春季启动 REST API 404 错误
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【中文标题】春季启动 REST API 404 错误【英文标题】:Spring boot REST API 404 error 【发布时间】:2018-10-05 00:11:48 【问题描述】:我正在尝试使用 REST API 创建一个基本的 Spring Boot 应用程序 (JDK 1.8)。 以下是我的应用代码
package org.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
@SpringBootApplication
@ComponentScan("org.demo")
@EnableAutoConfiguration
public class DemoApplication
public static void main(String[] args)
SpringApplication.run(DemoApplication.class, args);
我添加了一个简单的控制器如下
package org.demo.controllers;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
@RestController(value = "/hello")
public class HelloController
@GetMapping
@ResponseBody
public String hello()
return "Hello";
我的项目的POM文件如下
<?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>org.demo</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>2.0.1.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>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
当我运行这个应用程序时,它会成功启动。但是,当我尝试访问 URL localhost:8080 或 loclahost:8080/hello 时,我收到 404 错误消息
以下是启动日志 :: Spring Boot :: (v2.0.1.RELEASE)
2018-04-24 21:51:38.888 INFO 12068 --- [ main] org.demo.DemoApplication : Starting DemoApplication on DESKTOP-G2QR23G with PID 12068 (I:\demo\spring-boot\demo\target\classes started by chirayu in I:\demo\spring-boot\demo)
2018-04-24 21:51:38.892 INFO 12068 --- [ main] org.demo.DemoApplication : No active profile set, falling back to default profiles: default
2018-04-24 21:51:38.970 INFO 12068 --- [ main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@5745ca0e: startup date [Tue Apr 24 21:51:38 IST 2018]; root of context hierarchy
2018-04-24 21:51:39.617 INFO 12068 --- [ main] f.a.AutowiredAnnotationBeanPostProcessor : JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
2018-04-24 21:51:39.999 INFO 12068 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2018-04-24 21:51:40.030 INFO 12068 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2018-04-24 21:51:40.030 INFO 12068 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.29
2018-04-24 21:51:40.043 INFO 12068 --- [ost-startStop-1] o.a.catalina.core.AprLifecycleListener : The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [I:\Program Files\Java\jdk1.8.0_66\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\ProgramData\Oracle\Java\javapath;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;I:\Program Files\Java\jdk1.8.0_66\bin;I:\Program Files\nodejs\;C:\Program Files (x86)\GtkSharp\2.12\bin;C:\Program Files (x86)\Skype\Phone\;I:\MinGW\bin;C:\Program Files (x86)\mysql\MySQL Fabric 1.5 ^& MySQL Utilities 1.5\;C:\Program Files (x86)\MySQL\MySQL Fabric 1.5 ^& MySQL Utilities 1.5\Doctrine extensions for php\;I:\Program Files (x86)\maven\apache-maven-3.3.9\bin\;I:\Program Files (x86)\Heroku\bin;C:\Program Files (x86)\git\cmd;I:\Program Files\Git\cmd;I:\Program Files\PostgreSQL\9.6\bin;I:\RailsInstaller\Git\cmd;I:\RailsInstaller\Ruby2.2.0\bin;I:\Program Files (x86)\Python\Scripts\;I:\Program Files (x86)\Python\;C:\Users\chirayu\AppData\Roaming\npm;C:\Users\chirayu\AppData\Local\Microsoft\WindowsApps;I:\Program Files (x86)\Microsoft VS Code\bin;;.]
2018-04-24 21:51:40.164 INFO 12068 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2018-04-24 21:51:40.164 INFO 12068 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1198 ms
2018-04-24 21:51:40.215 INFO 12068 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-04-24 21:51:40.598 INFO 12068 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2018-04-24 21:51:40.633 INFO 12068 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2018-04-24 21:51:40.638 INFO 12068 --- [ main] org.demo.DemoApplication : Started DemoApplication in 2.2 seconds (JVM running for 2.797)
我不确定我可能会错过什么。请帮忙。
【问题讨论】:
尝试将@RestController(value = "/hello")
更改为@RestController @RequestMapping("/hello")
去掉@ComponentScan("org.demo")
和@EnableAutoConfiguration
注解,因为@SpringBootApplication // same as @Configuration @EnableAutoConfiguration @ComponentScan
。
如果你想扫描一些特定的包你可以使用@EntityScan(basePackages = "org.demo")
而不是@ComponentScan("org.demo")
我不确定问题出在哪里,但是当我将我的应用程序基础包 (org.demo) 重构为其他名称 (org.demo.app) 时,同一个控制器开始工作。现在,当我将基本包重构为原始(org.demo)名称时,它仍然可以工作
【参考方案1】:
我得到了解决方案。这是由于包裹的可见性。主类无法找到控制器类所在的包。所以在同一个包下添加了所有类。您还可以将应用程序类提高一级。从以下链接获得帮助:
Spring Boot: Cannot access REST Controller on localhost (404)
【讨论】:
我的主类和控制器包已经在同一级别了。至于将所有类放在同一个包下,这可能有效,但我更感兴趣的是为什么我的配置不起作用。【参考方案2】:测试如下...对我来说,从@RestController 符号中删除路径然后添加路径@GetMapping 符号如下@GetMapping("/hello") test http://localhost:8080/hello you应该得到正确的响应才能得到这个请求的响应 http://localhost:8080/hello/hello 需要添加以下内容:
@RestController
@RequestMapping(value = "/hello")
【讨论】:
【参考方案3】:改为:
@RestController
@RequestMapping(value = "hello-controller")
public class HelloController
@GetMapping(value="hello")
@ResponseBody
public String hello()
return "Hello";
所以你可以使用你的 api:localhost:8080/hello-controller/hello
@RequestMapping
下面@RestController
中的值是定义你的班级地址。
@GetMapping
中的值用于您的 API 地址。
希望这个解释对你有所帮助。
【讨论】:
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