset within instance data.
+     *
+     * @param   offset the offset of the field
+     * @see #getOffset
+     */
+    // REMIND: deprecate?
+    protected void setOffset(int offset) {
+        this.offset = offset;
+    }
+
+    /**
+     * Return true if this field has a primitive type.
+     *
+     * @return  true if and only if this field corresponds to a primitive type
+     */
+    // REMIND: deprecate?
+    public boolean isPrimitive() {
+        char tcode = getTypeCode();
+        return ((tcode != 'L') && (tcode != '['));
+    }
+
+    /**
+     * Returns boolean value indicating whether or not the serializable field
+     * represented by this ObjectStreamField instance is unshared.
+     *
+     * @return {@code true} if this field is unshared
+     *
+     * @since 1.4
+     */
+    public boolean isUnshared() {
+        return unshared;
+    }
+
+    /**
+     * Compare this field with another <code>ObjectStreamField</code>.  Return
+     * -1 if this is smaller, 0 if equal, 1 if greater.  Types that are
+     * primitives are "smaller" than object types.  If equal, the field names
+     * are compared.
+     */
+    // REMIND: deprecate?
+    public int compareTo(Object obj) {
+        ObjectStreamField other = (ObjectStreamField) obj;
+        boolean isPrim = isPrimitive();
+        if (isPrim != other.isPrimitive()) {
+            return isPrim ? -1 : 1;
+        }
+        return name.compareTo(other.name);
+    }
+
+    /**
+     * Return a string that describes this field.
+     */
+    public String toString() {
+        return getSignature() + ' ' + name;
+    }
+
+    /**
+     * Returns field represented by this ObjectStreamField, or null if
+     * ObjectStreamField is not associated with an actual field.
+     */
+    Field getField() {
+        return field;
+    }
+
+    /**
+     * Returns JVM type signature of field (similar to getTypeString, except
+     * that signature strings are returned for primitive fields as well).
+     */
+    String getSignature() {
+        if (signature != null) {
+            return signature;
+        }
+
+        String sig = typeSignature;
+        // This lazy calculation is safe since signature can be null iff one
+        // of the public constructors are used, in which case type is always
+        // initialized to the exact type we want the signature to represent.
+        if (sig == null) {
+            typeSignature = sig = getClassSignature(type).intern();
+        }
+        return sig;
+    }
+}