com.google.inject.internal.BindingImpl Maven / Gradle / Ivy

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package com.google.inject.internal;

import com.google.common.base.MoreObjects;
import com.google.inject.Binding;
import com.google.inject.Key;
import com.google.inject.Provider;
import com.google.inject.spi.BindingScopingVisitor;
import com.google.inject.spi.ElementVisitor;
import com.google.inject.spi.InstanceBinding;

public abstract class BindingImpl implements Binding {

    private final InjectorImpl injector;
    private final Key key;
    private final Object source;
    private final Scoping scoping;
    private final InternalFactory internalFactory;
    private volatile Provider provider;

    public BindingImpl(InjectorImpl injector, Key key, Object source,
                       InternalFactory internalFactory, Scoping scoping) {
        this.injector = injector;
        this.key = key;
        this.source = source;
        this.internalFactory = internalFactory;
        this.scoping = scoping;
    }

    protected BindingImpl(Object source, Key key, Scoping scoping) {
        this.internalFactory = null;
        this.injector = null;
        this.source = source;
        this.key = key;
        this.scoping = scoping;
    }

    @Override
    public Key getKey() {
        return key;
    }

    @Override
    public Object getSource() {
        return source;
    }

    @Override
    public Provider getProvider() {
        if (provider == null) {
            if (injector == null) {
                throw new UnsupportedOperationException("getProvider() not supported for module bindings");
            }

            provider = injector.getProvider(key);
        }
        return provider;
    }

    public InternalFactory getInternalFactory() {
        return internalFactory;
    }

    public Scoping getScoping() {
        return scoping;
    }

    /**
     * Is this a constant binding? This returns true for constant bindings as
     * well as toInstance() bindings.
     */
    public boolean isConstant() {
        return this instanceof InstanceBinding;
    }

    @Override
    public  V acceptVisitor(ElementVisitor visitor) {
        return visitor.visit(this);
    }

    @Override
    public  V acceptScopingVisitor(BindingScopingVisitor visitor) {
        return scoping.acceptVisitor(visitor);
    }

    protected BindingImpl withScoping(Scoping scoping) {
        throw new AssertionError();
    }

    protected BindingImpl withKey(Key key) {
        throw new AssertionError();
    }

    @Override
    public String toString() {
        return MoreObjects.toStringHelper(Binding.class)
                .add("key", key)
                .add("scope", scoping)
                .add("source", source)
                .toString();
    }

    public InjectorImpl getInjector() {
        return injector;
    }
}