java - Spring : There was an unexpected error (type=Not Found, 状态=404 的问题

Question

我正在阅读这本关于 Spring 的 Restful Web 服务的书。我决定放弃他们正在做的事情并使用 java 配置文件。出于某种原因，在切换到 Java 配置后，服务将正确运行(在控制台窗口中)，但是当我实际转到 localhost 上的端点时，我得到了这个:

White label Error Page

This application has no explicit mapping for /error, so you are seeing this as a fallback.

Sat Apr 23 20:48:25 PDT 2016 There was an unexpected error (type=Not Found, status=404). No message available

这是来自 GET 请求的响应:

{
    "timestamp": 1461470029110,
    "status": 404,
    "error": "Not Found",
    "message": "No message available",
    "path": "/greeting"
}

这个故事的下一章从我进入 Spring 网站上的入门页面开始 http://spring.io/guides/gs/rest-service/我决定开始一个小项目来重新创建他们的基本教程。我将在下面发布我编写的代码供您查看。问题是，我遇到了完全相同的问题。服务运行，但我无法到达端点。我不确定发生了什么，我看到其他人有类似的问题，但答案并没有适用/帮助我。我确信很明显我做错了，任何帮助将不胜感激。最后一条信息，如果有关系的话，我正在使用 IntelliJ IDEA 15 CE 作为我的 IDE。

被击中的端点:

http://localhost:8080/greeting

我的 Controller

@RestController
public class GreetingController {
    private static final String template = "Hello, %s!";
    private final AtomicLong counter = new AtomicLong();

    @RequestMapping("/greeting")
    public Greeting greeting(@RequestParam(value = "name", defaultValue = "World")String name) {
        return new Greeting(counter.incrementAndGet(), String.format(template, name));
    }
}

我的资源表示类

public class Greeting {
    private final long id;
    private final String content;

    public Greeting(long id, String content) {
        this.id = id;
        this.content = content;
    }

    public long getId() {
        return id;
    }

    public String getContent() {
        return content;
    }
}

我的主要

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

我的 POM 文件

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>com.organization_name.webservices</groupId>
<artifactId>helloworld</artifactId>
<version>1.0-SNAPSHOT</version>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.3.3.RELEASE</version>
</parent>

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

<properties>
    <java.version>1.8</java.version>
</properties>


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

<repositories>
    <repository>
        <id>spring-releases</id>
        <url>https://repo.spring.io/libs-release</url>
    </repository>
</repositories>
<pluginRepositories>
    <pluginRepository>
        <id>spring-releases</id>
        <url>https://repo.spring.io/libs-release</url>
    </pluginRepository>
</pluginRepositories>

命令行运行

mvn spring-boot:run   

来自控制台的完整日志

 .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.3.3.RELEASE)

2016-04-23 20:47:53.153  INFO 7898 --- [           main] c.t.webservices.application.Application  : Starting Application on Macintosh.local with PID 7898 (/Users/<my_user>/Downloads/B04788_Code/HelloWorld/target/classes started by <my_user> in /Users/<my_user>/Downloads/B04788_Code/HelloWorld)
2016-04-23 20:47:53.156  INFO 7898 --- [           main] c.t.webservices.application.Application  : No active profile set, falling back to default profiles: default
2016-04-23 20:47:53.242  INFO 7898 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@68ceda24: startup date [Sat Apr 23 20:47:53 PDT 2016]; root of context hierarchy
2016-04-23 20:47:54.084  INFO 7898 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Overriding bean definition for bean 'beanNameViewResolver' with a different definition: replacing [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration; factoryMethodName=beanNameViewResolver; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/web/ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration.class]] with [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter; factoryMethodName=beanNameViewResolver; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter.class]]
2016-04-23 20:47:54.811  INFO 7898 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2016-04-23 20:47:54.840  INFO 7898 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2016-04-23 20:47:54.841  INFO 7898 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.0.32
2016-04-23 20:47:54.960  INFO 7898 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2016-04-23 20:47:54.960  INFO 7898 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1736 ms
2016-04-23 20:47:55.214  INFO 7898 --- [ost-startStop-1] o.s.b.c.e.ServletRegistrationBean        : Mapping servlet: 'dispatcherServlet' to [/]
2016-04-23 20:47:55.218  INFO 7898 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean  : Mapping filter: 'characterEncodingFilter' to: [/*]
2016-04-23 20:47:55.219  INFO 7898 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean  : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2016-04-23 20:47:55.219  INFO 7898 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean  : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2016-04-23 20:47:55.219  INFO 7898 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean  : Mapping filter: 'requestContextFilter' to: [/*]
2016-04-23 20:47:55.545  INFO 7898 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@68ceda24: startup date [Sat Apr 23 20:47:53 PDT 2016]; root of context hierarchy
2016-04-23 20:47:55.605  INFO 7898 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2016-04-23 20:47:55.606  INFO 7898 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2016-04-23 20:47:55.628  INFO 7898 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2016-04-23 20:47:55.628  INFO 7898 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2016-04-23 20:47:55.657  INFO 7898 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2016-04-23 20:47:55.776  INFO 7898 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2016-04-23 20:47:55.848  INFO 7898 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2016-04-23 20:47:55.853  INFO 7898 --- [           main] c.t.webservices.application.Application  : Started Application in 3.531 seconds (JVM running for 4.702)
2016-04-23 20:48:19.521  INFO 7898 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
2016-04-23 20:48:19.521  INFO 7898 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
2016-04-23 20:48:19.533  INFO 7898 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 12 ms

GET 请求后更新控制台

2016-04-23 20:48:19.521  INFO 7898 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
2016-04-23 20:48:19.533  INFO 7898 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 12 ms

停止后的控制台

2016-04-23 20:53:24.494  INFO 7898 --- [       Thread-2] ationConfigEmbeddedWebApplicationContext : Closing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@68ceda24: startup date [Sat Apr 23 20:47:53 PDT 2016]; root of context hierarchy
2016-04-23 20:53:24.495  INFO 7898 --- [       Thread-2] o.s.j.e.a.AnnotationMBeanExporter        : Unregistering JMX-exposed beans on shutdown

Process finished with exit code 130

再次感谢您提供的任何帮助。我会及时通知大家更新!

Answer 1

我相信您的问题与包裹有关。您的应用程序在 com.organization_name.webservices.application 中定义。我猜你的其他类在不同的包中，它不是 com.organization_name.webservices.application 的子包。 Spring 会自动加载同一个包或子包中的 Controller ，例如:

com.organization_name.webservices.application
com.organization_name.webservices.application.controllers

但不是这样的包:

com.organization_name.webservices.controllers

您可以通过移动 Controller (或应用程序)或将 ComponentScan 添加到您的应用程序来解决此问题:

@SpringBootApplication
@ComponentScan(basePackageClasses=GreetingController.class)
public class Application {

您应该会在日志中看到这一点:

 Mapped "{[/greeting]}" onto public com.organization_name.webservices.xxx.Greeting com.organization_name.webservices.xxx.GreetingController.greeting(java.lang.String)