创建Springboot项目

第一步创建项目

第二步

第三步配置application.yml

server: port: 8080 

第四步引入包

pom.xml文件配置

<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <version>2.6.4</version> </dependency> </dependencies> 

第五步创建测试类

创建一个TestController

@Controller public class TestController { 
      @GetMapping("/test") @ResponseBody public String test(){ 
      return "Ok"; } } 

第六步浏览器访问地址

配置knife4j

官网

第一步 在pom.xml中添加knife4j的包

<dependency> <groupId>com.github.xiaoymin</groupId> <artifactId>knife4j-spring-boot-starter</artifactId> <version>3.0.3</version> </dependency> 

第二步 创建Swagger配置依赖

@Configuration @EnableSwagger2WebMvc public class Knife4jConfiguration { 
      @Bean(value = "defaultApi2") public Docket defaultApi2() { 
      Docket docket=new Docket(DocumentationType.SWAGGER_2) .apiInfo(new ApiInfoBuilder() .title("swagger-bootstrap-ui-demo RESTful APIs") .description("# swagger-bootstrap-ui-demo RESTful APIs") .termsOfServiceUrl("http://www.xx.com/") .version("1.0") .build()) //分组名称 .groupName("2.X版本") .select() //这里指定Controller扫描包路径 .apis(RequestHandlerSelectors.basePackage("com.mcc.controller")) .paths(PathSelectors.any()) .build(); return docket; } } 

