HTTP request data solution and request data Solution

HTTP request data solution and request data Solution

The server has static data. Each time a mobile client logs in, it requires an http request to obtain data. To reduce the pressure on the server, the android client needs to know whether the data is old or the latest data, old data is not requested, and new data is obtained.

Please kindly advise!

Solution: HTTP Status 500 -?

500 is a Server Error
400 is a Clinet Error
300 Route change
200 OK

The response code, although it is SIP, is also applicable to HTTP, but adds something

Response Code
The response code is included, and the HTTP/1.1 response code is extended. Not all HTTP/1.1 Response codes are properly applied, but only pointed out in the discount. Other HTTP/1.1 Response codes should not be used. In addition, SIP also defines a new response code series, 6xx.

1. Temporary response 1xx
A temporary response, that is, a message response, indicates that the other server is processing the request and has not yet decided on the final response. If it takes more than ms for the server to process the request to generate an end response, it should send a 1xx response.
Note that 1xx responses are not reliably transmitted. They will not cause the client to send an ACK response. A temporary (1xx) response can contain a message body and a session description.
1.1 100 Trying
This response indicates that the server of the next node has received the request and has not executed the specific action of the request (for example, when the database is being opened ). This response, like other temporary responses, has been planted with UAC to resend INVITE requests. The 100 (Trying) response is different from other temporary responses. Here, it will never be forwarded to the upstream stream by a stateful proxy.
1.2 180 Ringing
UA receives the INVITE request and tries to prompt the user. This response should generate a local response.
1.3 818 Call is Being Forwarded (Call Forwarded)
The server can use this response code to indicate that the call is being forwarded to another destination set.
1.4 182 Queued
When the caller is temporarily unable to receive the call, and the server decides to wait in queue for the call, rather than rejecting the call, the server should send this response. When the called party resumes receiving the call, it will return an appropriate final response. For this call status, there can be a phrase indicating the reason, such as: "5 callqueued; expected waiting time is 15minutes ". The server can provide several 182 (Queued) Responses to inform the caller of the queue (for example, the queue is in front of the queue ).
1.5 183 session progress
The 183 (Session Progress) response is used to indicate the Progress of the conversation. Reason-Phrase (a sentence that expresses the Reason), header domain, or message body can be used to display more information about the call progress.
2. Successful message 2xx
This response indicates that the request is successful.
2.1 200 OK
The request has been processed successfully. This information depends on the response of requests of different methods.
3 forwarding request 3XX
The 3xx series of responses are used to indicate the user's new location information or to forward additional service locations to meet the call requirements.
3.1 300 Multiple Choices
There are multiple choices for the requested address. Each choice has its own address. The user or (UA) can select an appropriate communication terminal and forward the request to this address.
A response can contain a Resource feature that is allowed in the Accept request header domain at each location, so that the user or UA can select the most appropriate address to forward the request. The message body that does not have this response defines the MIME type.
These addresses should also be listed in the Contact header field (section 20.10 ). Unlike HTTP, a SIP response can contain multiple Contact header domains or a Contact header domain with an address list. UA can use the Contact Header domain for automatic forwarding or ask the user to confirm the forwarding. However, this specification does not define the automatic forwarding standard.
If the called party can be found at multiple addresses and the server cannot or is unwilling to forward the request, this response can be used to send the request to the caller.
3.2 301 Moved Permently
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Database solutions: known Relational Models .................. Write down the steps to solve the problem, and add more points.

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