Interface test

1. What is an interface

Generally speaking, there are two kinds of interfaces ： The internal interface of the program and the external interface of the system

External interface of the system ： For example, you need to get resources or information from other websites or servers , No one else will share the database with you , He can only give you a way they've written to get the data , You can use the method he wrote by referring to the interface provided by him , In order to achieve the purpose of data sharing , For example, we use app、 These URLs are called through the interface during data processing .

Program internal interface ： Between methods , Interaction between modules , The interface thrown inside the program , such as bbs System , There are login modules 、 Post module and so on , If you want to post, you have to log in first , To post, you have to log in , Then the two modules have to interact , It will throw out an interface , For internal system call .

1.1 Common interface types

1、webService Interface ： It's going soap Agreement passed http transmission , Both request message and return message are xml Format , We use the tools to call when testing , test . The tools available are SoapUI、jmeter、loadrunner etc. ;

2、http api Interface ： It's going http agreement , Differentiate called methods by path , The request message is key-value Formal , The return message is usually json strand , Yes get and post Other methods , This is also the two most commonly used request methods . The tools available are postman、RESTClient、jmeter、loadrunner etc. ;

1.2 Components of the interface

The interface shall have at least the request address 、 Request method 、 Request parameters （ In and out ） form , Some interfaces have request headers header.

URL Include ：schema（ agreement ）、host（ domain name ）、path（ route ）、query string（ Parameters ）、anchor（ anchor ）;

2. How to measure the interface

The most commonly used interface types include get and post Two kinds of ;

GET Request and POST Differences in requests ：

1、GET Use URL or Cookie The ginseng . and POST Put the data in BODY in .
2、GET Of URL There will be a length limit , be POST The data can be very large .
3、POST Than GET Security , Because the data is not visible on the address bar .
4、 commonly get Request to get data ,post Requests are used to send data .

session and cookie The difference between ：

         1.cookie The data is stored on the client's browser ,session Data on the server ;

         2.cookie Not very safe , Others can analyze those stored locally cookie And carry on cookie cheating , Should be used in consideration of safety session;

         3.session It will be saved on the server for a certain time . When visits increase , We will compare the performance of your server to reduce the performance of your server , Should be used cookie.

         4. Single cookie The saved data cannot exceed 4K, Many browsers limit a site to save at most 20 individual cookie.

         5. Therefore, it is recommended to store important information such as login as session, If other information is retained , Can be placed in cookie;

Common return status codes ：

         1xx - message
         2xx - success
         3xx - Redirect
         4xx - Client error
         5xx - Server error

        (200.201.204.304.400.401.403.404.410.500.503)