| 1 | package com.hammurapi.common; |
| 2 | |
| 3 | import java.util.ArrayList; |
| 4 | import java.util.Collection; |
| 5 | import java.util.Collections; |
| 6 | import java.util.Iterator; |
| 7 | |
| 8 | public class SingletonChainingContext<ST> implements MutableContext { |
| 9 | |
| 10 | private Class<ST> type; |
| 11 | private ST service; |
| 12 | private Context chain; |
| 13 | |
| 14 | public SingletonChainingContext(Class<ST> type, ST service, Context chain) { |
| 15 | this.type = type; |
| 16 | this.service = service; |
| 17 | this.chain = chain; |
| 18 | } |
| 19 | |
| 20 | public void bind(String name, Object obj) { |
| 21 | if (chain instanceof MutableContext) { |
| 22 | ((MutableContext) chain).bind(name, obj); |
| 23 | } else { |
| 24 | throw new IllegalStateException("Chain context is not mutable"); |
| 25 | } |
| 26 | } |
| 27 | |
| 28 | public <T> void register(Class<? super T> type, T service) { |
| 29 | if (chain instanceof MutableContext) { |
| 30 | ((MutableContext) chain).register(type, service); |
| 31 | } else { |
| 32 | throw new IllegalStateException("Chain context is not mutable"); |
| 33 | } |
| 34 | } |
| 35 | |
| 36 | public Object unbind(String name) { |
| 37 | if (chain instanceof MutableContext) { |
| 38 | return ((MutableContext) chain).unbind(name); |
| 39 | } else { |
| 40 | throw new IllegalStateException("Chain context is not mutable"); |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | public <T> void unregister(Class<? super T> type, T service) { |
| 45 | if (chain instanceof MutableContext) { |
| 46 | ((MutableContext) chain).unregister(type, service); |
| 47 | } else { |
| 48 | throw new IllegalStateException("Chain context is not mutable"); |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | public Object lookup(String name) { |
| 53 | return chain==null ? null : chain.lookup(name); |
| 54 | } |
| 55 | |
| 56 | @SuppressWarnings("unchecked") |
| 57 | public <T> T lookup(Class<T> serviceClass) { |
| 58 | if (serviceClass.equals(type)) { |
| 59 | return (T) service; |
| 60 | } |
| 61 | |
| 62 | return chain==null ? null : chain.lookup(serviceClass); |
| 63 | } |
| 64 | |
| 65 | @SuppressWarnings("unchecked") |
| 66 | public <T> Iterator<T> lookupAll(Class<T> serviceClass) { |
| 67 | if (serviceClass.equals(type)) { |
| 68 | Collection<T> c = new ArrayList<T>(); |
| 69 | c.add((T) service); |
| 70 | if (chain!=null) { |
| 71 | Iterator<T> it = chain.lookupAll(serviceClass); |
| 72 | while (it.hasNext()) { |
| 73 | c.add(it.next()); |
| 74 | } |
| 75 | } |
| 76 | return c.iterator(); |
| 77 | } |
| 78 | return (Iterator<T>) (chain==null ? Collections.emptyList().iterator() : chain.lookupAll(serviceClass)); |
| 79 | } |
| 80 | |
| 81 | } |