com.stripe.util.CaseInsensitiveMap Maven / Gradle / Ivy
package com.stripe.util;
import java.io.Serializable;
import java.util.AbstractMap;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;
/**
* A case-insensitive {@link Map}.
*
* All keys are expected to be strings (though {@code null} is a valid key). The map remembers
* the case of the last key to be set, and {@link Map#keySet()} or {@link Map#entrySet()} will
* contain case-sensitive keys. However, querying and contains testing is case insensitive.
*/
public class CaseInsensitiveMap extends AbstractMap
implements Map, Cloneable, Serializable {
private static final long serialVersionUID = 107333939521129358L;
@SuppressWarnings("serial")
private Map> store;
/** Instantiates a new instance of the {@link CaseInsensitiveMap} class. */
public CaseInsensitiveMap() {
this.store = new HashMap>();
}
/**
* Returns an instance of {@link CaseInsensitiveMap} using the contents of another map.
*
* @param map the map to create the {@link CaseInsensitiveMap} from
* @return the {@link CaseInsensitiveMap}
*/
public static CaseInsensitiveMap of(Map map) {
if (map == null) {
return null;
}
CaseInsensitiveMap ciMap = new CaseInsensitiveMap<>();
ciMap.putAll(map);
return ciMap;
}
// Query Operations
@Override
public boolean containsKey(Object key) {
String keyLower = convertKey(key);
return this.store.containsKey(keyLower);
}
@Override
public boolean containsValue(Object value) {
return this.values().contains(value);
}
@Override
public V get(Object key) {
String keyLower = convertKey(key);
Entry entry = this.store.get(keyLower);
if (entry == null) {
return null;
}
return entry.getValue();
}
// Modification Operations
@Override
public V put(String key, V value) {
String keyLower = convertKey(key);
this.store.put(keyLower, new AbstractMap.SimpleEntry(key, value));
return value;
}
@Override
public V remove(Object key) {
String keyLower = convertKey(key);
Entry entry = this.store.remove(keyLower);
if (entry == null) {
return null;
}
return entry.getValue();
}
// Bulk Operations
@Override
public void clear() {
this.store.clear();
}
// Views
@Override
public Set keySet() {
return this.store.values().stream().map(entry -> entry.getKey()).collect(Collectors.toSet());
}
@Override
public Collection values() {
return this.store.values().stream().map(entry -> entry.getValue()).collect(Collectors.toList());
}
@Override
public Set> entrySet() {
return this.store.values().stream().collect(Collectors.toSet());
}
// Utility
private static String convertKey(Object key) {
if (key == null) {
return null;
} else if (key instanceof String) {
return ((String) key).toLowerCase();
}
throw new IllegalArgumentException("key must be a String");
}
}