swagger-api/swagger-parser
As an API project, swagger-api/swagger-parser has picked up 870 stars on GitHub (Java). Swagger Spec to Java POJOs
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Swagger Parser 
NOTE: If you're looking for swagger-parser 1.X and OpenAPI 2.0, please refer to v1 branch
NOTE: Since version 2.1.0 Swagger Parser supports OpenAPI 3.1; see this page for details
Table of contents
- Overview
- Table of Contents
- Usage
- Adding to your project
- Prerequisites
- Authentication
- Options
- Resolve
- ResolveFully
- Flatten
- ResolveCombinators
- Extensions
- OpenAPI 3.1 Support
- License
Overview
This is the Swagger Parser project, which parses OpenAPI definitions in JSON or YAML format into swagger-core representation as Java POJO, returning any validation warnings/errors.
It also provides a simple framework to add additional converters from different formats into the Swagger objects, making the entire toolchain available.
Usage
Using the Swagger Parser is simple. Once included in your project, you can read a OpenAPI Specification from any location:
import io.swagger.parser.OpenAPIParser;
import io.swagger.v3.parser.OpenAPIV3Parser;
import io.swagger.v3.parser.core.models.SwaggerParseResult;
import io.swagger.v3.oas.models.OpenAPI;
// ... your code
// parse a swagger description from the petstore and get the result
SwaggerParseResult result = new OpenAPIParser().readLocation("https://petstore3.swagger.io/api/v3/openapi.json", null, null);
// or from a file
// SwaggerParseResult result = new OpenAPIParser().readLocation("./path/to/openapi.yaml", null, null);
// the parsed POJO
OpenAPI openAPI = result.getOpenAPI();
if (result.getMessages() != null) result.getMessages().forEach(System.err::println); // validation errors and warnings
if (openAPI != null) {
...
}
or from a string:
import io.swagger.parser.OpenAPIParser;
import io.swagger.v3.parser.OpenAPIV3Parser;
import io.swagger.v3.parser.core.models.SwaggerParseResult;
import io.swagger.v3.oas.models.OpenAPI;
// ... your code
// parse a swagger description from the petstore and get the result
SwaggerParseResult result = new OpenAPIParser().readContents("https://petstore3.swagger.io/api/v3/openapi.json", null, null);
// or from a file
// SwaggerParseResult result = new OpenAPIParser().readContents("./path/to/openapi.yaml", null, null);
// the parsed POJO
OpenAPI openAPI = result.getOpenAPI();
if (result.getMessages() != null) result.getMessages().forEach(System.err::println); // validation errors and warnings
if (openAPI != null) {
...
}
If you are providing a Swagger/OpenAPI 2.0 document to the parser , e.g.:
SwaggerParseResult result = new OpenAPIParser().readContents("./path/to/swagger.yaml", null, null);
the Swagger/OpenAPI 2.0 document will be first converted into a comparable OpenAPI 3.0 one.
You can also directly use OpenAPIV3Parser which only handles OpenAPI 3.0 documents, and provides a convenience method to get directly the parsed `OpenAPI object:
import io.swagger.v3.parser.OpenAPIV3Parser;
import io.swagger.v3.oas.models.OpenAPI;
// ... your code
// read a swagger description from the petstore
OpenAPI openAPI = new OpenAPIV3Parser().read("https://petstore3.swagger.io/api/v3/openapi.json");
Adding to your project
You can include this library from Sonatype OSS for SNAPSHOTS, or Maven central for releases. In your dependencies:
<dependency>
<groupId>io.swagger.parser.v3</groupId>
<artifactId>swagger-parser</artifactId>
<version>2.1.48</version>
</dependency>
Prerequisites
You need the following installed and available in your $PATH:
- Java 11
- Apache maven 3.x
After cloning the project, you can build it from source with this command:
mvn package
Authentication
If your OpenAPI definition is protected, you can pass headers in the request:
import io.swagger.v3.parser.core.models.AuthorizationValue;
// ... your code
// build a authorization value
AuthorizationValue mySpecialHeader = new AuthorizationValue()
.keyName("x-special-access") // the name of the authorization to pass
.value("i-am-special") // the value of the authorization
.type("header"); // the location, as either `header` or `query`
// or in a single constructor
AuthorizationValue apiKey = new AuthorizationValue("api_key", "special-key", "header");
OpenAPI openAPI = new OpenAPIV3Parser().readWithInfo(
"https://petstore3.swagger.io/api/v3/openapi.json",
Arrays.asList(mySpecialHeader, apiKey)
);
Dealing with self-signed SSL certificates
If you're dealing with self-signed SSL certificates, or those signed by GoDaddy, you'll need to disable SSL Trust Manager. That's done by setting a system environment variable as such:
export TRUST_ALL=true
And then the Swagger Parser will ignore invalid certificates. Of course this is generally a bad idea, but if you're working inside a firewall or really know what you're doing, well, there's your rope.
