Java tutorial
/* * Minecraft Forge * Copyright (c) 2016. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation version 2.1 * of the License. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ package net.minecraftforge.registries; import java.util.BitSet; import java.util.Collection; import java.util.Collections; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Map.Entry; import javax.annotation.Nullable; import org.apache.commons.lang3.Validate; import java.util.Set; import com.google.common.base.Preconditions; import com.google.common.collect.ArrayListMultimap; import com.google.common.collect.BiMap; import com.google.common.collect.HashBiMap; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import com.google.common.collect.Multimap; import com.google.common.collect.Sets; import net.minecraft.util.ResourceLocation; import net.minecraftforge.event.RegistryEvent; import net.minecraftforge.event.RegistryEvent.MissingMappings; import net.minecraftforge.fml.common.FMLContainer; import net.minecraftforge.fml.common.FMLLog; import net.minecraftforge.fml.common.InjectedModContainer; import net.minecraftforge.fml.common.Loader; import net.minecraftforge.fml.common.ModContainer; import net.minecraftforge.fml.relauncher.ReflectionHelper; import net.minecraftforge.registries.IForgeRegistry.AddCallback; import net.minecraftforge.registries.IForgeRegistry.ClearCallback; import net.minecraftforge.registries.IForgeRegistry.CreateCallback; import net.minecraftforge.registries.IForgeRegistry.DummyFactory; public class ForgeRegistry<V extends IForgeRegistryEntry<V>> implements IForgeRegistryInternal<V>, IForgeRegistryModifiable<V> { public static final boolean DEBUG = Boolean .parseBoolean(System.getProperty("forge.debugRegistryEntries", "false")); private final RegistryManager stage; private final BiMap<Integer, V> ids = HashBiMap.create(); private final BiMap<ResourceLocation, V> names = HashBiMap.create(); private final Class<V> superType; private final Map<ResourceLocation, ResourceLocation> aliases = Maps.newHashMap(); final Map<ResourceLocation, ?> slaves = Maps.newHashMap(); private final ResourceLocation defaultKey; private final CreateCallback<V> create; private final AddCallback<V> add; private final ClearCallback<V> clear; private final BitSet availabilityMap; private final Set<ResourceLocation> dummies = Sets.newHashSet(); private final Set<Integer> blocked = Sets.newHashSet(); private final Multimap<ResourceLocation, V> overrides = ArrayListMultimap.create(); private final BiMap<OverrideOwner, V> owners = HashBiMap.create(); private final DummyFactory<V> dummyFactory; private final boolean isDelegated; private final int min; private final int max; private final boolean allowOverrides; private final boolean isModifiable; private V defaultValue = null; boolean isFrozen = false; ForgeRegistry(Class<V> superType, ResourceLocation defaultKey, int min, int max, @Nullable CreateCallback<V> create, @Nullable AddCallback<V> add, @Nullable ClearCallback<V> clear, RegistryManager stage, boolean allowOverrides, boolean isModifiable, @Nullable DummyFactory<V> dummyFactory) { this.stage = stage; this.superType = superType; this.defaultKey = defaultKey; this.min = min; this.max = max; this.availabilityMap = new BitSet(Math.min(max + 1, 0x0FFF)); this.create = create; this.add = add; this.clear = clear; this.isDelegated = IForgeRegistryEntry.Impl.class.isAssignableFrom(superType); //TODO: Make this IDelegatedRegistryEntry? this.allowOverrides = allowOverrides; this.isModifiable = isModifiable; this.dummyFactory = dummyFactory; if (this.create != null) this.create.onCreate(this, stage); } @Override public void register(V value) { add(-1, value); } @Override public Iterator<V> iterator() { return new Iterator<V>() { int cur = -1; V next = null; { next(); } @Override public boolean hasNext() { return next != null; } @Override public V next() { V ret = next; do { cur = availabilityMap.nextSetBit(cur + 1); next = ids.get(cur); } while (next == null && cur != -1); // nextSetBit returns -1 when none is found return