!87 提供一个自带默认值的Map

Merge pull request !87 from Ease/v5-dev

hutool-core/src/main/java/cn/hutool/core/map/TolerantMap.java

@@ -0,0 +1,203 @@
+package cn.hutool.core.map;
+
+import cn.hutool.core.util.ObjectUtil;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+import java.util.*;
+import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+
+/**
+ * 一个可以提供默认值的Map
+ *
+ * @author pantao
+ * @since 2020/1/3
+ */
+public class TolerantMap<K, V> extends AbstractMap<K, V> implements Map<K, V>, Cloneable, Serializable {
+
+    private static final long serialVersionUID = -4158133823263496197L;
+
+    private transient Map<K, V> map;
+
+    private transient V defaultValue;
+
+    public TolerantMap(V defaultValue) {
+        this(new HashMap<>(), defaultValue);
+    }
+
+    public TolerantMap(int initialCapacity, float loadFactor, V defaultValue) {
+        this(new HashMap<>(initialCapacity, loadFactor), defaultValue);
+    }
+
+    public TolerantMap(int initialCapacity, V defaultValue) {
+        this(new HashMap<>(initialCapacity), defaultValue);
+    }
+
+    public TolerantMap(Map<K, V> map, V defaultValue) {
+        this.map = map;
+        this.defaultValue = defaultValue;
+    }
+
+    public static <K, V> TolerantMap<K, V> of(Map<K, V> map, V defaultValue) {
+        return new TolerantMap<>(map, defaultValue);
+    }
+
+    @Override
+    public int size() {
+        return map.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return map.isEmpty();
+    }
+
+    @Override
+    public boolean containsValue(Object value) {
+        return map.containsValue(value);
+    }
+
+    @Override
+    public boolean containsKey(Object key) {
+        return map.containsKey(key);
+    }
+
+    @Override
+    public V get(Object key) {
+        return getOrDefault(key, defaultValue);
+    }
+
+    @Override
+    public V put(K key, V value) {
+        return map.put(key, value);
+    }
+
+    @Override
+    public V remove(Object key) {
+        return map.remove(key);
+    }
+
+    @Override
+    public void putAll(Map<? extends K, ? extends V> m) {
+        map.putAll(m);
+    }
+
+    @Override
+    public void clear() {
+        map.clear();
+    }
+
+    @Override
+    public Set<K> keySet() {
+        return map.keySet();
+    }
+
+    @Override
+    public Collection<V> values() {
+        return map.values();
+    }
+
+    @Override
+    public Set<Entry<K, V>> entrySet() {
+        return map.entrySet();
+    }
+
+    @Override
+    public V getOrDefault(Object key, V defaultValue) {
+        return map.getOrDefault(key, defaultValue);
+    }
+
+    @Override
+    public void forEach(BiConsumer<? super K, ? super V> action) {
+        map.forEach(action);
+    }
+
+    @Override
+    public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
+        map.replaceAll(function);
+    }
+
+    @Override
+    public V putIfAbsent(K key, V value) {
+        return map.putIfAbsent(key, value);
+    }
+
+    @Override
+    public boolean remove(Object key, Object value) {
+        return map.remove(key, value);
+    }
+
+    @Override
+    public boolean replace(K key, V oldValue, V newValue) {
+        return map.replace(key, oldValue, newValue);
+    }
+
+    @Override
+    public V replace(K key, V value) {
+        return map.replace(key, value);
+    }
+
+    @Override
+    public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
+        return map.computeIfAbsent(key, mappingFunction);
+    }
+
+    @Override
+    public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
+        return map.computeIfPresent(key, remappingFunction);
+    }
+
+    @Override
+    public V compute(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
+        return map.compute(key, remappingFunction);
+    }
+
+    @Override
+    public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
+        return map.merge(key, value, remappingFunction);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        if (!super.equals(o)) {
+            return false;
+        }
+        TolerantMap<?, ?> that = (TolerantMap<?, ?>) o;
+        return map.equals(that.map) && Objects.equals(defaultValue, that.defaultValue);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(map, defaultValue);
+    }
+
+    @Override
+    public String toString() {
+        return "TolerantMap{" + "map=" + map + ", defaultValue=" + defaultValue + '}';
+    }
+
+    private void writeObject(ObjectOutputStream s) throws IOException {
+        s.writeObject(ObjectUtil.serialize(map));
+        s.writeObject(ObjectUtil.serialize(defaultValue));
+    }
+
+    private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
+        map = ObjectUtil.deserialize((byte[]) s.readObject());
+        defaultValue = ObjectUtil.deserialize((byte[]) s.readObject());
+    }
+
+    @Override
+    protected Object clone() throws CloneNotSupportedException {
+        return super.clone();
+    }
+}

hutool-core/src/test/java/cn/hutool/core/map/TolerantMapTest.java

@@ -0,0 +1,40 @@
+package cn.hutool.core.map;
+
+import cn.hutool.core.util.ObjectUtil;
+import cn.hutool.core.util.RandomUtil;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.HashMap;
+
+public class TolerantMapTest {
+
+    private final TolerantMap<String, String> map = TolerantMap.of(new HashMap<>(), "default");
+
+    @Before
+    public void before() {
+        map.put("monday", "星期一");
+        map.put("tuesday", "星期二");
+    }
+
+    @Test
+    public void testSerialize() {
+        byte[] bytes = ObjectUtil.serialize(map);
+        TolerantMap<String, String> serializedMap = ObjectUtil.deserialize(bytes);
+        assert serializedMap != map;
+        assert map.equals(serializedMap);
+    }
+
+    @Test
+    public void testClone() {
+        TolerantMap<String, String> clonedMap = ObjectUtil.clone(map);
+        assert clonedMap != map;
+        assert map.equals(clonedMap);
+    }
+
+    @Test
+    public void testGet() {
+        assert "星期二".equals(map.get("tuesday"));
+        assert "default".equals(map.get(RandomUtil.randomString(6)));
+    }
+}