AWS Lambda 与 Java Spring

Question

我正在尝试使用 Java Spring 实现 AWS Lambda 服务。我经历了一大堆教程，这些教程告诉了我一大堆方法，但我无法让它发挥作用。

我遇到的主要问题是 AWS Lambda 库要求类具有零参数构造函数，这使得使用 Spring IOC 容器变得困难。我发现a tutorial 有一个解决方法，并且能够在创建后将我的 Spring bean 注入到类中，但是这种方法似乎不适用于从定义的接口（例如 Spring Data Repositories）创建的匿名类的 bean 实例化，这是我的应用程序使用的东西。

我在 AWS lambda 库的 Spring 包装器上找到了 a tutorial，但这似乎也不起作用；我想我已经或多或少正确地从their sample code 复制了他们的代码，但是当我在 Lambda 上运行它时，我收到以下错误：

START RequestId: d9e62756-e72b-45f0-8df4-2164f3979dd7 Version: $LATEST
Failed to discover main class. An attempt was made to discover main class as 'MAIN_CLASS' environment variable, system property as well as entry in META-INF/MANIFEST.MF (in that order).: java.lang.IllegalStateException
java.lang.IllegalStateException: Failed to discover main class. An attempt was made to discover main class as 'MAIN_CLASS' environment variable, system property as well as entry in META-INF/MANIFEST.MF (in that order).
    at org.springframework.cloud.function.utils.FunctionClassUtils.getStartClass(FunctionClassUtils.java:83)
    at org.springframework.cloud.function.utils.FunctionClassUtils.getStartClass(FunctionClassUtils.java:60)
    at org.springframework.cloud.function.adapter.aws.FunctionInvoker.start(FunctionInvoker.java:104)
    at org.springframework.cloud.function.adapter.aws.FunctionInvoker.<init>(FunctionInvoker.java:70)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

这是我的代码：

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">
    <parent>
        <artifactId>spring-boot-starter-parent</artifactId>
        <groupId>org.springframework.boot</groupId>
        <version>2.2.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>JobsTest</artifactId>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-function-adapter-aws</artifactId>
            <version>3.0.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-lambda-java-events</artifactId>
            <version>2.0.2</version>
        </dependency>
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-lambda-java-core</artifactId>
            <version>1.1.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-deploy-plugin</artifactId>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <configuration>
                    <createDependencyReducedPom>false</createDependencyReducedPom>
                    <shadedArtifactAttached>true</shadedArtifactAttached>
                    <shadedClassifierName>aws</shadedClassifierName>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

JobTestApplication.java（我正在使用一个示例 PoC 应用程序来尝试让这个该死的东西正常工作，然后我将一一为其添加更多高级功能）：

package jobtest;

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

import java.util.function.Function;

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

    @Bean
    public Function<Object, String> uppercase() {
        return input -> "Hello World!";
    }
}

有人可以向我解释我做错了什么吗？我已经花了 2 天半的时间来解决这个问题，但我无法弄清楚。谢谢。

Answer 1

我遇到了同样的问题。根据此链接https://github.com/spring-cloud/spring-cloud-function/issues/439，Spring Cloud Function 版本 3.0.2 可能会解决您的问题。