ret; } //TODO add remove support? }; } @Override public Class<V> getRegistrySuperType() { return superType; } @Override public void registerAll(@SuppressWarnings("unchecked") V... values) { for (V value : values) register(value); } @Override public boolean containsKey(ResourceLocation key) { while (key != null) { if (this.names.containsKey(key)) return true; key = this.aliases.get(key); } return false; } @Override public boolean containsValue(V value) { return this.names.containsValue(value); } @Override public V getValue(ResourceLocation key) { V ret = this.names.get(key); key = this.aliases.get(key); while (ret == null && key != null) { ret = this.names.get(key); key = this.aliases.get(key); } return ret == null ? this.defaultValue : ret; } @Override public ResourceLocation getKey(V value) { return this.names.inverse().get(value); } @Override public Set<ResourceLocation> getKeys() { return ImmutableSet.copyOf(this.names.keySet()); } @Override public List<V> getValues() { return ImmutableList.copyOf(this.names.values()); } @Override public Set<Entry<ResourceLocation, V>> getEntries() { return ImmutableSet.copyOf(this.names.entrySet()); } @SuppressWarnings("unchecked") @Override public <T> T getSlaveMap(ResourceLocation name, Class<T> type) { return (T) this.slaves.get(name); } @SuppressWarnings("unchecked") @Override public void setSlaveMap(ResourceLocation name, Object obj) { ((Map<ResourceLocation, Object>) this.slaves).put(name, obj); } public int getID(V value) { Integer ret = this.ids.inverse().get(value); if (ret == null && this.defaultValue != null) ret = this.ids.inverse().get(this.defaultValue); return ret == null ? -1 : ret.intValue(); } public int getID(ResourceLocation name) { return getID(this.names.get(name)); } private int getIDRaw(V value) { Integer ret = this.ids.inverse().get(value); return ret == null ? -1 : ret.intValue(); } private int getIDRaw(ResourceLocation name) { return getIDRaw(this.names.get(name)); } public V getValue(int id) { V ret = this.ids.get(id); return ret == null ? this.defaultValue : ret; } void validateKey() { if (this.defaultKey != null) Validate.notNull(this.defaultValue, "Missing default of ForgeRegistry: " + this.defaultKey + " Type: " + this.superType); } ForgeRegistry<V> copy(RegistryManager stage) { return new ForgeRegistry<V>(superType, defaultKey, min, max, create, add, clear, stage, allowOverrides, isModifiable, dummyFactory); } int add(int id, V value) { ModContainer mc = Loader.instance().activeModContainer(); String owner = mc == null || (mc instanceof InjectedModContainer && ((InjectedModContainer) mc).wrappedContainer instanceof FMLContainer) ? null : mc.getModId().toLowerCase(); return add(id, value, owner); } int add(int id, V value, String owner) { ResourceLocation key = value == null ? null : value.getRegistryName(); Preconditions.checkNotNull(key, "Can't use a null-name for the registry, object %s.", value); Preconditions.checkNotNull(value, "Can't add null-object to the registry, name %s.", key); int idToUse = id; if (idToUse < 0 || availabilityMap.get(idToUse)) idToUse = availabilityMap.nextClearBit(min); if (idToUse > max) throw new RuntimeException(String.format("Invalid id %d - maximum id range exceeded.", idToUse)); V oldEntry = getRaw(key); if (oldEntry == value) // already registered, return prev registration's id { FMLLog.bigWarning("Registry {}: The object {} has been registered twice for the same name {}.", this.superType.getSimpleName(), value, key); return this.getID(value); } if (oldEntry != null) // duplicate name { if (!this.allowOverrides) throw new IllegalArgumentException(String .format("The name %s has been registered twice, for %s and %s.", key, getRaw(key), value)); if (owner == null) throw new IllegalStateException( String.format("Could not determine owner for the override on %s. Value: %s", key, value)); if (DEBUG) FMLLog.log.debug("Registry {} Override: {} {} -> {}", this.superType.getSimpleName(), key, oldEntry, value); idToUse = this.getID(oldEntry); } Integer foundId = this.ids.inverse().get(value); //Is this ever