src/main/java/com/alipay/remoting/ProcessorManager.java
public void registerDefaultProcessor(RemotingProcessor<?> processor) {
        if (this.defaultProcessor == null) {
            this.defaultProcessor = processor;
        } else {
            throw new IllegalStateException("The defaultProcessor has already been registered: "
                                            + this.defaultProcessor.getClass());
        }
    }
public void registerDefaultProcessor(RemotingProcessor<?> processor) {
        if (this.defaultProcessor == null) {
            this.defaultProcessor = processor;
        } else {
            throw new IllegalStateException("The defaultProcessor has already been registered: "
                                            + this.defaultProcessor.getClass());
        }
    }
Register the default processor to process command with no specific processor registered.

@param processor