[Bug]: Example value starting with a number is parsed incorrectly

[Sagr-gupta]

Description

When an example in an OpenAPI annotation (e.g., @Schema(example = "5 lacs per annum")) starts with a number, it appears that Swagger Core interprets the value as a numeric literal because the example begins with a digit. This results in the example being serialized as a number instead of a string.

For instance :

@Schema(example = "5 lacs per annum") private String salary;

In the generated OpenAPI schema, the example becomes:

"example": 5

instead of :

"example": "5 lacs per annum"

Where the issue occurs

The issue originates from the following code in io.swagger.v3.core.util.AnnotationsUtils#getSchemaFromAnnotation:

Because Json31.mapper().readTree(...) interprets any string starting with a digit as JSON numeric content,
the portion "lacs per annum" is ignored and only the number 5 is retained.

Affected Version

swagger-core-jakarta: 2.2.36

springdoc-openapi: 2.8.13

For reproducing the issue below I have attached a demo project. Kindly take reference.

openapi.zip