Dealing with Let's Encrypt
Depending on the version of Java that you use, certificates signed by the Let's Encrypt certificate authority may not work by default. If you are using any version of Java prior to 1.8u101, you most likely must install an additional CA in your JVM. Also note that 1.8u101 may not be sufficient on its own. Some users have reported that certain operating systems are not accepting Let's Encrypt signed certificates.
Your options include:
- Accepting all certificates per above
- Installing the certificate manually in your JVM using the keystore using the
keytoolcommand - Configuring the JVM on startup to load your certificate
But... this is all standard SSL configuration stuff and is well documented across the web.
Options
Parser uses options as a way to customize the behavior while parsing:
1. resolve:
ParseOptions parseOptions = new ParseOptions();
parseOptions.setResolve(true);
final OpenAPI openAPI = new OpenAPIV3Parser().read("a.yaml", null, parseOptions);
- When remote or relative references are found in the parsed document, parser will attempt to:
- resolve the reference in the remote or relative location
- parse the resolved reference
- add the resolved "component" (e.g. parameter, schema, response, etc.) to the resolved
OpenAPIPOJO components section - replace the remote/relative reference with a local reference, e.g. :
#/components/schemas/NameOfRemoteSchema.
This applies to schemas, parameters, responses, pretty much everything containing a ref.
For OpenAPI 3.0 documents, the OpenAPIResolver and ExternalRefProcessor path adds numeric suffixes such as Name_1 for name collisions.
This behavior prevents data loss. It can change generated component keys, local $ref values, and component counts for documents with name collisions.
OpenAPI 3.1 uses a separate dereferencer. This numeric-suffix change does not modify OpenAPI 3.1 resolution.
2. resolveFully:
ParseOptions parseOptions = new ParseOptions();
parseOptions.setResolve(true); // implicit
parseOptions.setResolveFully(true);
final OpenAPI openAPI = new OpenAPIV3Parser().read("a.yaml", null, parseOptions);
- In some scenarios, after references are resolved (with
resolve, see above), you might need to have all local references removed replacing the reference with the content of the referenced element. This is for example used in Swagger Inflector. Be aware that the result could be more heavy/long due to duplication
Original document:
a.yaml
openapi: 3.0.1
paths:
"/newPerson":
post:
summary: Create new person
description: Create new person
responses:
'200':
description: ok
content:
"*/*":
schema:
"$ref": "./ref-without-component/b.yaml#/components/schemas/CustomerType"
b.yaml
openapi: 3.0.1
components:
schemas:
CustomerType:
type: string
example: Example value
Serialized result after parsing with option resolveFully(true)
a.yaml
openapi: 3.0.1
servers:
- url: /
paths:
/newPerson:
post:
summary: Create new person
description: Create new person
responses:
200:
description: ok
content:
'*/*':
schema:
type: string
example: Example value
components:
schemas:
CustomerType:
type: string
example: Example value
3. flatten:
ParseOptions parseOptions = new ParseOptions();
parseOptions.setFlatten(true);
final OpenAPI openAPI = new OpenAPIV3Parser().read("a.yaml", null, parseOptions);
This is kind of the opposite of resolveFully, limited to defined schemas.
In some scenarios, you might need to have all schemas defined inline (e.g. a response schema) moved to the components/schemas section and replaced with a reference to the newly added schema within components/schemas. This is for example used in Swagger Codegen.
Original document:
flatten.yaml
openapi: 3.0.0
info:
version: 1.0.0
title: Swagger Petstore
license:
name: MIT
paths:
/pets:
get:
summary: List all pets
operationId: listPets
responses:
'200':
description: An paged array of pets
headers:
x-next:
description: A link to the next page of responses
schema:
type: string
content:
application/json:
schema:
type: object
properties:
id:
type: integer
format: int64
name:
type: string
tag:
type: string
Serialized result after parsing with option flatten(true)
openapi: 3.0.0
info:
title: Swagger Petstore
license:
name: MIT
version: 1.0.0
servers:
- url: /
paths:
/pets:
get:
tags:
- pets
summary: List all pets
responses:
200:
description: An paged array of pets
headers:
x-next:
description: A link to the next page of responses
style: simple
explode: false
schema:
type: string
content:
application/json:
schema:
$ref: '#/components/schemas/inline_response_200'
components:
schemas:
inline_response_200:
type: object
properties:
id:
type: integer
format: int64
name:
type: string
tag:
type: string
4. resolveCombinators:
ParseOptions parseOptions = new ParseOptions();
parseOptions.setResolve(true); // implicit
parseOptions.setResolveFully(true);
parseOptions.setResolveCombinators(false); // default is true
final OpenAPI openAPI = new OpenAPIV3Parser().read("a.yaml", null, parseOptions);
This option (only available with resolveFully = true) allows to customize behaviour related to allOf/anyOf/oneOf (composed schemas) processing. With option set to true (default), composed schemas are transformed into "non composed" ones, by having all properties merged into a single resulting schema (see example below).
