HTTP状态404-创建springBoot应用程序时未找到

Question

这是一个启动应用程序。它运行完美，但没有得到输出（它显示我的HTTP状态404错误在浏览器）

波姆。xml

<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.exaample.demo</groupId>
  <artifactId>SpringBootMaven</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>Maven spring boot project</name>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.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>
</project>

启动类Main方法

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class WebMainMethod {

    public static void main(String[] args) {
        SpringApplication.run(WebMainMethod.class, args);

    }

}

控制器在主类后加载

**Rest Controller**


package com.example.demo.controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {

    @RequestMapping("/hello")
    public String sayHi() {
        return "Hi";
    }
}

网址：http://localhost:8080/hello输出

Answer 1

您的端口似乎有问题8080。

请更改端口并尝试重新启动应用程序。

示例：将以下内容添加到应用程序中。属性文件

server.port = 8090

然后试着打http://localhost:8090/hello

Answer 2

也许你的模板不存在。请指定映射有返回值的模板的文件名。看看这个例子

@Controller
public class HelloWorldController {
    @RequestMapping("/hello")
    public String hello(Model model, @RequestParam(value="name", required=false, defaultValue="World") String name) {

        String message="You just create Spring Boot Example successfully";
        model.addAttribute("name", name);
        model.addAttribute("message", message);

        return "hello";
    }
}

这是从Spring Boot Maven示例Hello World中找到的

Answer 3

无法重现问题。

这不是一个答案，但我从问题中复制了3个文件，并毫无问题地构建和运行了代码。不过，我的控制台日志有点不同，包括在下面，这就是为什么我将此作为一个答案发布。

试着做一个干净的构建。也许这会解决问题。

控制台日志

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.9.RELEASE)

2017-12-02 02:06:19.763  INFO 13268 --- [           main] com.example.demo.WebMainMethod           : Starting WebMainMethod on XXXX with PID 13268 (C:\Users\XXXX\SpringBootMaven\target\classes started by Andreas in C:\Users\XXXX\SpringBootMaven)
2017-12-02 02:06:19.765  INFO 13268 --- [           main] com.example.demo.WebMainMethod           : No active profile set, falling back to default profiles: default
2017-12-02 02:06:19.794  INFO 13268 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@4f51b3e0: startup date [Sat Dec 02 02:06:19 EST 2017]; root of context hierarchy
2017-12-02 02:06:20.631  INFO 13268 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2017-12-02 02:06:20.641  INFO 13268 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2017-12-02 02:06:20.642  INFO 13268 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.23
2017-12-02 02:06:20.751  INFO 13268 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2017-12-02 02:06:20.751  INFO 13268 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 959 ms
2017-12-02 02:06:20.824  INFO 13268 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2017-12-02 02:06:20.826  INFO 13268 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2017-12-02 02:06:20.827  INFO 13268 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2017-12-02 02:06:20.827  INFO 13268 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2017-12-02 02:06:20.827  INFO 13268 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2017-12-02 02:06:21.025  INFO 13268 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@4f51b3e0: startup date [Sat Dec 02 02:06:19 EST 2017]; root of context hierarchy
2017-12-02 02:06:21.071  INFO 13268 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/hello]}" onto public java.lang.String com.example.demo.controller.HelloController.sayHi()
2017-12-02 02:06:21.074  INFO 13268 --- [           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)
2017-12-02 02:06:21.074  INFO 13268 --- [           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)
2017-12-02 02:06:21.095  INFO 13268 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-12-02 02:06:21.095  INFO 13268 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-12-02 02:06:21.119  INFO 13268 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-12-02 02:06:21.195  INFO 13268 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2017-12-02 02:06:21.271  INFO 13268 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2017-12-02 02:06:21.273  INFO 13268 --- [           main] com.example.demo.WebMainMethod           : Started WebMainMethod in 1.908 seconds (JVM running for 2.231)
2017-12-02 02:06:38.426  INFO 13268 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
2017-12-02 02:06:38.426  INFO 13268 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
2017-12-02 02:06:38.435  INFO 13268 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 9 ms