/*
* 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
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* 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
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