src/java.scripting/share/classes/javax/script/SimpleBindings.java
changeset 47216 71c04702a3d5
parent 32769 c9520bbd6754
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.scripting/share/classes/javax/script/SimpleBindings.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,224 @@
+/*
+ * Copyright (c) 2005, 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 javax.script;
+
+import java.util.Map;
+import java.util.HashMap;
+import java.util.Collection;
+import java.util.Set;
+
+/**
+ * A simple implementation of Bindings backed by
+ * a {@code HashMap} or some other specified {@code Map}.
+ *
+ * @author Mike Grogan
+ * @since 1.6
+ */
+public class SimpleBindings implements Bindings {
+
+    /**
+     * The {@code Map} field stores the attributes.
+     */
+    private Map<String,Object> map;
+
+    /**
+     * Constructor uses an existing {@code Map} to store the values.
+     * @param m The {@code Map} backing this {@code SimpleBindings}.
+     * @throws NullPointerException if m is null
+     */
+    public SimpleBindings(Map<String,Object> m) {
+        if (m == null) {
+            throw new NullPointerException();
+        }
+        this.map = m;
+    }
+
+    /**
+     * Default constructor uses a {@code HashMap}.
+     */
+    public SimpleBindings() {
+        this(new HashMap<String,Object>());
+    }
+
+    /**
+     * Sets the specified key/value in the underlying {@code map} field.
+     *
+     * @param name Name of value
+     * @param value Value to set.
+     *
+     * @return Previous value for the specified key.  Returns null if key was previously
+     * unset.
+     *
+     * @throws NullPointerException if the name is null.
+     * @throws IllegalArgumentException if the name is empty.
+     */
+    public Object put(String name, Object value) {
+        checkKey(name);
+        return map.put(name,value);
+    }
+
+    /**
+     * {@code putAll} is implemented using {@code Map.putAll}.
+     *
+     * @param toMerge The {@code Map} of values to add.
+     *
+     * @throws NullPointerException
+     *         if toMerge map is null or if some key in the map is null.
+     * @throws IllegalArgumentException
+     *         if some key in the map is an empty String.
+     */
+    public void putAll(Map<? extends String, ? extends Object> toMerge) {
+        if (toMerge == null) {
+            throw new NullPointerException("toMerge map is null");
+        }
+        for (Map.Entry<? extends String, ? extends Object> entry : toMerge.entrySet()) {
+            String key = entry.getKey();
+            checkKey(key);
+            put(key, entry.getValue());
+        }
+    }
+
+    /** {@inheritDoc} */
+    public void clear() {
+        map.clear();
+    }
+
+    /**
+     * Returns {@code true} if this map contains a mapping for the specified
+     * key.  More formally, returns {@code true} if and only if
+     * this map contains a mapping for a key {@code k} such that
+     * {@code (key==null ? k==null : key.equals(k))}.  (There can be
+     * at most one such mapping.)
+     *
+     * @param key key whose presence in this map is to be tested.
+     * @return {@code true} if this map contains a mapping for the specified
+     *         key.
+     *
+     * @throws NullPointerException if key is null
+     * @throws ClassCastException if key is not String
+     * @throws IllegalArgumentException if key is empty String
+     */
+    public boolean containsKey(Object key) {
+        checkKey(key);
+        return map.containsKey(key);
+    }
+
+    /** {@inheritDoc} */
+    public boolean containsValue(Object value) {
+        return map.containsValue(value);
+    }
+
+    /** {@inheritDoc} */
+    public Set<Map.Entry<String, Object>> entrySet() {
+        return map.entrySet();
+    }
+
+    /**
+     * Returns the value to which this map maps the specified key.  Returns
+     * {@code null} if the map contains no mapping for this key.  A return
+     * value of {@code null} does not <i>necessarily</i> indicate that the
+     * map contains no mapping for the key; it's also possible that the map
+     * explicitly maps the key to {@code null}.  The {@code containsKey}
+     * operation may be used to distinguish these two cases.
+     *
+     * <p>More formally, if this map contains a mapping from a key
+     * {@code k} to a value {@code v} such that
+     * {@code (key==null ? k==null : key.equals(k))},
+     * then this method returns {@code v}; otherwise
+     * it returns {@code null}.  (There can be at most one such mapping.)
+     *
+     * @param key key whose associated value is to be returned.
+     * @return the value to which this map maps the specified key, or
+     *         {@code null} if the map contains no mapping for this key.
+     *
+     * @throws NullPointerException if key is null
+     * @throws ClassCastException if key is not String
+     * @throws IllegalArgumentException if key is empty String
+     */
+    public Object get(Object key) {
+        checkKey(key);
+        return map.get(key);
+    }
+
+    /** {@inheritDoc} */
+    public boolean isEmpty() {
+        return map.isEmpty();
+    }
+
+    /** {@inheritDoc} */
+    public Set<String> keySet() {
+        return map.keySet();
+    }
+
+    /**
+     * Removes the mapping for this key from this map if it is present
+     * (optional operation).   More formally, if this map contains a mapping
+     * from key {@code k} to value {@code v} such that
+     * {@code (key==null ?  k==null : key.equals(k))}, that mapping
+     * is removed.  (The map can contain at most one such mapping.)
+     *
+     * <p>Returns the value to which the map previously associated the key, or
+     * {@code null} if the map contained no mapping for this key.  (A
+     * {@code null} return can also indicate that the map previously
+     * associated {@code null} with the specified key if the implementation
+     * supports {@code null} values.)  The map will not contain a mapping for
+     * the specified  key once the call returns.
+     *
+     * @param key key whose mapping is to be removed from the map.
+     * @return previous value associated with specified key, or {@code null}
+     *         if there was no mapping for key.
+     *
+     * @throws NullPointerException if key is null
+     * @throws ClassCastException if key is not String
+     * @throws IllegalArgumentException if key is empty String
+     */
+    public Object remove(Object key) {
+        checkKey(key);
+        return map.remove(key);
+    }
+
+    /** {@inheritDoc} */
+    public int size() {
+        return map.size();
+    }
+
+    /** {@inheritDoc} */
+    public Collection<Object> values() {
+        return map.values();
+    }
+
+    private void checkKey(Object key) {
+        if (key == null) {
+            throw new NullPointerException("key can not be null");
+        }
+        if (!(key instanceof String)) {
+            throw new ClassCastException("key should be a String");
+        }
+        if (key.equals("")) {
+            throw new IllegalArgumentException("key can not be empty");
+        }
+    }
+}