com.vaadin.server.KeyMapper Maven / Gradle / Ivy
/*
* Vaadin Framework 7
*
* Copyright (C) 2000-2024 Vaadin Ltd
*
* This program is available under Vaadin Commercial License and Service Terms.
*
* See for the full
* license.
*/
package com.vaadin.server;
import java.io.Serializable;
import java.util.HashMap;
/**
* KeyMapper is the simple two-way map for generating textual keys
* for objects and retrieving the objects later with the key.
*
* @author Vaadin Ltd.
* @since 3.0
*/
public class KeyMapper implements Serializable {
private int lastKey = 0;
private final HashMap objectKeyMap = new HashMap();
private final HashMap keyObjectMap = new HashMap();
/**
* Gets key for an object.
*
* @param o
* the object.
*/
public String key(V o) {
if (o == null) {
return "null";
}
// If the object is already mapped, use existing key
String key = objectKeyMap.get(o);
if (key != null) {
return key;
}
// If the object is not yet mapped, map it
key = String.valueOf(++lastKey);
objectKeyMap.put(o, key);
keyObjectMap.put(key, o);
return key;
}
/**
* Retrieves object with the key.
*
* @param key
* the name with the desired value.
* @return the object with the key.
*/
public V get(String key) {
return keyObjectMap.get(key);
}
/**
* Removes object from the mapper.
*
* @param removeobj
* the object to be removed.
*/
public void remove(V removeobj) {
final String key = objectKeyMap.get(removeobj);
if (key != null) {
objectKeyMap.remove(removeobj);
keyObjectMap.remove(key);
}
}
/**
* Removes all objects from the mapper.
*/
public void removeAll() {
objectKeyMap.clear();
keyObjectMap.clear();
}
/**
* Checks if the given key is mapped to an object.
*
* @since 7.7
*
* @param key
* the key to check
* @return true if the key is currently mapped,
* false otherwise
*/
public boolean containsKey(String key) {
return keyObjectMap.containsKey(key);
}
}