DescriptorCache.java 文件源码

public ImmutableDescriptor get(ImmutableDescriptor descriptor) {
    WeakReference<ImmutableDescriptor> wr = map.get(descriptor);
    ImmutableDescriptor got = (wr == null) ? null : wr.get();
    if (got != null)
        return got;
    map.put(descriptor, new WeakReference<ImmutableDescriptor>(descriptor));
    return descriptor;
}