Spring Boot 入门 404 错误

Question

我第一次尝试使用spring框架。 不幸的是，当我调用我的网络服务的 URL 时，我收到了 404 错误。 war 文件的 Tomcat 部署正在运行（日志中没有错误）。 当我在 Eclipse 中执行 Example.java 时，一切正常。

错误在哪里？

查看我的文件/日志：

Example.java

import org.springframework.boot.*;
import org.springframework.boot.autoconfigure.*;
import org.springframework.stereotype.*;
import org.springframework.web.bind.annotation.*;

@Controller
@EnableAutoConfiguration
public class Example {

    @RequestMapping("/")
    @ResponseBody
    String home() {
        return "Hello World!";
    }

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

构建.gradle

buildscript {
    repositories {
        jcenter()
        maven { url 'http://repo.spring.io/snapshot' }
        maven { url 'http://repo.spring.io/milestone' }
    }
    dependencies {
        classpath 'org.springframework.boot:spring-boot-gradle-plugin:2.0.0.BUILD-SNAPSHOT'
    }
}

task wrapper(type: Wrapper) {
    gradleVersion = '3.5'
}

apply plugin: 'java'
apply plugin: 'war'
apply plugin: 'org.springframework.boot'
apply plugin: 'io.spring.dependency-management'

jar {
    baseName = 'myproject'
    version =  '0.0.1-SNAPSHOT'
}

repositories {
    jcenter()
    maven { url "http://repo.spring.io/snapshot" }
    maven { url "http://repo.spring.io/milestone" }
}

dependencies {
    //compile 'org.slf4j:slf4j-api:1.7.21'

    compile("org.springframework.boot:spring-boot-starter-web")
    testCompile("org.springframework.boot:spring-boot-starter-test")

    //testCompile 'junit:junit:4.12'
}

在eclipse中启动应用程序时记录

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::  (v2.0.0.BUILD-SNAPSHOT)

2017-06-01 16:22:17.745  INFO 14940 --- [           main] Example                                  : Starting Example on Laptop-Timo with PID 14940 (started by Timo in C:\Users\Timo\Documents\SE\Semester 4\LabSW\Webservice\TimeShoppingService)
2017-06-01 16:22:17.745  INFO 14940 --- [           main] Example                                  : No active profile set, falling back to default profiles: default
2017-06-01 16:22:17.815  INFO 14940 --- [           main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@6a01e23: startup date [Thu Jun 01 16:22:17 CEST 2017]; root of context hierarchy
2017-06-01 16:22:20.098  INFO 14940 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2017-06-01 16:22:20.116  INFO 14940 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2017-06-01 16:22:20.116  INFO 14940 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.15
2017-06-01 16:22:20.264  INFO 14940 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2017-06-01 16:22:20.264  INFO 14940 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2449 ms
2017-06-01 16:22:20.626  INFO 14940 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2017-06-01 16:22:20.638  INFO 14940 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2017-06-01 16:22:20.639  INFO 14940 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2017-06-01 16:22:20.639  INFO 14940 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2017-06-01 16:22:20.640  INFO 14940 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2017-06-01 16:22:21.343  INFO 14940 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@6a01e23: startup date [Thu Jun 01 16:22:17 CEST 2017]; root of context hierarchy
2017-06-01 16:22:21.442  INFO 14940 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/]}" onto java.lang.String Example.home()
2017-06-01 16:22:21.456  INFO 14940 --- [           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.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2017-06-01 16:22:21.457  INFO 14940 --- [           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.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2017-06-01 16:22:21.548  INFO 14940 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-06-01 16:22:21.549  INFO 14940 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-06-01 16:22:21.683  INFO 14940 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-06-01 16:22:21.940  INFO 14940 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2017-06-01 16:22:22.018  INFO 14940 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http)
2017-06-01 16:22:22.024  INFO 14940 --- [           main] Example                                  : Started Example in 4.81 seconds (JVM running for 5.487)
2017-06-01 16:22:32.727  INFO 14940 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
2017-06-01 16:22:32.727  INFO 14940 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
2017-06-01 16:22:32.755  INFO 14940 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 28 ms

Answer 1

使用@RestController而不是@Controller并给出类似的请求

本地主机：8080/

Answer 2

为了将 spring-boot 应用程序部署到外部 servlet 容器，您需要扩展SpringBootServletInitializer 。

main 方法仅在应用程序独立运行时执行。
建议独立运行 spring-boot 应用程序，而不是通过外部 servlet 容器，但可以同时支持这两种方法。

有关更多信息，请参阅弹簧文档。

Answer 3

默认情况下，Spring 引导应用程序的上下文路径是“/”。 因此，在您的情况下，访问主页资源的 url 将是http://localhost:8080/

对于自定义上下文路径，将 application.properties 文件添加到 src\main\resources。 在该属性文件中，添加 2 个属性：

server.contextPath=/Service server.port=12378

例如，您可以参考此链接。

Answer 4

可能是网址错误。 试试下面的网址。

http://localhost:8080/Service/

Answer 5

您尚未使用任何特定字符串映射您的控制器或方法。

    @Controller
    @EnableAutoConfiguration
    public class Example {

        @RequestMapping("/")
        @ResponseBody
        String home() {
            return "Hello World!";
        }
...

您已经使用了映射home()方法的@RequestMapping("/") ，因此您需要使用localhost:8080/ url 而不是localhost:8080/service如果您想在 url 中使用该service ，只需将映射更改为@RequestMapping("/service") 。

Answer 6

最简单的方法就是分别替换类上方的注释。 并使用@RestController ，然后将@RequestMapping("/")移动到类上方，其余控制器下方。 转到邮递员并使用localhost:8080/调用它，仅此而已