If option is set to false, the resulting schema will instead maintain its "composed" nature, keeping properties within e.g. the allOf members.
Please see examples below:
Unresolved yaml
openapi: 3.0.1
servers:
- url: http://petstore.swagger.io/api
info:
description: 'This is a sample server Petstore'
version: 1.0.0
title: testing source file
termsOfService: http://swagger.io/terms/
paths:
"/withInvalidComposedModel":
post:
operationId: withInvalidComposedModel
requestBody:
content:
"application/json":
schema:
"$ref": "#/components/schemas/ExtendedAddress"
required: false
responses:
'200':
description: success!
components:
schemas:
ExtendedAddress:
type: object
allOf:
- $ref: '#/components/schemas/Address'
- type: object
required:
- gps
properties:
gps:
type: string
Address:
required:
- street
type: object
properties:
street:
type: string
example: 12345 El Monte Road
city:
type: string
example: Los Altos Hills
state:
type: string
example: CA
zip:
type: string
example: '94022'
resolvedCombinator = true (default) - Test case
@Test
public void resolveAllOfWithoutAggregatingParameters(@Injectable final List<AuthorizationValue> auths) {
ParseOptions options = new ParseOptions();
options.setResolveFully(true);
options.setResolveCombinators(true);
// Testing components/schemas
OpenAPI openAPI = new OpenAPIV3Parser().readLocation("src/test/resources/composed.yaml",auths,options).getOpenAPI();
ComposedSchema allOf = (ComposedSchema) openAPI.getComponents().getSchemas().get("ExtendedAddress");
assertEquals(allOf.getAllOf().size(), 2);
assertTrue(allOf.getAllOf().get(0).get$ref() != null);
assertTrue(allOf.getAllOf().get(1).getProperties().containsKey("gps"));
// Testing path item
ObjectSchema schema = (ObjectSchema) openAPI.getPaths().get("/withInvalidComposedModel").getPost().getRequestBody().getContent().get("application/json").getSchema();
assertEquals(schema.getProperties().size(), 5);
assertTrue(schema.getProperties().containsKey("street"));
assertTrue(schema.getProperties().containsKey("gps"));
}
resolvedCombinator = true (default) - Resolved Yaml
openapi: 3.0.1
info:
title: testing source file
description: This is a sample server Petstore
termsOfService: http://swagger.io/terms/
version: 1.0.0
servers:
- url: http://petstore.swagger.io/api
paths:
/withInvalidComposedModel:
post:
operationId: withInvalidComposedModel
requestBody:
content:
application/json:
schema:
required:
- gps
- street
type: object
properties:
street:
type: string
example: 12345 El Monte Road
city:
type: string
example: Los Altos Hills
state:
type: string
example: CA
zip:
type: string
example: "94022"
gps:
type: string
required: false
responses:
200:
description: success!
components:
schemas:
ExtendedAddress:
type: object
allOf:
- $ref: '#/components/schemas/Address'
- required:
- gps
type: object
properties:
gps:
type: string
Address:
required:
- street
type: object
properties:
street:
type: string
example: 12345 El Monte Road
city:
type: string
example: Los Altos Hills
state:
type: string
example: CA
zip:
type: string
example: "94022"
resolvedCombinator = false - Test case
@Test
public void resolveAllOfWithoutAggregatingParameters(@Injectable final List<AuthorizationValue> auths) {
ParseOptions options = new ParseOptions();
options.setResolveFully(true);
options.setResolveCombinators(false);
// Testing components/schemas
OpenAPI openAPI = new OpenAPIV3Parser().readLocation("src/test/resources/composed.yaml",auths,options).getOpenAPI();
ComposedSchema allOf = (ComposedSchema) openAPI.getComponents().getSchemas().get("ExtendedAddress");
assertEquals(allOf.getAllOf().size(), 2);
assertTrue(allOf.getAllOf().get(0).getProperties().containsKey("street"));
assertTrue(allOf.getAllOf().get(1).getProperties().containsKey("gps"));
// Testing path item
ComposedSchema schema = (ComposedSchema) openAPI.getPaths().get("/withInvalidComposedModel").getPost().getRequestBody().getContent().get("application/json").getSchema();
// In fact the schema resolved previously is the same of /withInvalidComposedModel
assertEquals(schema, allOf);
assertEquals(schema.getAllOf().size(), 2);
assertTrue(schema.getAllOf().get(0).getProperties().containsKey("street"));
assertTrue(schema.getAllOf().get(1).getProperties().containsKey("gps"));
}
resolvedCombinator = false - Resolved Yaml
openapi: 3.0.1
info:
title: testing source file
description: This is a sample server Petstore
termsOfService: http://swagger.io/terms/
version: 1.0.0
servers:
- url: http://petstore.swagger.io/api
paths:
/withInvalidComposedModel:
post:
operationId: withInvalidComposedModel
requestBody:
content:
application/json:
schema:
type: object
allOf:
- required:
- street
type: object
properties:
street:
type: string
example: 12345 El Monte Road
city:
type: string
example: Los Altos Hills
state:
type: string
example: CA
zip:
type: string
example: "94022"
- required:
- gps
type: object
properties:
gps:
type: string
required: false
responses:
200:
description: success!
