/*
* Copyright 2002-2005 the original author or authors.
*
* 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 net.sf.sojo.core;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
/**
* If the converter find a repeated (known) object (by cycles in a object graph), than exchange
* this object through a unique id.
*
*
* @author Linke
*
*/
public class UniqueIdGenerator {
public static final String UNIQUE_ID_PROPERTY = "~unique-id~";
public static final int MINIMAL_UNIQUE_ID = 0;
private int currentUniqueID = 0;
private int minimalUniqueID = MINIMAL_UNIQUE_ID;
private boolean withHashCodeInUniqueId = false;
private Map uniqueIdObjectMap = null;
public UniqueIdGenerator() {
uniqueIdObjectMap = new HashMap();
}
public void setMinimalUniqueID(int pvMinimalUniqueID) { minimalUniqueID = pvMinimalUniqueID; }
public int getMinimalUniqueID() { return minimalUniqueID; }
public void setWithHashCodeInUniqueId(boolean pvWithHashCodeInUniqueId) { withHashCodeInUniqueId = pvWithHashCodeInUniqueId; }
public boolean getWithHashCodeInUniqueId() { return withHashCodeInUniqueId; }
public int getCurrentUniqueID() { return currentUniqueID; }
protected String getStringRepresentationFromId (int pvUniqueId, Object pvObject) {
String lvUniqueId = Integer.toString(pvUniqueId);
if (getWithHashCodeInUniqueId() == true) {
lvUniqueId = lvUniqueId + "-" + pvObject.hashCode();
}
return lvUniqueId;
}
public final String getUniqueId(Object pvObject) {
if (pvObject == null) {return null; }
String lvUniqueId = null;
if ( ! (pvObject instanceof Collection) && ! (pvObject instanceof Map)) {
lvUniqueId = (String) uniqueIdObjectMap.get(pvObject);
if (lvUniqueId == null){
lvUniqueId = getStringRepresentationFromId(currentUniqueID, pvObject);
currentUniqueID++;
uniqueIdObjectMap.put(pvObject, lvUniqueId);
}
}
return lvUniqueId;
}
public final static String getUniqueIdStringByNumber(String pvNumberString) {
return UniqueIdGenerator.UNIQUE_ID_PROPERTY + pvNumberString;
}
public final boolean isKnownObject(Object pvObject) {
if (pvObject instanceof Collection || pvObject instanceof Map) {
return false;
} else {
return uniqueIdObjectMap.containsKey(pvObject);
}
}
public Object getObjectByUniqueId (String pvUniqueId) {
Iterator iter = uniqueIdObjectMap.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry lvEntry = (Entry) iter.next();
if (lvEntry.getKey().equals(pvUniqueId)) {
return lvEntry.getValue();
}
}
return null;
}
public final Object addObject(String pvUniqueId, Object pvObject) {
return uniqueIdObjectMap.put(pvUniqueId, pvObject);
}
public void clear() {
uniqueIdObjectMap.clear();
}
}
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