Technical analysis and application instance of the Swagger UI framework in the Java class library

Swagger is an open source framework for constructing, designing and documentation RESTFUL Web services.Swagger UI is a sub -item of Swagger. It is a front -end framework for visually presenting the Restful API document.This article will analyze the technical principles of the Swagger UI framework and provide a Java -based application instance. 1. Technical analysis of Swagger UI 1. Based on OpenAPI specification: Swagger UI is based on OpenAPI specifications.OpenAPI specifies a standard JSON or YAML format to describe the structure and functions of the RESTFUL APIS.Swagger UI generates API documents by parsing the OpenAPI specification file. 2. API document generation: Swagger UI can automatically generate API documents based on the code, annotations and configuration files in the project.It can automatically extract API information through the code and annotations in the item, including URL, request method, parameters, response, etc.At the same time, the Swagger UI also supports the information of the API through the configuration file. 3. The front -end interface display: Swagger UI shows the API document in a visualized manner.It generates an interactable interface for each API, including API's URL, request method, parameter list, request examples, response results, etc.Users can test and debug the API through the Swagger UI interface. 4. Support online testing: Swagger UI also provides a built -in testing tool that allows users to test API directly on the interface.Users can enter the test data and send the request according to the defined API parameter, and then view the results and response information of the request. 5. Multi -language support: Swagger UI supports API document display with multiple programming languages, including Java, Python, Ruby, etc.Users can choose the corresponding Swagger UI plugin according to their own project language. Example: Use Swagger UI to build API documents Below is a Java instance that uses Swagger UI to build API documents: 1. First, add swagger dependencies to the pom.xml file of the project: <dependency> <groupId>io.springfox</groupId> <artifactId>springfox-swagger2</artifactId> <version>2.9.2</version> </dependency> <dependency> <groupId>io.springfox</groupId> <artifactId>springfox-swagger-ui</artifactId> <version>2.9.2</version> </dependency> 2. Add Swagger configuration to the startup class of Spring Boot application: @Configuration @EnableSwagger2 public class SwaggerConfig { @Bean public Docket api() { return new Docket(DocumentationType.SWAGGER_2) .select() .apis(RequestHandlerSelectors.basePackage("com.example.controller")) .paths(PathSelectors.any()) .build(); } } 3. Add Swagger annotation to the method of the Controller class: @RestController @RequestMapping("/api") @API (tags = "API interface") public class ApiController { @APIPERATION ("Get user information") @ApiResponses({ @APIRESPONSE (CODE = 200, Message = "Success"), @Apiresponse (CODE = 400, Message = "Parameter Error") }) @GetMapping("/user/{id}") public ResponseEntity<User> getUser(@PathVariable("id") Long id) { // ... } } 4. Start the application and visit the Swagger UI interface: http:// localhost: 8080/SWAGGER-UI.html Through the above steps, we can see the generated API documents on the Swagger UI interface, including interface URL, request method, parameter, and response information.Users can test and debug on the interface. Summarize: This article understands the technical principles of the SWAGGER UI framework, and provides a Java -based application example.Swagger UI provides a convenient way to generate and display the RESTFUL API document to help developers better design and test the API interface.Through Swagger UI, we can improve the visualization of API, simplify the writing and maintenance of API documents, and improve the efficiency of teamwork.