com.sun.hk2.component.ScopedInhabitant Maven / Gradle / Ivy
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package com.sun.hk2.component;
import org.jvnet.hk2.component.Creator;
import org.jvnet.hk2.component.Scope;
import org.jvnet.hk2.component.Inhabitant;
import org.jvnet.hk2.tracing.TracingThreadLocal;
import org.jvnet.hk2.tracing.TracingUtilities;
/**
* @author Kohsuke Kawaguchi
*/
public class ScopedInhabitant extends AbstractCreatorInhabitantImpl {
private final Scope scope;
public ScopedInhabitant(Creator creator, Scope scope) {
super(creator);
this.scope = scope;
}
@SuppressWarnings("unchecked")
public T get(Inhabitant onBehalfOf) {
try {
if (TracingUtilities.isEnabled())
TracingThreadLocal.get().push(this);
ScopeInstance store = scope.current();
// scope is extension point, so beware for the broken implementation
assert store!=null : scope+" returned null";
T o = store.get(this);
if(o==null) {
synchronized(this) {
// to avoid creating multiple objects into the same scope, lock this object
// verify no one else created one in the mean time
o = store.get(this);
if(o==null) {
o = creator.get(onBehalfOf);
store.put(this,o);
}
}
}
assert o!=null;
return o;
} finally {
if (TracingUtilities.isEnabled())
TracingThreadLocal.get().pop();
}
}
public boolean isInstantiated() {
return scope.current().get(this)!=null;
}
public void release() {
// noop
}
}