components:
schemas:
ExtendedAddress:
type: object
allOf:
- required:
- street
type: object
properties:
street:
type: string
example: 12345 El Monte Road
city:
type: string
example: Los Altos Hills
state:
type: string
example: CA
zip:
type: string
example: "94022"
- required:
- gps
type: object
properties:
gps:
type: string
Address:
required:
- street
type: object
properties:
street:
type: string
example: 12345 El Monte Road
city:
type: string
example: Los Altos Hills
state:
type: string
example: CA
zip:
type: string
example: "94022"
5. explicitObjectSchema:
ParseOptions parseOptions = new ParseOptions();
parseOptions.setResolve(true); // implicit
parseOptions.setResolveFully(true);
parseOptions.setResolveCombinators(false);
parseOptions.setExplicitObjectSchema(false); // default is true
final OpenAPI openAPI = new OpenAPIV3Parser().read("a.yaml", null, parseOptions);
This option allows you to customize the processing of schema properties when the type is not specified. By default it is set to true.
true: when the type is not defined for property, ‘object’ is set.false: the property remains undefined when no type is specified It's only applied whenresolveFullyis set totrue.
Extensions
This project has a core artifact--swagger-parser, which uses Java Service Provider Interface (SPI) so additional extensions can be added.
To build your own extension, you simply need to create a src/main/resources/META-INF/services/io.swagger.v3.parser.core.extensions.SwaggerParserExtension file with the full classname of your implementation. Your class must also implement the io.swagger.v3.parser.core.extensions.SwaggerParserExtension interface. Then, including your library with the swagger-parser module will cause it to be triggered automatically.
OpenAPI 3.1 support
Since version 2.1.0 Swagger Parser supports OpenAPI 3.1; see this page for details
Security contact
Please disclose any security-related issues or vulnerabilities by emailing [email protected], instead of using the public issue tracker.
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Quick answers
How active is development on swagger-api/swagger-parser?
The most recent commit recorded on swagger-api/swagger-parser was 1 month ago, based on the GitHub push timestamp. The repository has 566 forks — one of the better signals of community interest.
How does swagger-api/swagger-parser compare to other API projects?
swagger-api/swagger-parser is tracked by TopGit in the API category, with 870 GitHub stars and written in Java. Browse the API topic page on TopGit to compare it against similar projects by stars and activity.
How many stars does swagger-api/swagger-parser have?
swagger-api/swagger-parser has 870 GitHub stars — refresh the page for the live number, or check github.com/swagger-api/swagger-parser. TopGit mirrors GitHub's count but does not claim minute-by-minute accuracy.
What is swagger-api/swagger-parser?
swagger-api/swagger-parser (swagger-api/swagger-parser) is a Java project on GitHub. From the project's own README: Swagger Spec to Java POJOs
What language is swagger-api/swagger-parser written in?
swagger-api/swagger-parser is written primarily in Java. GitHub's language field is based on the largest share of bytes in the default branch.
What topics is swagger-api/swagger-parser associated with?
GitHub's repository topics for swagger-api/swagger-parser: "hacktoberfest", "java", "open-source", "openapi", "openapi-specification", "openapi3", "rest", "rest-api", "swagger", "swagger-oss", "swagger-parser". TopGit's editorial category is API.
Why is swagger-api/swagger-parser categorized under API?
TopGit places swagger-api/swagger-parser in the API category based on its GitHub topics and description (tagged: "hacktoberfest", "java", "open-source"). Categories are assigned from real repository metadata, not editorial guesswork.
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