possible to trigger with otherThing being different? if (foundId != null) { V otherThing = this.ids.get(foundId); throw new IllegalArgumentException(String.format( "The object %s{%x} has been registered twice, using the names %s and %s. (Other object at this id is %s{%x})", value, System.identityHashCode(value), getKey(value), key, otherThing, System.identityHashCode(otherThing))); } if (isLocked()) throw new IllegalStateException( String.format("The object %s (name %s) is being added too late.", value, key)); if (defaultKey != null && defaultKey.equals(key)) { if (this.defaultValue != null) throw new IllegalStateException(String.format( "Attemped to override already set default value. This is not allowed: The object %s (name %s)", value, key)); this.defaultValue = value; } this.names.put(key, value); this.ids.put(idToUse, value); this.availabilityMap.set(idToUse); this.owners.put(new OverrideOwner(owner == null ? key.getResourceDomain() : owner, key), value); if (isDelegated) { getDelegate(value).setName(key); if (oldEntry != null) { if (!this.overrides.get(key).contains(oldEntry)) this.overrides.put(key, oldEntry); this.overrides.get(key).remove(value); if (this.stage == RegistryManager.ACTIVE) getDelegate(oldEntry).changeReference(value); } } if (this.add != null) this.add.onAdd(this, this.stage, idToUse, value, oldEntry); if (this.dummies.remove(key) && DEBUG) FMLLog.log.debug("Registry {} Dummy Remove: {}", this.superType.getSimpleName(), key); if (DEBUG) FMLLog.log.trace("Registry {} add: {} {} {} (req. id {})", this.superType.getSimpleName(), key, idToUse, value, id); return idToUse; } private V getRaw(ResourceLocation key) { V ret = this.names.get(key); key = this.aliases.get(key); while (ret == null && key != null) { ret = this.names.get(key); key = this.aliases.get(key); } return ret; } @Deprecated //Public for ByteByfUtils only! public V getRaw(int id) { return this.ids.get(id); } void addAlias(ResourceLocation from, ResourceLocation to) { if (this.isLocked()) throw new IllegalStateException( String.format("Attempted to register the alias %s -> %s to late", from, to)); this.aliases.put(from, to); if (DEBUG) FMLLog.log.trace("Registry {} alias: {} -> {}", this.superType.getSimpleName(), from, to); } void addDummy(ResourceLocation key) { if (this.isLocked()) throw new IllegalStateException(String.format("Attempted to register the dummy %s to late", key)); this.dummies.add(key); if (DEBUG) FMLLog.log.trace("Registry {} dummy: {}", this.superType.getSimpleName(), key); } private RegistryDelegate<V> getDelegate(V thing) { if (isDelegated) return (RegistryDelegate<V>) ((IForgeRegistryEntry.Impl<V>) thing).delegate; else throw new IllegalStateException("Tried to get existing delegate from registry that is not delegated."); } void resetDelegates() { if (!this.isDelegated) return; for (V value : this) getDelegate(value).changeReference(value); for (V value : this.overrides.values()) getDelegate(value).changeReference(value); } V getDefault() { return this.defaultValue; } boolean isDummied(ResourceLocation key) { return this.dummies.contains(key); } void validateContent(ResourceLocation registryName) { try { ReflectionHelper.findMethod(BitSet.class, "trimToSize", null).invoke(this.availabilityMap); } catch (Exception e) { //We don't care... Just a micro-optimization } for (V obj : this) { int id = getID(obj); ResourceLocation name = getKey(obj); // name lookup failed -> obj is not in the obj<->name map if (name == null) throw new IllegalStateException(String .format("Registry entry for %s %s, id %d, doesn't yield a name.", registryName, obj, id)); // id is too high if (id > max) throw new IllegalStateException( String.format("Registry entry for %s %s, name %s uses the too large id %d.", registryName, obj, name, id)); // id -> obj lookup is inconsistent if (getValue(id) != obj) throw new IllegalStateException( String.format("Registry entry for id %d, name %s, doesn't yield the expected %s %s.", id, name, registryName, obj)); // name -> obj lookup is inconsistent if (getValue(name) != obj) throw new