构建超媒体驱动的RESTful Web服务

╰半夏微凉° 2022-01-27 00:11 225阅读 0赞

## 文章来源：[https://spring.io/guides/gs/rest-hateoas/][https_spring.io_guides_gs_rest-hateoas] ##

### 一、创建maven工程sprint-boot-hypermedia-driven，pom.xml文件依赖如下： ###

<parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.4.RELEASE</version>
        </parent>
        
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-hateoas</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>com.jayway.jsonpath</groupId>
                <artifactId>json-path</artifactId>
                <scope>test</scope>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>

### 二、创建实体类Greeting.java ###

package com.szcatic.entity;
    
    import org.springframework.hateoas.ResourceSupport;
    
    import com.fasterxml.jackson.annotation.JsonCreator;
    import com.fasterxml.jackson.annotation.JsonProperty;
    
    public class Greeting extends ResourceSupport {
    
        private final String content;
        
        /**
             * 注解@JsonCreator 表示Jackson如何创建这个POJO实例
             * 注解@JsonProperty 清楚地标记了Jackson应该把什么属性放到构造参数里面
         * @param content
         */
        @JsonCreator
        public Greeting(@JsonProperty("content") String content) {
            this.content = content;
        }
    
        public String getContent() {
            return content;
        }
    }

### 三、创建控制类GreetingController.java ###

package com.szcatic.controller;
    
    import static org.springframework.hateoas.mvc.ControllerLinkBuilder.*;
    
    import org.springframework.http.HttpEntity;
    import org.springframework.http.HttpStatus;
    import org.springframework.http.ResponseEntity;
    import org.springframework.web.bind.annotation.RestController;
    
    import com.szcatic.entity.Greeting;
    
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    
    @RestController
    public class GreetingController {
    
        private static final String TEMPLATE = "Hello, %s!";
    
        @RequestMapping("/greeting")
        public HttpEntity<Greeting> greeting(
                @RequestParam(value = "name", required = false, defaultValue = "World") String name) {
    
            Greeting greeting = new Greeting(String.format(TEMPLATE, name));
            greeting.add(linkTo(methodOn(GreetingController.class).greeting(name)).withSelfRel());
    
            return new ResponseEntity<>(greeting, HttpStatus.OK);
        }
    }

### 四、创建引导类Application.java ###

package com.szcatic;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    public class Application {
    
        public static void main(String[] args) {
            SpringApplication.run(Application.class, args);
        }
    
    }

### 五、启动引导类 ###

.   ____          _            __ _ _
     /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
    ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
     \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
      '  |____| .__|_| |_|_| |_\__, | / / / /
     =========|_|==============|___/=/_/_/_/
     :: Spring Boot ::        (v2.1.4.RELEASE)
    
    2019-05-24 17:15:36.058  INFO 14200 --- [           main] com.szcatic.Application                  : Starting Application on zsx with PID 14200 (F:\workspace4.11\sprint-boot-hypermedia-driven\target\classes started by admin in F:\workspace4.11\sprint-boot-hypermedia-driven)
    2019-05-24 17:15:36.061  INFO 14200 --- [           main] com.szcatic.Application                  : No active profile set, falling back to default profiles: default
    2019-05-24 17:15:37.489  INFO 14200 --- [           main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.hateoas.config.HateoasConfiguration' of type [org.springframework.hateoas.config.HateoasConfiguration$$EnhancerBySpringCGLIB$$ebf1ec2c] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
    2019-05-24 17:15:37.997  INFO 14200 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
    2019-05-24 17:15:38.022  INFO 14200 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
    2019-05-24 17:15:38.027  INFO 14200 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.17]
    2019-05-24 17:15:38.034  INFO 14200 --- [           main] o.a.catalina.core.AprLifecycleListener   : An older version [1.2.16] of the APR based Apache Tomcat Native library is installed, while Tomcat recommends a minimum version of [1.2.21]
    2019-05-24 17:15:38.034  INFO 14200 --- [           main] o.a.catalina.core.AprLifecycleListener   : Loaded APR based Apache Tomcat Native library [1.2.16] using APR version [1.6.3].
    2019-05-24 17:15:38.034  INFO 14200 --- [           main] o.a.catalina.core.AprLifecycleListener   : APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].
    2019-05-24 17:15:38.034  INFO 14200 --- [           main] o.a.catalina.core.AprLifecycleListener   : APR/OpenSSL configuration: useAprConnector [false], useOpenSSL [true]
    2019-05-24 17:15:39.119  INFO 14200 --- [           main] o.a.catalina.core.AprLifecycleListener   : OpenSSL successfully initialized [OpenSSL 1.0.2m  2 Nov 2017]
    2019-05-24 17:15:39.355  INFO 14200 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
    2019-05-24 17:15:39.356  INFO 14200 --- [           main] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 3041 ms
    2019-05-24 17:15:39.692  INFO 14200 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
    2019-05-24 17:15:40.088  INFO 14200 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
    2019-05-24 17:15:40.091  INFO 14200 --- [           main] com.szcatic.Application                  : Started Application in 4.672 seconds (JVM running for 5.78)

### 六、打开postman ###

**6.1输入请求链接[http://localhost:8080/greeting][http_localhost_8080_greeting]，结果显示如下：**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzeDE4MjczMTE3MDAz_size_16_color_FFFFFF_t_70][]

**6.2输入请求链接[http://localhost:8080/greeting?name=User][http_localhost_8080_greeting_name_User]，结果显示如下：**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzeDE4MjczMTE3MDAz_size_16_color_FFFFFF_t_70 1][]

**从以上结果可以看出构建成功 **

### 七、项目目录结构如下： ###

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzeDE4MjczMTE3MDAz_size_16_color_FFFFFF_t_70 2][]

[https_spring.io_guides_gs_rest-hateoas]: https://spring.io/guides/gs/rest-hateoas/
[http_localhost_8080_greeting]: http://localhost:8080/greeting
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzeDE4MjczMTE3MDAz_size_16_color_FFFFFF_t_70]: /images/20220127/c113c5e2cca94c7a9c17bf0570f80ac6.png
[http_localhost_8080_greeting_name_User]: http://localhost:8080/greeting?name=User
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzeDE4MjczMTE3MDAz_size_16_color_FFFFFF_t_70 1]: /images/20220127/ddc079b89d6644648d8795c3223088a7.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzeDE4MjczMTE3MDAz_size_16_color_FFFFFF_t_70 2]: /images/20220127/8eaa9e65bbd449b0aa1c9725db8da850.png