JMeter interface automation - how to solve the content type conflict of request headers

One 、 Preface

Usually we use Jmeter When doing interface automation , Add... To the thread group HTTP Header Manager , Used to manage public request header information . Ordinary interface automation is no problem , But for some special operation processes , Such as ： First upload the file interface （ Header usage Content-Type: multipart/form-data）, Then the operation is transmitted json Format interface （ Header usage Content-Type: application/json）, The request header information of these two interfaces will conflict .

Next, we will solve this problem step by step according to the example .

Two 、 Original script

For example: 5 Interface , Together, it is an automated operation process .

1- Image upload

2- Get service data

3- Set the service picture

4- Set service status

5- Get service status

among ：

“1- Image upload ” The interface request header is Content-Type: multipart/form-data

“3- Set the service picture ”、“4- Set service status ” The interface request header is Content-Type: application/json

Add... Under thread group HTTP Header Manager , Add value as Content-Type: application/json

“1- Image upload ” The interface is set Content-Type: multipart/form-data

Each interface adds a response assertion .

The script structure ：

Execute the script ：

“1- Image upload ” The request header of the interface is Content-Type: application/json, instead of Content-Type: multipart/form-data

therefore “1- Image upload ” Interface , Do not use public HTTP Request header information in header manager .

3、 ... and 、 Original script optimization 1

Optimize the original script

Will be public HTTP Adjust the position of the header manager , Not as a public request header , Instead, specify adding... To the interface that needs the request header .

“1- Image upload ” The interface is of upload type , Has been set in the request Content-Type: multipart/form-data

“2- Get service data ”、“5- Get service status ” The interface does not need to add a request header .

“3- Set the service picture ”、“4- Set service status ” The interface needs to add a request header （Content-Type: application/json）, So add HTTP Header manager .

The script structure ：

Execute the script ：

All interfaces are successfully implemented .

“1- Image upload ” Interface request header information .

“3- Set the service picture ” Interface request header information .

shortcoming ： When there are many interfaces , If a large number of interfaces need to be specified HTTP Header Manager , Maintenance is a little troublesome 、 And the script looks a little bloated , It is inconvenient to modify uniformly .

Four 、 Original script optimization 2

Optimize the original script

take “1- Image upload ” The interface is extracted from the original thread group , Put it separately into the new thread group , That is, two thread groups .“1- Image upload ” The interface is in a thread group , Other interfaces are in a thread group .

In the thread group where other interfaces are located HTTP Header Manager , Request header value unchanged .

The script structure ：

Execute the script ：

Run two thread groups at the same time , All interfaces are successfully implemented .

shortcoming ： Although the automated script composed of two thread groups can run through the business process , But this method divides threads , It doesn't look like a whole . Especially when there are more and more thread group scripts , It's a little inconvenient to implement .

5、 ... and 、 The original script is finally optimized

Optimize the original script

because “1- Image upload ” The interface does not need the request header information in the public header , So add the BeanShell PreProcessor Preprocessor , Delete the information in the public request header .

Script code ：

import org.apache.jmeter.protocol.http.control.HeaderManager;
//  Get request header information 
HeaderManager headers = sampler.getHeaderManager();
//  Print all request header information 
log.info(" Before deleting " + headers.getHeaders().getStringValue());
//  Delete the information specified in the request header 
sampler.getHeaderManager().removeHeaderNamed("Content-Type");
//  Print all request header information 
log.info(" After deleting " + headers.getHeaders().getStringValue());

At this time, the specified information in the public request header is deleted , Later interfaces will use this information , So add it back on the subsequent interface , for example “3- Set the service picture ” Interfaces will use public headers , Add BeanShell PreProcessor Preprocessor , Add the request header information to the public request header .

Script code ：

import org.apache.jmeter.protocol.http.control.HeaderManager;
import org.apache.jmeter.protocol.http.control.Header;
//  Get request header information 
HeaderManager headers = sampler.getHeaderManager();
//  Print all request header information 
log.info(" Before adding " + headers.getHeaders().getStringValue());
// new One Header object 
myHeader = new Header("Content-Type", "application/json");
//  add to Header To the request header Manager 
headers.add(myHeader);
//  Print all request header information 
log.info(" After adding " + headers.getHeaders().getStringValue());

After the request header information is successfully added , If this information is needed for subsequent interfaces , Then there is no need to add （BeanShell PreProcessor Preprocessor ）, You can use it .

Public HTTP Header Manager , Request header value unchanged .

The script structure ：

Execute the script ：

All interfaces are successfully implemented .

“1- Image upload ” Interface request header information .

“3- Set the service picture ” Interface request header information .

View the log printed during execution , Print out the deletion and addition request header information .

Be careful ： Public HTTP Header manager disable or delete , Executing the script will report an error .

Even if the script adds request header information , But the specified request header cannot be found .