How does JMeter implement interface association?

Jmeter When used for interface test , The latter interface often needs to use the results returned by the previous interface , How to get the result value of the previous request , Applied to the latter interface , Take a login example to illustrate how to get .

1、 open jmeter, Create a new test plan , Create a new thread group in the test plan , Create a new login http request , As shown in the figure ：

2、 View the results returned by login ：

3、 The recharge interface can only be operated after logging in , You can use cookie The way , Verify that this user is logged in , Add... In the recharge interface cookie Manager ：

there sign It is returned by the last login interface sign value ,

4、 Create a new post processor under the login request , Extract the returned result value ：

 5、 View the operation results of the interface ：

summary ： That's all jmeter The association implementation of , If there are other interfaces that need the result of the previous request , You can also add a post processor to extract variables , Function in the last interface , Realize the dynamic change of parameters . 

Examples of regular expressions ：

1、 Extract a single string ：
If you want to match Web The following parts of the page ：name = "file" value = "readme.txt"> And extract readme.txt. A suitable regular expression ：name = "file" value = "(.+?)">.
　　　　　　()： Encapsulates the matching string to be returned .
　　　　　　.： Match any single string .
　　　　　　+： Once or more .
　　　　　　?： Don't be greedy , Stop after first match found .

2、 Extract multiple strings ：
　　　　 If you want to match Web The following parts of the page ：name = "file.name" value = "readme.txt"> And extract file.name and readme.txt. A suitable regular expression ：name = "(.+?)" value = "(.+?)". This will create 2 A set of , for $1$ and $2$

　　 such as ：

　　　　 Quote name ：MYREF
　　　　 Templates ：$1$$2$

　　　 The values of the following variables will be set ：
　　　　MYREF: 　　　　file.namereadme.txt
　　　　MYREF_g0:　　 name = "file.name"value = "readme.txt"
　　　　MYREF_g1:　　file.name
　　　　MYREF_g2:　　readme.txt

　　 Where you need to quote, you can use ：${MYREF}, ${MYREF_g1 To use .

When there is a dependency between requests , For example, the input parameter of one request is the data returned by another request , In this case, we need to use association processing ,Jmeter Can pass “ Post Processors ” Medium “ Regular expression extractor ” To deal with the correlation .

Simple association

For example, when visiting Baidu home page, there is one in the response data title

<title> use Baidu Search , You will know </title> I just want to quote this in other requests title

Add a regular expression extractor and set it as follows ：

Add an association request to verify the Association ：

After execution, we see that the association is successful

A more complex connection , Like taking multiple values in the regular expression result

For example, the response data of a request is as follows ：

Let's try to extract 0.0,84956.0,1019,3 These four data , Add a regular expression extractor and make the following settings

Quote name ： Reference name and reference method , Don't explain , Similar to variable parameterization .

Regular expressions ： Replace all parts to be quoted with parentheses , For the specific expressions in parentheses, you can refer to the knowledge related to regular expressions separately .

Templates ： Represents the style referenced from the regular expression result , In fact, the result is a group of , Instead of a .$0$ Represents all of this set of results ,$1$ The number one that represents this set of results 1 individual , And so on ;

$1$$2$ Represents the... Th in a set of results of the regular expression 1 And the first 2 individual , The two ended up next to each other without a gap between them ;

$3$,$4$ Represents the... Th in a set of results of the regular expression 3 And the first 4 individual , There is a comma between the two results .

Match the Numbers ：0 Represents random... In the regular expression result group ,1 Represent all .

The default value ： Display the information passed when the reference is not correct , Write one smoothly ERROR.

After setting up the regular expression extractor as above , We can add an associated authentication request , as follows ：

in fact ,myref_g0,myref_g1...myref_g4 Is the result group of regular expressions , and myref Is the result extracted by template control , Here, in order to more clearly observe the result group of regular expression, so many parameters are added to the verification request , The actual use is to use a myref Just match with the template .

myref_g0={"rent":0.0,"price":84956.0,"totalprice":1019,"roomType":3}

myref_g1=0.0

myref_g2=84956.0

myref_g3=1019

myref_g4=3

1. Templates $0$

2. Templates $1$$2$

3. Templates $3$,$4$

 

In addition, for matching numbers , At present, I only see 0 and 1, There may be other cases of taking other integers , That must be a more complicated situation .

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