注意：apis的扫描包路径需要改成自己的

第三步 启动项目发现报错如下

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled. 2022-03-01 18:16:49.020 ERROR 12556 --- [ main] o.s.boot.SpringApplication : Application run failed org.springframework.context.ApplicationContextException: Failed to start bean 'documentationPluginsBootstrapper'; nested exception is java.lang.NullPointerException at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:181) ~[spring-context-5.3.16.jar:5.3.16] at org.springframework.context.support.DefaultLifecycleProcessor.access$200(DefaultLifecycleProcessor.java:54) ~[spring-context-5.3.16.jar:5.3.16] at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:356) ~[spring-context-5.3.16.jar:5.3.16] at java.lang.Iterable.forEach(Iterable.java:75) ~[na:1.8.0_202] at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:155) ~[spring-context-5.3.16.jar:5.3.16] at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:123) ~[spring-context-5.3.16.jar:5.3.16] at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:935) ~[spring-context-5.3.16.jar:5.3.16] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:586) ~[spring-context-5.3.16.jar:5.3.16] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.4.jar:2.6.4] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) [spring-boot-2.6.4.jar:2.6.4] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) [spring-boot-2.6.4.jar:2.6.4] at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-2.6.4.jar:2.6.4] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) [spring-boot-2.6.4.jar:2.6.4] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) [spring-boot-2.6.4.jar:2.6.4] at com.mcc.TestKnif4jApplication.main(TestKnif4jApplication.java:10) [classes/:na] Caused by: java.lang.NullPointerException: null at springfox.documentation.spring.web.WebMvcPatternsRequestConditionWrapper.getPatterns(WebMvcPatternsRequestConditionWrapper.java:56) ~[springfox-spring-webmvc-3.0.0.jar:3.0.0] at springfox.documentation.RequestHandler.sortedPaths(RequestHandler.java:113) ~[springfox-core-3.0.0.jar:3.0.0] at springfox.documentation.spi.service.contexts.Orderings.lambda$byPatternsCondition$3(Orderings.java:89) ~[springfox-spi-3.0.0.jar:3.0.0] at java.util.Comparator.lambda$comparing$77a9974f$1(Comparator.java:469) ~[na:1.8.0_202] at java.util.TimSort.countRunAndMakeAscending(TimSort.java:355) ~[na:1.8.0_202] at java.util.TimSort.sort(TimSort.java:220) ~[na:1.8.0_202] at java.util.Arrays.sort(Arrays.java:1512) ~[na:1.8.0_202] at java.util.ArrayList.sort(ArrayList.java:1462) ~[na:1.8.0_202] at java.util.stream.SortedOps$RefSortingSink.end(SortedOps.java:387) ~[na:1.8.0_202] at java.util.stream.Sink$ChainedReference.end(Sink.java:258) ~[na:1.8.0_202] at java.util.stream.Sink$ChainedReference.end(Sink.java:258) ~[na:1.8.0_202] at java.util.stream.Sink$ChainedReference.end(Sink.java:258) ~[na:1.8.0_202] at java.util.stream.Sink$ChainedReference.end(Sink.java:258) ~[na:1.8.0_202] at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482) ~[na:1.8.0_202] at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) ~[na:1.8.0_202] at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708) ~[na:1.8.0_202] at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:1.8.0_202] at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499) ~[na:1.8.0_202] at springfox.documentation.spring.web.plugins.WebMvcRequestHandlerProvider.requestHandlers(WebMvcRequestHandlerProvider.java:81) ~[springfox-spring-webmvc-3.0.0.jar:3.0.0] at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) ~[na:1.8.0_202] at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382) ~[na:1.8.0_202] at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481) ~[na:1.8.0_202] at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) ~[na:1.8.0_202] at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708) ~[na:1.8.0_202] at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:1.8.0_202] at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499) ~[na:1.8.0_202] at springfox.documentation.spring.web.plugins.AbstractDocumentationPluginsBootstrapper.withDefaults(AbstractDocumentationPluginsBootstrapper.java:107) ~[springfox-spring-web-3.0.0.jar:3.0.0] at springfox.documentation.spring.web.plugins.AbstractDocumentationPluginsBootstrapper.buildContext(AbstractDocumentationPluginsBootstrapper.java:91) ~[springfox-spring-web-3.0.0.jar:3.0.0] at springfox.documentation.spring.web.plugins.AbstractDocumentationPluginsBootstrapper.bootstrapDocumentationPlugins(AbstractDocumentationPluginsBootstrapper.java:82) ~[springfox-spring-web-3.0.0.jar:3.0.0] at springfox.documentation.spring.web.plugins.DocumentationPluginsBootstrapper.start(DocumentationPluginsBootstrapper.java:100) ~[springfox-spring-web-3.0.0.jar:3.0.0] at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:178) ~[spring-context-5.3.16.jar:5.3.16] ... 14 common frames omitted Disconnected from the target VM, address: '127.0.0.1:49618', transport: 'socket' 

第四步 配置application.yml 如下

spring: mvc: pathmatch: matching-strategy: ant_path_matcher 

第五步 修改TestController如下

@Api(tags = "测试knife4j") @Controller public class TestController { 
      @ApiImplicitParam(name = "name",value = "姓名",required = true) @ApiOperation(value = "测试使用") @GetMapping("/test") @ResponseBody public String test(String name){ 
      return name; } } 

第六步 启动项目访问地址

第七步 接口内容如下图

第八步 测试接口如下图

knif4j使用yml配置版本

第一步 yml配置如下

springdoc: swagger-ui: path: /swagger-ui.html
    tags-sorter: alpha operations-sorter: alpha api-docs: path: /v3/api-docs group-configs: - group: 'default' paths-to-match: '/' packages-to-scan: com.mcc.springbootdemo knife4j: enable: true setting: language: zh_cn swagger-model-name: com.mcc.springbootdemo.entity documents: - name: 标题1 locations: classpath:markdown/* group: default - name: 标题2 locations: classpath:markdown1/* group: 用户模块 

第二步 注入依赖

<!-- knife4j --> <dependency> <groupId>com.github.xiaoymin</groupId> <artifactId>knife4j-openapi2-spring-boot-starter</artifactId> <version>4.0.0</version> </dependency> 

今天的文章 SpringBoot与knif4j学习分享到此就结束了，感谢您的阅读。