unifying receiver

The service of one of the four components was pulled over the previous days, and today it is time to start talking about its brother Broadcastreceiver. Write here I am quite tangled, because the broadcast receiver is indeed relatively simple, but you do not think that simple is not connotation, perhaps we slowly explore another piece of heaven and earth.The usual practice is to introduce the basics, and later we'll talk about the order of reception of

1.1. Introduction to Broadcasting Android radio differs from the broadcast concept in life, which refers to the notification after an event is generated in the system. Android broadcasts are a one-way notification of whether the recipient is receiving processing or how to handle the broadcast. Android uses Braodcastreceiver to listen to broadcasts from the system, and different braodcastreceiver distinguish the type of listening broadcast by setting different fliter. Some broadcasts require

The main content of this section:I. Data acceptance architecture and design patternsSecond, the acceptance of the data source interpretationSpark streaming continuously receives data, with receiver's spark application in mind.Receiver and driver in different processes, receiver to receive data after the continuous reporting to deriver.Because driver is responsible for scheduling, receiver received data if n

message will receive an ACK.4. After the file data is sent, the sender sends the end of the file Z, receiver pays after receiving confirmation.5. When no files need to be sent, transmit end message B is sent, the ACK is received, and the connection is closed, and the physical connection remainsEach message is numbered and 0~63.XMODEMSimple and general, transmission information Unit is "packet =128b", transmission speed is slow, suitable for the poor

strict timing of the columns. In addition, CONTIKIMAC uses optimized fast sleep and optimized lock-in transmission.The mechanism in Contikimac is inspired by the already existing periodic moratorium protocol. Many protocols use the idea of periodic awakening, such as B-mac,x-mac,box-mac. The most optimized phase-lock technology was first proposed by Wisemac and has now been used in many other protocols. Multiple copies of the packet have been used by the TinyOS Box-mac protocol.The remainder of

The following is a description of three protocol for error control.1. Stop waiting for automatic Duplicate request protocol (stop-and-wait ARQ)The following figure is the process of stopping waiting for an automatic repeat request:In the figure, SN points to the number of frames that will be sent, and RN points to the number of frames expecting the next receipt. Where the number of frames can be recycled, determined by the bit length of the number field, if the Number field is 2 bits, the number

device is the GPS signal receiver. Its main function is to capture the satellites to be tested selected according to a certain satellite cutoff angle and track the operation of these satellites. After the receiver captures the tracked satellite signal, it can measure the pseudo distance and distance change rate between the receiving antenna and the satellite, and call out satellite orbit parameters and oth

Android Broadcast Mechanism Analysis1.1. Broadcast OverviewAndroid broadcast is different from broadcast in life. It refers to notifications generated after events in the system. Android broadcast is a one-way notification that does not care whether the receiver receives or processes the broadcast.Android uses BraodcastReceiver to listen to the broadcast sent by the system. Different BraodcastReceiver sets different fliter to distinguish the broadcast

Android Broadcast Mechanism Analysis and android Broadcast Mechanism1.1. Broadcast OverviewAndroid broadcast is different from broadcast in life. It refers to notifications generated after events in the system. Android broadcast is a one-way notification that does not care whether the receiver receives or processes the broadcast.Android uses BraodcastReceiver to listen to the broadcast sent by the system. Different BraodcastReceiver sets different fli

, that is, the plaintext (original data) cannot be exported Based on the ciphertext (encrypted data ). What we should note below is that data can be decrypted and restored after encryption. For objects to be encrypted, some are called messages, some are called data, and some are called information. To avoid confusion, I will refer to themMessage. So what is encryption? Encryption creates a secure communication mode by encoding messages so that only you and the expected

Design Mode-command modeOverview In software development, we often need to send requests (call one or some methods) to some objects, but we do not know who the request receiver is, we do not know which operation is requested. At this time, we especially hope to design software in a loosely coupled way so that the coupling between request senders and request recipients can be eliminated, this makes the call relationship between objects more flexible an

cases: cross-application domain, the actual proxy uses a formatter to serialize the message and put it into a remote channel. In cross-context environments, the actual proxy does not need to know the formatter, channel, and context interceptor, it only needs to intercept the call before passing the message forward, and then it passes the message to a message receiver (the object implementing imessagesink). Each r