feat(jdk8): move files to new folder to avoid resources compiled.

jdkSrc/jdk8/com/sun/beans/WeakCache.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2008, 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 com.sun.beans;
+
+import java.lang.ref.Reference;
+import java.lang.ref.WeakReference;
+
+import java.util.Map;
+import java.util.WeakHashMap;
+
+/**
+ * A hashtable-based cache with weak keys and weak values.
+ * An entry in the map will be automatically removed
+ * when its key is no longer in the ordinary use.
+ * A value will be automatically removed as well
+ * when it is no longer in the ordinary use.
+ *
+ * @since 1.7
+ *
+ * @author Sergey A. Malenkov
+ */
+public final class WeakCache<K, V> {
+    private final Map<K, Reference<V>> map = new WeakHashMap<K, Reference<V>>();
+
+    /**
+     * Returns a value to which the specified {@code key} is mapped,
+     * or {@code null} if this map contains no mapping for the {@code key}.
+     *
+     * @param key  the key whose associated value is returned
+     * @return a value to which the specified {@code key} is mapped
+     */
+    public V get(K key) {
+        Reference<V> reference = this.map.get(key);
+        if (reference == null) {
+            return null;
+        }
+        V value = reference.get();
+        if (value == null) {
+            this.map.remove(key);
+        }
+        return value;
+    }
+
+    /**
+     * Associates the specified {@code value} with the specified {@code key}.
+     * Removes the mapping for the specified {@code key} from this cache
+     * if it is present and the specified {@code value} is {@code null}.
+     * If the cache previously contained a mapping for the {@code key},
+     * the old value is replaced by the specified {@code value}.
+     *
+     * @param key    the key with which the specified value is associated
+     * @param value  the value to be associated with the specified key
+     */
+    public void put(K key, V value) {
+        if (value != null) {
+            this.map.put(key, new WeakReference<V>(value));
+        }
+        else {
+            this.map.remove(key);
+        }
+    }
+
+    /**
+     * Removes all of the mappings from this cache.
+     */
+    public void clear() {
+        this.map.clear();
+    }
+}