com.maxifier.mxcache.impl.instanceprovider.DefaultInstanceProvider Maven / Gradle / Ivy

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/*
 * Copyright (c) 2008-2014 Maxifier Ltd. All Rights Reserved.
 */
package com.maxifier.mxcache.impl.instanceprovider;

import com.maxifier.mxcache.InstanceProvider;
import com.maxifier.mxcache.NoSuchInstanceException;
import gnu.trove.map.hash.THashMap;

import javax.annotation.Nonnull;

import java.util.Collections;
import java.util.Map;

/**
 * @author Alexander Kochurov ([email protected])
 */
public final class DefaultInstanceProvider implements InstanceProvider {
    private static final DefaultInstanceProvider INSTANCE = new DefaultInstanceProvider();

    private final Map registry = Collections.synchronizedMap(new THashMap());

    private DefaultInstanceProvider() {}

    public static DefaultInstanceProvider getInstance() {
        return INSTANCE;
    }

    public  Binder bind(final Class t) {
        return new BinderImpl(this, registry, t);
    }

    public void clearBinding(Class cls) {
        registry.remove(cls);
    }

    @Nonnull
    @SuppressWarnings({ "unchecked" })
    @Override
    public  T forClass(@Nonnull Class cls) {
        Provider provider = registry.get(cls);
        if (provider == null) {
            return createInstance(cls);
        }
        return (T) provider.get();
    }

    private static  T createInstance(@Nonnull Class cls) {
        try {
            return cls.newInstance();
        } catch (InstantiationException e) {
            throw new NoSuchInstanceException(e);
        } catch (IllegalAccessException e) {
            throw new NoSuchInstanceException(e);
        }
    }

}