org.wildfly.security.util.StringMapping Maven / Gradle / Ivy
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* Copyright 2016 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed 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.wildfly.security.util;
import java.util.function.Function;
import org.wildfly.common.Assert;
/**
* An efficient mapping of enumerated strings to some other object.
*
* @author David M. Lloyd
*/
public final class StringMapping {
private final StringEnumeration stringEnumeration;
private final T[] items;
/**
* Construct a new instance.
*
* @param stringEnumeration the string enumeration (must not be {@code null})
* @param mapping the mapping function (must not be {@code null})
*/
public StringMapping(final StringEnumeration stringEnumeration, final Function mapping) {
Assert.checkNotNullParam("stringEnumeration", stringEnumeration);
Assert.checkNotNullParam("mapping", mapping);
this.stringEnumeration = stringEnumeration;
@SuppressWarnings("unchecked")
final T[] items = (T[]) new Object[stringEnumeration.size()];
for (int i = 0; i < stringEnumeration.size(); i ++) {
items[i] = mapping.apply(stringEnumeration.nameOf(i));
}
this.items = items;
}
/**
* Get an item from this mapping by ID.
*
* @param index the index to look up
* @return the mapped item for the given ID
* @throws IllegalArgumentException if the given index is out of range
*/
public T getItemById(int index) throws IllegalArgumentException {
Assert.checkMinimumParameter("index", 0, index);
Assert.checkMaximumParameter("index", stringEnumeration.size() - 1, index);
return items[index];
}
/**
* Get an item from this mapping by the corresponding string name.
*
* @param str the string name
* @return the item
* @throws IllegalArgumentException if the string name is unknown
*/
public T getItemByString(String str) throws IllegalArgumentException {
Assert.checkNotNullParam("str", str);
return items[stringEnumeration.indexOf(str)];
}
/**
* Get the string enumeration for this mapping.
*
* @return the string enumeration for this mapping (not {@code null})
*/
public StringEnumeration getStringEnumeration() {
return stringEnumeration;
}
}