// Copyright (c) 2003-2012, Jodd Team (jodd.org). All Rights Reserved.
package jodd.util.collection;
import java.util.AbstractMap;
import java.util.Set;
import java.util.Iterator;
import java.util.HashSet;
/**
* Adapter for map whose keys are <code>String</code> values.
*/
public abstract class StringKeyedMapAdapter extends AbstractMap<String, Object> {
// ---------------------------------------------------------------- hooks
/**
* Hooks method that needs to be implemented by concrete subclasses.
* Gets a value associated with a key.
*/
protected abstract Object getAttribute(String key);
/**
* Hooks method that needs to be implemented by concrete subclasses.
* Puts a key-value pair in the map, overwriting
* any possible earlier value associated with the same key.
*/
protected abstract void setAttribute(String key, Object value);
/**
* Hooks method that needs to be implemented by concrete subclasses.
* Removes a key and its associated value from the
* map.
*/
protected abstract void removeAttribute(String key);
/**
* Hook method that needs to be implemented by concrete subclasses.
* Returns an enumeration listing all keys known to the map.
*/
protected abstract Iterator<String> getAttributeNames();
// ---------------------------------------------------------------- implementation
private Set<Entry<String, Object>> entries; // cached entries
/**
* Removes all attributes from the request as well as clears entries in this map.
*/
@Override
public void clear() {
entries = null;
Iterator<String> keys = getAttributeNames();
while (keys.hasNext()) {
removeAttribute(keys.next());
}
}
/**
* Returns a Set of attributes from the http request.
*/
@Override
public Set<Entry<String, Object>> entrySet() {
if (entries == null) {
entries = new HashSet<Entry<String, Object>>();
Iterator<String> iterator = getAttributeNames();
while (iterator.hasNext()) {
final String key = iterator.next();
final Object value = getAttribute(key);
entries.add(new Entry<String, Object>() {
@Override
public boolean equals(Object obj) {
Entry entry = (Entry) obj;
return ((key == null) ? (entry.getKey() == null) : key.equals(entry.getKey())) && ((value == null) ? (entry.getValue() == null) : value.equals(entry.getValue()));
}
@Override
public int hashCode() {
return ((key == null) ? 0 : key.hashCode()) ^ ((value == null) ? 0 : value.hashCode());
}
public String getKey() {
return key;
}
public Object getValue() {
return value;
}
public Object setValue(Object obj) {
setAttribute(key, obj);
return value;
}
});
}
}
return entries;
}
/**
* Returns the request attribute associated with the given key or <code>null</code> if it doesn't exist.
*/
@Override
public Object get(Object key) {
return getAttribute(key.toString());
}
/**
* Saves an attribute in the request.
*/
@Override
public Object put(String key, Object value) {
entries = null;
Object previous = get(key);
setAttribute(key, value);
return previous;
}
/**
* Removes the specified request attribute.
*/
@Override
public Object remove(Object key) {
entries = null;
Object value = get(key);
removeAttribute(key.toString());
return value;
}
}
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