Spring Boot Java应用部署Heroku遇404，本地正常求排查

部署Spring Boot（Java）应用到Heroku，部署状态显示成功且应用已启动，但访问https://herokuprojectest.herokuapp.com/main/status返回HTTP Status 404 – Not Found，Heroku日志记录了该404请求；本地访问http://localhost:8080/main/status可正常获取{"status":"ok"}结果。

pom.xml配置 #

<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.3</version>
        <relativePath/> 
    </parent>
    <packaging>war</packaging>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>project</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>17</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-autoconfigure</artifactId>
            <version>2.7.1</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals><goal>copy</goal></goals>
                        <configuration>
                            <artifactItems>
                                <artifactItem>
                                    <groupId>com.heroku</groupId>
                                    <artifactId>webapp-runner</artifactId>
                                    <version>9.0.30.0</version>
                                    <destFileName>webapp-runner.jar</destFileName>
                                </artifactItem>
                            </artifactItems>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

        </plugins>
    </build>

</project>

Procfile内容 #

web:    java $JAVA_OPTS -jar target/dependency/webapp-runner.jar --port $PORT target/*.war 

Controller代码 #

@RestController
@CrossOrigin(origins = "*")
@RequestMapping("/main")
public class MainController {

   @GetMapping("/status")
   public ResponseEntity<Model> getStatus(Model model, WebRequest request) {
       model.addAttribute("status", "ok");
       return ResponseEntity.ok(model);
   }

}

错误排查与解决办法 #

1. WAR包部署缺少Servlet初始化配置
   打包成WAR包部署到外部容器时，Spring Boot启动类需要继承SpringBootServletInitializer，否则容器无法识别应用入口。修改启动类：

   @SpringBootApplication
   public class DemoApplication extends SpringBootServletInitializer {
       @Override
       protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
           return application.sources(DemoApplication.class);
       }
   
       public static void main(String[] args) {
           SpringApplication.run(DemoApplication.class, args);
       }
   }
   

2. webapp-runner与Spring Boot版本不兼容
   当前使用的webapp-runner:9.0.30.0对应Tomcat 9.0.30，而Spring Boot 2.7.3默认依赖Tomcat 9.0.65，版本差距过大可能引发兼容性问题。升级webapp-runner版本：

   <artifactItem>
       <groupId>com.heroku</groupId>
       <artifactId>webapp-runner</artifactId>
       <version>9.0.65.0</version>
       <destFileName>webapp-runner.jar</destFileName>
   </artifactItem>
   

3. 依赖版本冲突
   手动添加的spring-boot-autoconfigure:2.7.1与父依赖管理的2.7.3版本不一致，会导致配置加载异常。删除该手动依赖：

   <!-- 移除以下依赖 -->
   <dependency>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-autoconfigure</artifactId>
       <version>2.7.1</version>
   </dependency>
   

4. Procfile中WAR包路径匹配问题
   若Maven生成的WAR包带版本号（如demo-0.0.1-SNAPSHOT.war），target/*.war可能匹配异常，可明确指定包名：

   web: java $JAVA_OPTS -jar target/dependency/webapp-runner.jar --port $PORT target/demo-0.0.1-SNAPSHOT.war
   

内容的提问来源于stack exchange，提问作者Max