SpringBoot的RequestMapping不工作

Question

我正在学习Spring Boot来构建应用程序。我试图用不同包中的控制器作为应用程序来构建我的第一个Spring Boot应用程序。Tomcat实例出现，但请求没有到达为URI注册的RestController。

以下是控制器类：

package com.spring.controllers;

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

@RestController
public class HelloController {

    @RequestMapping(value = "/abc")
    public String getHi() {
        System.out.println("End Point hit");
        return "Hi";
    }
}

以下是应用程序类：

package com.spring.boot;

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

@SpringBootApplication(scanBasePackages = {"com.spring.controllers"})
public class SpringBootMain {

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

Pom.xml

<?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>RandomProjects</groupId>
<artifactId>SpringBoot</artifactId>
<version>1.0-SNAPSHOT</version>

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

<build>
    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>2.3.2</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>1.6.0</version>
            <configuration>
                <mainClass>com.spring.boot.SpringBootMain</mainClass>
            </configuration>
        </plugin>
    </plugins>
</build>

<dependencies>

    <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-parent -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.6.RELEASE</version>
        <type>pom</type>
    </dependency>



    <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <version>1.5.6.RELEASE</version>
    </dependency>


</dependencies>

tomcat启动时的日志：

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.6.RELEASE)

2017-12-25 16:41:16.236  INFO 50314 --- [BootMain.main()] com.spring.boot.SpringBootMain           : Starting SpringBootMain on f45c89be9049.ant.amazon.com with PID 50314 (/Users/sumt/Desktop/Work/RandomWork/RandomProjects/target/classes started by sumt in /Users/sumt/Desktop/Work/RandomWork/RandomProjects)
2017-12-25 16:41:16.244  INFO 50314 --- [BootMain.main()] com.spring.boot.SpringBootMain           : No active profile set, falling back to default profiles: default
2017-12-25 16:41:16.408  INFO 50314 --- [BootMain.main()] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@7bbcce75: startup date [Mon Dec 25 16:41:16 IST 2017]; root of context hierarchy
2017-12-25 16:41:18.279  INFO 50314 --- [BootMain.main()] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2017-12-25 16:41:18.295  INFO 50314 --- [BootMain.main()] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2017-12-25 16:41:18.297  INFO 50314 --- [BootMain.main()] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.16
2017-12-25 16:41:18.402  INFO 50314 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2017-12-25 16:41:18.402  INFO 50314 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2056 ms
2017-12-25 16:41:18.560  INFO 50314 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2017-12-25 16:41:18.564  INFO 50314 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2017-12-25 16:41:18.565  INFO 50314 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2017-12-25 16:41:18.565  INFO 50314 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2017-12-25 16:41:18.566  INFO 50314 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2017-12-25 16:41:18.920  INFO 50314 --- [BootMain.main()] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@7bbcce75: startup date [Mon Dec 25 16:41:16 IST 2017]; root of context hierarchy
2017-12-25 16:41:19.005  INFO 50314 --- [BootMain.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)
2017-12-25 16:41:19.007  INFO 50314 --- [BootMain.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)
2017-12-25 16:41:19.041  INFO 50314 --- [BootMain.main()] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-12-25 16:41:19.041  INFO 50314 --- [BootMain.main()] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-12-25 16:41:19.084  INFO 50314 --- [BootMain.main()] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-12-25 16:41:19.323  INFO 50314 --- [BootMain.main()] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2017-12-25 16:41:19.407  INFO 50314 --- [BootMain.main()] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2017-12-25 16:41:19.413  INFO 50314 --- [BootMain.main()] com.spring.boot.SpringBootMain           : Started SpringBootMain in 3.889 seconds (JVM running for 6.196)

我添加了基本包扫描，甚至尝试了@ComponentScan注释，但当我点击URL（http://localhost:8080/abc）时结果是一样的：

出现意外错误（类型=未找到，状态=404）。没有可用消息

还有其他人面临同样的问题吗？请提出你是如何解决这个问题的。

Answer 1

作为一个建议，尝试调用默认执行器endpoint，例如http://localhost:8080/error。它们提出了Spring Boot，并将显示您的服务的实际状态。

Answer 2

正如评论中提到的，尝试添加基本包。

@SpringBootApplication(scanBasePackages = {"com.spring"})

或

@SpringBootApplication
@ComponentScan("com.spring")

但是你为什么不使用这个Spring初始化器呢https://start.spring.io/从头开始创建spring boot项目。您还可以添加任何需要的依赖项。

这是我试图从您的示例中复制的迷你控制器：

Spring应用程序

package com.example.demo.app;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;

@SpringBootApplication
@ComponentScan("com.example.demo.controller")
public class DemoApplication {

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

控制器

package com.example.demo.controller;

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

@RestController
public class HelloController {

    @RequestMapping(value = "/abc")
    public String getHi() {
        System.out.println("End Point hit");
        return "Hi";
    }
}

pom。xml

<?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.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

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

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

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


</project>

它工作得很好！

Answer 3

您的控制器应该在SpringBootApplication的子包中。e、 如果您的SpringbootApplication主方法在com下。文本那么你的控制器类应该在com下。文本演示。控制器。

或者在Spring boot Application主类上添加@ComponentScan（"com.text.demo.controller"）。