| 1 | package com.hammurapi.common; |
| 2 | |
| 3 | import java.util.Iterator; |
| 4 | import java.util.Map; |
| 5 | import java.util.ServiceLoader; |
| 6 | |
| 7 | /** |
| 8 | * Default context uses ServiceLoader to find services in |
| 9 | * a given classloader and map of bindings. |
| 10 | * @author Pavel Vlasov |
| 11 | * |
| 12 | */ |
| 13 | public class DefaultContext implements Context { |
| 14 | |
| 15 | private ClassLoader classLoader; |
| 16 | private Map<String, Object> bindings; |
| 17 | |
| 18 | /** |
| 19 | * @param classLoader ClassLoader for services. Can be null. |
| 20 | * @param bindings Name bindings. Can be null. |
| 21 | */ |
| 22 | public DefaultContext(ClassLoader classLoader, Map<String, Object> bindings) { |
| 23 | this.classLoader = classLoader==null ? this.getClass().getClassLoader() : classLoader; |
| 24 | this.bindings = bindings; |
| 25 | } |
| 26 | |
| 27 | public Object lookup(String name) { |
| 28 | return bindings==null ? null : bindings.get(name); |
| 29 | } |
| 30 | |
| 31 | public <T> T lookup(Class<T> serviceClass) { |
| 32 | ServiceLoader<T> sl = ServiceLoader.load(serviceClass, classLoader); |
| 33 | Iterator<T> sit = sl.iterator(); |
| 34 | return sit.hasNext() ? sit.next() : null; |
| 35 | } |
| 36 | |
| 37 | public <T> Iterator<T> lookupAll(Class<T> serviceClass) { |
| 38 | ServiceLoader<T> sl = ServiceLoader.load(serviceClass, classLoader); |
| 39 | return sl.iterator(); |
| 40 | } |
| 41 | |
| 42 | } |