IllegalStateException( String.format("Registry entry for name %s, id %d, doesn't yield the expected %s %s.", name, id, registryName, obj)); // name -> id lookup is inconsistent if (getID(name) != id) throw new IllegalStateException( String.format("Registry entry for name %s doesn't yield the expected id %d.", name, id)); /* // entry is blocked, thus should be empty if (blockedIds.contains(id)) throw new IllegalStateException(String.format("Registry entry for %s %s, id %d, name %s, marked as dangling.", registryName, obj, id, name)); */ } } void sync(ResourceLocation name, ForgeRegistry<V> from) { if (DEBUG) FMLLog.log.debug("Registry {} Sync: {} -> {}", this.superType.getSimpleName(), this.stage.getName(), from.stage.getName()); if (this == from) throw new IllegalArgumentException("WTF We are the same!?!?!"); if (from.superType != this.superType) throw new IllegalArgumentException("Attempted to copy to incompatible registry: " + name + " " + from.superType + " -> " + this.superType); this.isFrozen = false; if (this.clear != null) this.clear.onClear(this, stage); /* -- Should never need to be copied this.defaultKey = from.defaultKey; this.max = from.max; this.min = from.min; */ this.aliases.clear(); from.aliases.forEach(this::addAlias); this.ids.clear(); this.names.clear(); this.availabilityMap.clear(0, this.availabilityMap.length()); this.defaultValue = null; this.overrides.clear(); this.owners.clear(); boolean errored = false; for (Entry<ResourceLocation, V> entry : from.names.entrySet()) { List<V> overrides = Lists.newArrayList(from.overrides.get(entry.getKey())); int id = from.getID(entry.getKey()); if (overrides.isEmpty()) { int realId = add(id, entry.getValue()); if (id != realId && id != -1) { FMLLog.log.warn( "Registry {}: Object did not get ID it asked for. Name: {} Expected: {} Got: {}", this.superType.getSimpleName(), entry.getKey(), id, realId); errored = true; } } else { overrides.add(entry.getValue()); for (V value : overrides) { OverrideOwner owner = from.owners.inverse().get(value); if (owner == null) { FMLLog.log.warn( "Registry {}: Override did not have an associated owner object. Name: {} Value: {}", this.superType.getSimpleName(), entry.getKey(), value); errored = true; continue; } int realId = add(id, value, owner.owner); if (id != realId && id != -1) { FMLLog.log.warn( "Registry {}: Object did not get ID it asked for. Name: {} Expected: {} Got: {}", this.superType.getSimpleName(), entry.getKey(), id, realId); errored = true; } } } } //Needs to be below add so that dummies are persisted this.dummies.clear(); from.dummies.forEach(this::addDummy); if (errored) throw new RuntimeException( "One of more entry values did not copy to the correct id. Check log for details!"); } @Override public void clear() { if (!this.isModifiable) throw new UnsupportedOperationException("Attempted to clear a non-modifiable Forge Registry"); if (this.isLocked()) throw new IllegalStateException("Attempted to clear the registry to late."); if (this.clear != null) this.clear.onClear(this, stage); this.aliases.clear(); this.dummies.clear(); this.ids.clear(); this.names.clear(); this.availabilityMap.clear(0, this.availabilityMap.length()); } @Override public V remove(ResourceLocation key) { if (!this.isModifiable) throw new UnsupportedOperationException("Attempted to remove from a non-modifiable Forge Registry"); if (this.isLocked()) throw new IllegalStateException("Attempted to remove from the registry to late."); V value = this.names.remove(key); if (value != null) { Integer id = this.ids.inverse().remove(value); if (id == null) throw new IllegalStateException("Removed a entry that did not have an associated id: " + key + " " + value.toString() + " This should never happen unless hackery!"); } return value; } void block(int id) { this.blocked.add(id); this.availabilityMap.set(id); } @Override public boolean isLocked() { return this.isFrozen; } /** * Used to control the times where people can modify this registry. * Users should only ever register things in the Register<?