cn.hutool.core.map.TableMap Maven / Gradle / Ivy
package cn.hutool.core.map;
import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.collection.ListUtil;
import cn.hutool.core.util.ObjectUtil;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* 可重复键和值的Map
* 通过键值单独建立List方式，使键值对一一对应，实现正向和反向两种查找
* 无论是正向还是反向，都是遍历列表查找过程，相比标准的HashMap要慢，数据越多越慢
*
* @param 键类型
* @param 值类型
* @author looly
*/
public class TableMap implements Map, Iterable>, Serializable {
private static final long serialVersionUID = 1L;
private static final int DEFAULT_CAPACITY = 10;
private final List keys;
private final List values;
/**
* 构造
*/
public TableMap() {
this(DEFAULT_CAPACITY);
}
/**
* 构造
*
* @param size 初始容量
*/
public TableMap(int size) {
this.keys = new ArrayList<>(size);
this.values = new ArrayList<>(size);
}
/**
* 构造
*
* @param keys 键列表
* @param values 值列表
*/
public TableMap(K[] keys, V[] values) {
this.keys = CollUtil.toList(keys);
this.values = CollUtil.toList(values);
}
@Override
public int size() {
return keys.size();
}
@Override
public boolean isEmpty() {
return CollUtil.isEmpty(keys);
}
@Override
public boolean containsKey(Object key) {
//noinspection SuspiciousMethodCalls
return keys.contains(key);
}
@Override
public boolean containsValue(Object value) {
//noinspection SuspiciousMethodCalls
return values.contains(value);
}
@Override
public V get(Object key) {
//noinspection SuspiciousMethodCalls
final int index = keys.indexOf(key);
if (index > -1 && index < values.size()) {
return values.get(index);
}
return null;
}
/**
* 根据value获得对应的key，只返回找到的第一个value对应的key值
*
* @param value 值
* @return 键
* @since 5.3.3
*/
public K getKey(V value) {
final int index = values.indexOf(value);
if (index > -1 && index < keys.size()) {
return keys.get(index);
}
return null;
}
/**
* 获取指定key对应的所有值
*
* @param key 键
* @return 值列表
* @since 5.2.5
*/
public List getValues(K key) {
return CollUtil.getAny(
this.values,
ListUtil.indexOfAll(this.keys, (ele) -> ObjectUtil.equal(ele, key))
);
}
/**
* 获取指定value对应的所有key
*
* @param value 值
* @return 值列表
* @since 5.2.5
*/
public List getKeys(V value) {
return CollUtil.getAny(
this.keys,
ListUtil.indexOfAll(this.values, (ele) -> ObjectUtil.equal(ele, value))
);
}
@Override
public V put(K key, V value) {
keys.add(key);
values.add(value);
return null;
}
@Override
public V remove(Object key) {
//noinspection SuspiciousMethodCalls
int index = keys.indexOf(key);
if (index > -1) {
keys.remove(index);
if (index < values.size()) {
values.remove(index);
}
}
return null;
}
@Override
public void putAll(Map m) {
for (Map.Entry entry : m.entrySet()) {
this.put(entry.getKey(), entry.getValue());
}
}
@Override
public void clear() {
keys.clear();
values.clear();
}
@Override
public Set keySet() {
return new HashSet<>(this.keys);
}
/**
* 获取所有键，可重复，不可修改
*
* @return 键列表
* @since 5.8.0
*/
public List keys() {
return Collections.unmodifiableList(this.keys);
}
@Override
public Collection values() {
return Collections.unmodifiableList(this.values);
}
@Override
public Set> entrySet() {
final Set> hashSet = new LinkedHashSet<>();
for (int i = 0; i < size(); i++) {
hashSet.add(MapUtil.entry(keys.get(i), values.get(i)));
}
return hashSet;
}
@Override
public Iterator> iterator() {
return new Iterator>() {
private final Iterator keysIter = keys.iterator();
private final Iterator valuesIter = values.iterator();
@Override
public boolean hasNext() {
return keysIter.hasNext() && valuesIter.hasNext();
}
@Override
public Map.Entry next() {
return MapUtil.entry(keysIter.next(), valuesIter.next());
}
@Override
public void remove() {
keysIter.remove();
valuesIter.remove();
}
};
}
@Override
public String toString() {
return "TableMap{" +
"keys=" + keys +
", values=" + values +
'}';
}
}