https://tomcat.apache.org/: Tomcat Servlet Engine Core Classes and Standard implementations 
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 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.catalina.util;

import java.io.Serializable;
import java.util.Collection;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;

import org.apache.tomcat.util.res.StringManager;


Implementation of java.util.Map that includes a
locked property.  This class can be used to safely expose
Catalina internal parameter map objects to user classes without having
to clone them in order to avoid modifications.  When first created, a
ParameterMap instance is not locked.

Author:Craig R. McClanahan
Type parameters:
  • <K> – The type of Key
  • <V> – The type of Value
/**
 * Implementation of <strong>java.util.Map</strong> that includes a
 * <code>locked</code> property.  This class can be used to safely expose
 * Catalina internal parameter map objects to user classes without having
 * to clone them in order to avoid modifications.  When first created, a
 * <code>ParameterMap</code> instance is not locked.
 *
 * @param <K> The type of Key
 * @param <V> The type of Value
 *
 * @author Craig R. McClanahan
 */
public final class ParameterMap<K,V> implements Map<K,V>, Serializable {

    private static final long serialVersionUID = 2L;

    private final Map<K,V> delegatedMap;

    private final Map<K,V> unmodifiableDelegatedMap;


    
Construct a new, empty map with the default initial capacity and
load factor.

/**
     * Construct a new, empty map with the default initial capacity and
     * load factor.
     */
    public ParameterMap() {
        delegatedMap = new LinkedHashMap<>();
        unmodifiableDelegatedMap = Collections.unmodifiableMap(delegatedMap);
    }


    
Construct a new, empty map with the specified initial capacity and
default load factor.

Params:
  • initialCapacity – The initial capacity of this map
/**
     * Construct a new, empty map with the specified initial capacity and
     * default load factor.
     *
     * @param initialCapacity The initial capacity of this map
     */
    public ParameterMap(int initialCapacity) {
        delegatedMap = new LinkedHashMap<>(initialCapacity);
        unmodifiableDelegatedMap = Collections.unmodifiableMap(delegatedMap);
    }


    
Construct a new, empty map with the specified initial capacity and
load factor.

Params:
  • initialCapacity – The initial capacity of this map
  • loadFactor – The load factor of this map
/**
     * Construct a new, empty map with the specified initial capacity and
     * load factor.
     *
     * @param initialCapacity The initial capacity of this map
     * @param loadFactor The load factor of this map
     */
    public ParameterMap(int initialCapacity, float loadFactor) {
        delegatedMap = new LinkedHashMap<>(initialCapacity, loadFactor);
        unmodifiableDelegatedMap = Collections.unmodifiableMap(delegatedMap);
    }


    
Construct a new map with the same mappings as the given map.

Params:
  • map – Map whose contents are duplicated in the new map
/**
     * Construct a new map with the same mappings as the given map.
     *
     * @param map Map whose contents are duplicated in the new map
     */
    public ParameterMap(Map<K,V> map) {
        delegatedMap = new LinkedHashMap<>(map);
        unmodifiableDelegatedMap = Collections.unmodifiableMap(delegatedMap);
    }


    
The current lock state of this parameter map.

/**
     * The current lock state of this parameter map.
     */
    private boolean locked = false;


    
Returns:the locked state of this parameter map.
/**
     * @return the locked state of this parameter map.
     */
    public boolean isLocked() {
        return locked;
    }


    
Set the locked state of this parameter map.

Params:
  • locked – The new locked state
/**
     * Set the locked state of this parameter map.
     *
     * @param locked The new locked state
     */
    public void setLocked(boolean locked) {
        this.locked = locked;
    }


    
The string manager for this package.

/**
     * The string manager for this package.
     */
    private static final StringManager sm = StringManager.getManager("org.apache.catalina.util");


    
{@inheritDoc}

Throws:
/**
     * {@inheritDoc}
     *
     * @exception IllegalStateException if this map is currently locked
     */
    @Override
    public void clear() {
        checkLocked();
        delegatedMap.clear();
    }


    
{@inheritDoc}

Throws:
/**
     * {@inheritDoc}
     *
     * @exception IllegalStateException if this map is currently locked
     */
    @Override
    public V put(K key, V value) {
        checkLocked();
        return delegatedMap.put(key, value);
    }


    
{@inheritDoc}

Throws:
/**
     * {@inheritDoc}
     *
     * @exception IllegalStateException if this map is currently locked
     */
    @Override
    public void putAll(Map<? extends K,? extends V> map) {
        checkLocked();
        delegatedMap.putAll(map);
    }


    
{@inheritDoc}

Throws:
/**
     * {@inheritDoc}
     *
     * @exception IllegalStateException if this map is currently locked
     */
    @Override
    public V remove(Object key) {
        checkLocked();
        return delegatedMap.remove(key);
    }


    private void checkLocked() {
        if (locked) {
            throw new IllegalStateException(sm.getString("parameterMap.locked"));
        }
    }


    @Override
    public int size() {
        return delegatedMap.size();
    }


    @Override
    public boolean isEmpty() {
        return delegatedMap.isEmpty();
    }


    @Override
    public boolean containsKey(Object key) {
        return delegatedMap.containsKey(key);
    }


    @Override
    public boolean containsValue(Object value) {
        return delegatedMap.containsValue(value);
    }


    @Override
    public V get(Object key) {
        return delegatedMap.get(key);
    }


    
{@inheritDoc}


Returns an unmodifiable Set view of the keys contained in this map if it is locked. 
/**
     * {@inheritDoc}
     * <p>
     * Returns an <strong>unmodifiable</strong> {@link Set} view of the keys
     * contained in this map if it is locked.
     */
    @Override
    public Set<K> keySet() {
        if (locked) {
            return unmodifiableDelegatedMap.keySet();
        }

        return delegatedMap.keySet();
    }


    
{@inheritDoc}


Returns an unmodifiable Collection view of the values contained in this map if it is locked. 
/**
     * {@inheritDoc}
     * <p>
     * Returns an <strong>unmodifiable</strong> {@link Collection} view of the
     * values contained in this map if it is locked.
     */
    @Override
    public Collection<V> values() {
        if (locked) {
            return unmodifiableDelegatedMap.values();
        }

        return delegatedMap.values();
    }


    
{@inheritDoc}


Returns an unmodifiable Set view of the mappings contained in this map if it is locked. 
/**
     * {@inheritDoc}
     * <p>
     * Returns an <strong>unmodifiable</strong> {@link Set} view of the mappings
     * contained in this map if it is locked.
     */
    @Override
    public Set<java.util.Map.Entry<K, V>> entrySet() {
        if (locked) {
            return unmodifiableDelegatedMap.entrySet();
        }

        return delegatedMap.entrySet();
    }
}