> events! */ public void freeze() { this.isFrozen = true; } public void unfreeze() { this.isFrozen = false; } RegistryEvent.Register<V> getRegisterEvent(ResourceLocation name) { return new RegistryEvent.Register<V>(name, this); } void dump(ResourceLocation name) { List<Integer> ids = Lists.newArrayList(); getKeys().forEach(n -> ids.add(getID(n))); Collections.sort(ids); FMLLog.log.trace("Registry Name : {}", name); ids.forEach(id -> FMLLog.log.trace(" Registry: {} {} {}", id, getKey(getValue(id)), getValue(id))); } public void loadIds(Map<ResourceLocation, Integer> ids, Map<ResourceLocation, String> overrides, Map<ResourceLocation, Integer> missing, Map<ResourceLocation, Integer[]> remapped, ForgeRegistry<V> old, ResourceLocation name) { Map<ResourceLocation, String> ovs = Maps.newHashMap(overrides); for (Map.Entry<ResourceLocation, Integer> entry : ids.entrySet()) { ResourceLocation itemName = entry.getKey(); int newId = entry.getValue(); int currId = old.getIDRaw(itemName); if (currId == -1) { FMLLog.log.info("Registry {}: Found a missing id from the world {}", this.superType.getSimpleName(), itemName); missing.put(itemName, newId); continue; // no block/item -> nothing to add } else if (currId != newId) { FMLLog.log.debug("Registry {}: Fixed {} id mismatch {}: {} (init) -> {} (map).", this.superType.getSimpleName(), name, itemName, currId, newId); remapped.put(itemName, new Integer[] { currId, newId }); } V obj = old.getRaw(itemName); Preconditions.checkState(obj != null, "objectKey has an ID but no object. Reflection/ASM hackery? Registry bug?"); List<V> lst = Lists.newArrayList(old.overrides.get(itemName)); String primaryName = null; if (old.overrides.containsKey(itemName)) { if (!overrides.containsKey(itemName)) { lst.add(obj); obj = old.overrides.get(itemName).iterator().next(); //Get the first one in the list, Which should be the first one registered primaryName = old.owners.inverse().get(obj).owner; } else primaryName = overrides.get(itemName); } for (V value : lst) { OverrideOwner owner = old.owners.inverse().get(value); if (owner == null) { FMLLog.log.warn( "Registry {}: Override did not have an associated owner object. Name: {} Value: {}", this.superType.getSimpleName(), entry.getKey(), value); continue; } if (primaryName.equals(owner)) continue; int realId = add(newId, value, owner.owner); if (newId != realId) FMLLog.log.warn( "Registry {}: Object did not get ID it asked for. Name: {} Expected: {} Got: {}", this.superType.getSimpleName(), entry.getKey(), newId, realId); } int realId = add(newId, obj, primaryName == null ? itemName.getResourceDomain() : primaryName); if (realId != newId) FMLLog.log.warn("Registry {}: Object did not get ID it asked for. Name: {} Expected: {} Got: {}", this.superType.getSimpleName(), entry.getKey(), newId, realId); ovs.remove(itemName); } for (Map.Entry<ResourceLocation, String> entry : ovs.entrySet()) { ResourceLocation itemName = entry.getKey(); String owner = entry.getValue(); String current = this.owners.inverse().get(this.getRaw(itemName)).owner; if (!owner.equals(current)) { V _new = this.owners.get(new OverrideOwner(owner, itemName)); if (_new == null) { FMLLog.log.warn("Registry {}: Skipping override for {}, Unknown owner {}", this.superType.getSimpleName(), itemName, owner); continue; } FMLLog.log.info("Registry {}: Activating override {} for {}", this.superType.getSimpleName(), owner, itemName); int newId = this.getID(itemName); int realId = this.add(newId, _new, owner); if (newId != realId) FMLLog.log.warn( "Registry {}: Object did not get ID it asked for. Name: {} Expected: {} Got: {}", this.superType.getSimpleName(), entry.getKey(), newId, realId); } } } boolean markDummy(ResourceLocation key, int id) { if (this.dummyFactory == null) return false; V dummy = this.dummyFactory.createDummy(key); if (DEBUG) FMLLog.log.trace("Registry Dummy Add: {} {} -> {}", key, id, dummy); //It was blocked before so we need to unset the blocking map this.availabilityMap.clear(id); int realId = this.add(id, dummy); if (realId != id) FMLLog.log.warn("Registry {}: Object did not get ID it asked for. Name: {} Expected: {} Got: {}", this.superType.getSimpleName(), key, id, realId); this.dummies.add(key); return true; } //Public for tests public Snapshot makeSnapshot() { Snapshot ret = new Snapshot(); this.ids.forEach((id, value) -> ret.ids.put(getKey(value), id)); ret.aliases.putAll(this.aliases); ret.blocked.addAll(this.blocked); ret.dummied.addAll(this.dummies); ret.overrides.putAll(getOverrideOwners()); return ret; } Map<ResourceLocation, String> getOverrideOwners() { Map<ResourceLocation, String> ret = Maps.newHashMap(); for (ResourceLocation key : this.overrides.keySet()) { V obj = this.names.get(key); OverrideOwner owner = this.owners.inverse().get(obj); if (owner == null && DEBUG) FMLLog.log.debug("Registry {} {}: Invalid override {} {}", this.superType.getSimpleName(), this.stage.getName(), key, obj); ret.put(key, owner.owner); } return ret; } public static class Snapshot { public final Map<ResourceLocation, Integer> ids = Maps.newHashMap(); public final Map<ResourceLocation, ResourceLocation> aliases = Maps.newHashMap(); public final Set<Integer> blocked = Sets.newHashSet(); public final Set<ResourceLocation> dummied = Sets.newHashSet(); public final Map<ResourceLocation, String> overrides = Maps.newHashMap(); } public MissingMappings<?> getMissingEvent(ResourceLocation name, Map<ResourceLocation, Integer> map) { List<MissingMappings.Mapping<V>> lst = Lists.newArrayList(); ForgeRegistry<V> pool = RegistryManager.ACTIVE.getRegistry(name); map.forEach((rl, id) -> lst.add(new MissingMappings.Mapping<V>(this, pool, rl, id))); return new MissingMappings<V>(name, this, lst); } void processMissingEvent(ResourceLocation name, ForgeRegistry<V> pool, List<MissingMappings.Mapping<V>> mappings, Map<ResourceLocation, Integer> missing, Map<ResourceLocation, Integer[]> remaps, Collection<ResourceLocation> defaulted, Collection<ResourceLocation> failed) { FMLLog.log.debug("Processing missing event for {}:", name); int ignored = 0; for (MissingMappings.Mapping<V> remap : mappings) { MissingMappings.Action action = remap.getAction(); if (action == MissingMappings.Action.REMAP) { // entry re-mapped, finish the registration with the new name/object, but the old id int currId = getID(remap.getTarget()); ResourceLocation newName = pool.getKey(remap.getTarget()); FMLLog.log.debug(" Remapping {} -> {}.", remap.key, newName); missing.remove(remap.key); //I don't think this will work, but I dont think it ever worked.. the item is already in the map with a different id... we want to fix that.. int realId = this.add(remap.id, remap.getTarget()); if (realId != remap.id) FMLLog.log.warn( "Registered object did not get ID it asked for. Name: {} Type: {} Expected: {} Got: {}", newName, this.getRegistrySuperType(), remap.id, realId); this.addAlias(remap.key, newName); if (currId != realId) { FMLLog.log.info(" Fixed id mismatch {}: {} (init) -> {} (map).", newName, currId, realId); remaps.put(newName, new Integer[] { currId, realId }); } } else { // block item missing, warn as requested and block the id if (action == MissingMappings.Action.DEFAULT) { defaulted.add(remap.key); } else if (action == MissingMappings.Action.IGNORE) { FMLLog.log.debug(" Ignoring {}", remap.key); ignored++; } else if (action == MissingMappings.Action.FAIL) { FMLLog.log.debug(" Failing {}!", remap.key); failed.add(remap.key); } else if (action == MissingMappings.Action.WARN) { FMLLog.log.warn(" {} may cause world breakage!", remap.key); } this.block(remap.id); } } if (failed.isEmpty() && ignored > 0) FMLLog.log.debug("There were {} missing mappings that have been ignored", ignored); } private static class OverrideOwner { final String owner; final ResourceLocation key; private OverrideOwner(String owner, ResourceLocation key) { this.owner = owner; this.key = key; } public boolean equals(Object o) { if (this == o) return true; if (!(o instanceof OverrideOwner)) return false; OverrideOwner oo = (OverrideOwner) o; return this.owner.equals(oo.owner) && this.key.equals(oo.key); } public int hashCode() { return 31 * this.key.hashCode() + this.owner.hashCode(); } } }