SpingBoot映射不起作用。404状态

Question

我一步一步地在youtube上学习教程，但我没有得到结果。守则如下：

主要应用

@SpringBootApplication
public class Application {
    public static void main(String[] args) throws Exception {
        SpringApplication.run(Application.class, args);
    }
}

模型类

public class Greeting {

    private BigInteger id;
    private String text;

    public Greeting() {}

    public BigInteger getId() {
        return id;
    }

    public void setId(BigInteger id) {
        this.id = id;
    }

    public String getText() {
        return text;
    }

    public void setText(String text) {
        this.text = text;
    }
}

问候控制器

@RestController()
public class GreetingController {

    private static BigInteger nextId;
    private static Map<BigInteger, Greeting> greetingMap;

    private static Greeting save(Greeting greeting) {
        if (greetingMap == null) {

            greetingMap = new HashMap<BigInteger, Greeting>();
            nextId = BigInteger.ONE;
        }
        greeting.setId(nextId);
        nextId = nextId.add(BigInteger.ONE);
        greetingMap.put(greeting.getId(), greeting);
        return greeting;
    }

    static {
        Greeting g1 = new Greeting();
        g1.setText("Hello World");
        save(g1);
        Greeting g2 = new Greeting();
        g2.setText("Hola Mundo!");
        save(g2);
    }

    @RequestMapping(
            value = "/api/greetings",
            method = RequestMethod.GET,
            produces = MediaType.APPLICATION_JSON_VALUE)
    public ResponseEntity<Collection<Greeting>> getGreetings() {
        Collection<Greeting> greetings = greetingMap.values();

        return new ResponseEntity<Collection<Greeting>>(greetings, HttpStatus.OK);
    }
}

Pom.xml文件

<modelVersion>4.0.0</modelVersion>

<groupId>com.hakeem.webservice2</groupId>
<artifactId>WebService2</artifactId>
<version>0.0.1-SNAPSHOT</version>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.2.1.RELEASE</version>
</parent>

<dependencies>

    <dependency>

        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>

    </dependency>

</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>

</build>

每当我运行get请求时，我都会从邮递员那里得到以下响应：

{
    "timestamp": 1439128293727,
    "status": 404,
    "error": "Not Found",
    "message": "No message available",
    "path": "/api/greetings"
}

或来自铬的下列内容：

白色标签错误页 此应用程序没有/error的显式映射，因此您认为这是一种退步。 太阳08月08:43:41COT 2015有一个意想不到的错误(type=Not Found，status=404)。没有可用的消息

我一步一步地跟踪录像。视频上的导师似乎没有做任何额外的事情。每当我输入

本地主机:8080/api/问候

我只得到了前面提到的错误。

加法。这是控制台输出，我不知道它是否有用：

2015-08-09 10:49:09.918 INFO 7696 -主com.hakeem.webservice2.应用:在笔记本电脑上启动PID 7696 (C:\Users\HakeemAbdussamad\Documents\MarsWorkspace\WebService2\target\classes，由HakeemAbdussamad在C:\Users\HakeemAbdussamad\Documents\MarsWorkspace\WebService2) 2015中启动-08- 09 10:49:09.988 INFO 7696 -主ationConfigEmbeddedWebApplicationContext :刷新org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@7bb0e64a:启动日期太阳08月10:49:09 COT 2015；上下文层次结构(根) 2015-08-09 10:49:10.710 INFO 7696 -主factoryBeanName=org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration；：重写bean定义的bean 'beanNameViewResolver'：替换[根bean:类null；scope=；abstract=false；lazyInit=false；autowireMode=3；dependencyCheck=0；autowireCandidate=true；primary=false；primary=false factoryMethodName=beanNameViewResolver；initMethodName=null；destroyMethodName=(推断)；在类路径资源org/springframework/boot/autoconfigure/web/ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration.class]中定义为[Root : class null；scope=；abstract=false；lazyInit=false；lazyInit=false；autowireMode=3；lazyInit=false；lazyInit=false；scope=；scope=；abstract=false；lazyInit=false；lazyInit=false；autowireMode=3；scope=；scope=；abstract=false；lazyInit=false；lazyInit=false；autowireMode=3；scope=；abstract=false；lazyInit=false；lazyInit=false；autowireMode=3；scope=；abstract=false；lazyInit=false])；factoryBeanName=org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter；factoryMethodName=beanNameViewResolver；initMethodName=null；destroyMethodName=(推断)；在类路径资源org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter.class] 2015-08-09 10:49:11.547 INFO 7696 -主s.b.c.e.t.TomcatEmbeddedServletContainer :使用端口初始化的Tomcat : 8080 (http) 2015-08-09 10:49:11.797 INFO 7696 -主o.apache.catalina.core.StandardService :启动服务Tomcat 2015-08-09 10:49:11.801主org.apache.catalina.core.StandardEngine :启动Servlet引擎: Apache /8.0.15 2015-08-09 10:49:11.926 INFO 7696 - ost-startStop-1 o.c.Tomcat.localhost./:初始化Spring 2015-08-09 10:49:11.926 INFO 7696 - ost-startStop-1 o.s.web.context.ContextLoader：根WebApplicationContext:初始化完成于1942年ms 2015-08-09 10:49:12.743 INFO 7696 - ost-startStop-1 o.s.b.c.e.ServletRegistrationBean :映射servlet：'dispatcherServlet‘to / 2015-08-09 10:49:12.747 INFO 7696 -- ost-startStop-1 o.s.b.c.embedded.FilterRegistrationBean :映射筛选器：'characterEncodingFilter’to: /_ 2015-08-09 10:49:12.747 INFO 7696- ost-startStop-1 o.s.b.c.embedded.FilterRegistrationBean :映射筛选器：“hiddenHttpMethodFilter”到: /_ 2015-08-09 10:49:12.963 INFO 7696 -主s.w.s.m.m.a.RequestMappingHandlerAdapter :查找@ControllerAdvice: o.s.b.c.embedded.FilterRegistrationBean启动日期: Sun 08月10:49:09 COT 2015；上下文层次结构的根2015-08-09 10:49:13.035 INFO 7696 --主s.w.s.m.m.a.RequestMappingHandlerMapping : main "{/error，methods=[]，params=[]，headers=[]，consumes=[]，produces=[]，org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest) 2015-08-09 10:49:13.036 INFO 7696 --主要s.w.s.m.m.a.RequestMappingHandlerMapping : main s.w.s.m.m.a.RequestMappingHandlerMapping:main "{/error，methods=[]，params=[]，headers=[]，consumes=[]，produces=text/html，org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest) 2015-08-09 10:49:13.108 INFO 7696 -主o.s.w.s.handler.SimpleUrlHandlerMapping :映射的URL路径/**到类org.springframework.web.servlet.resource.ResourceHttpRequestHandler 2015-08-09 10:49:13.108 INFO 7696 -custom=[]}main org.springframework.web.servlet.resource.ResourceHttpRequestHandler路径/webjars/**映射到类org.springframework.web.servlet.resource.ResourceHttpRequestHandler 2015-08-09 10:49:13.191 INFO 7696-主o.s.j.e.a.AnnotationMBeanExporter :在启动时为JMX公开注册beans 08-09 10:49:13.329 INFO 7696 -主s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat启动端口: 8080 (http) 2015-08-09 10:49:13.331 INFO 7696 -主com.hakeem.webservice2应用程序: 3.733秒内启动应用程序(JVM运行4.32)

Answer 1

给出的代码在我看来是对的。查看完整的源代码可能会有所帮助。例如，如果GreetingController类不在同一个包中，或者不在Application类的子包中，则不会扫描它，因此将出现此错误。