1.4 Distributed-Communication protocol TCP/IP

Server and browser communications rely on the HTTP protocol, today to analyze the specific content of the HTTP protocol and HTTPS encryption process. In addition to these protocols, in order to increase the scalability of server and browser interaction, there is also a restful style of request, easy to invoke the interface. An overview of the HTTP protocol

1. Client and server side

2. Resources

html/text, Word, AVI movie, Other resources

3. Media type

MIME type (tells the browser how to resolve this type). Text/html, Image/jpeg

4. Uri and URL

Uri:web the name of the server resource. Index.html

Url:http://www.gupaoedu.com:80/java/index.html[?query-string] #location

Analysis (Protocol):

Schema:http/https/ftp.

IP address or domain name of the Host:web server

Port: Server port, HTTP default access is 80

Path: Resource access Path

Query-string: Query Parameters

#location: Anchor Point (positioning)

5. Methods

Get/put/delete/post/head

Message

Request parameter, Response response parameter

The request message structure contains three parts: (Start line, header field, body)

Method/path/http/version-number

Header-name:value

Blank Line

Body Optional Request body

Response

Http/version-number Status Code message
Header-name:value

Body

Status code

Five types of status codes are defined in the http/1.1 version of the Protocol

1XX Tip Information

2XX success

3XX redirection

4XX Client Error

5XX Server-side error

Cache

The server can set whether to use the cache in the returned response

Features of the HTTP protocol

1. No status

Cookie+session (keep the server state)

2. Multiple requests

3. TCP protocol based

HTTPS

One more encryption on the HTTP protocol

SSL/TLS (encryption)

SSL3.0

ISOC released the upgrade version on the basis of SSL TLS1.2

How HTTPS works

Encrypt on HTTP basis

The first step is to use symmetric plus decryption

The second step, the key is public, all the clients can get (this may be intercepted)

The third step uses different keys for different clients

Problem: The negotiation process is not encrypted, so there will be truncated issues

Fourth step: Using asymmetric encryption

Asymmetric: The concept of public and private keys

Problem: How the client gets the public key

1. Server-side sends the public key to each client

2. Server side put the public key to the remote server, the client can request to

3. Let the browser save All public keys (unrealistic)

The fifth step of the public key is switched to the problem according to the above scheme, always exists.

Sixth step: Use a third-party organization to solve

Using a third party's private key to encrypt the public key we need to transfer through a third-party organization

Seventh part

What is included in the digital certificate:

Company Information, website information, digital certificate algorithm, public key

Connection process

Restful

REST Representational State transitions

Use Web standards to do some guidelines and constraints.

Basic concepts of restful

1. In rest, everything is considered a resource

2. Each resource is uniquely identified by a URI

3. Processing resource requests using a unified interface (Post/get/put/delete/head)

4. No status

Resources and URIs

1. [/] Indicates the hierarchical relationship of resources

2.? Filter resources

3. Use _ or-make the URI more readable

Unified interface

Get gets a resource. Power, etc.

POST to create a new resource

PUT replaces an existing resource (update operation), idempotent

Delete Deletes a resource

Patch/head

Resource presentation

MIME type ()

Accept:text/xml HTML file

Content-type tells the client the presentation of the resource

Resource Links

Hypermedia is the application state engine

State transitions

The server side should not save the client state.

App status-> Server side does not save app State

Access orders according to the interface to query

Visit Product Enquiry

The best design for restful

1. Domain Name

HTTP/api.gupaoedu.com

HTTP/Api/gupaoedu.com/api

2. Version

HTTP/api.gupaoedu.com/v1/user/1

Inside the header maintenance version

3. Path

http/api.gupaoedu.com/v1/users_list//Get user list

http//Api.gupaoedu.com/v1/goods-list //Product List

http/api.gupaoedu.com/v1/users/ {ID}

4. Filtering information

https://api.github.com/user/repos?page=2&per_page=100

https://developer.github.com/v3/#rate-limiting

5. Status Code

Business Status Code

HTTP status Code

1.4 Distributed-Communication protocol TCP/IP