无法解决错误：应用程序无法使用类路径启动：答案

【问题标题】：Unable to resolve the error: Application failed to start with classpath:无法解决错误：应用程序无法使用类路径启动：
【发布时间】：2022-01-06 15:00:44
【问题描述】：

运行 java spring boot 应用程序时出现以下错误。首先，我转到主包中的 application.java 文件并作为 Java 应用程序运行。

```Error:
Application failed to start with classpath: ...
36:45.59 [main] ERROR org.springframework.boot.SpringApplication - Application run failed. 
com.amazonaws.SdkClientException : Unable to find region via the region provider chain. Must provide an explicit region in the builder or setup environment to supply a region.```

以下是 pom.xml 文件：

```<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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <!-- we are extending from this project POM which means we get everything 
        that this pom has (inheritance) -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.0.RELEASE</version>
    </parent>

    <dependencies>
        <!-- base spring functionality -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
        </dependency>

        <!-- MySQL Connector -->
        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.13</version>
        </dependency>

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- nekohtml dependency -->
        <dependency>
            <groupId>net.sourceforge.nekohtml</groupId>
            <artifactId>nekohtml</artifactId>
        </dependency>
        <!-- auto config for spring stuff -->
        <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>
        <!-- JPA Java Persistence API, interface for saving/fetching data -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <!-- Dev tools for no-restart, etc -->
        
        <!-- <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency> -->
        
        <!-- Swagger Dependencies -->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.6.1</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.6.1</version>
        </dependency>
        <!-- Thymeleaf email dependency -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <!--Health Check -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!--Admin -->
        <dependency>
            <groupId>de.codecentric</groupId>
            <artifactId>spring-boot-admin-starter-client</artifactId>
            <version>2.1.6</version>
        </dependency>
        <!--Security -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
        </dependency>
        <!-- LiquiBase -->
        <dependency>
            <groupId>org.liquibase</groupId>
            <artifactId>liquibase-core</artifactId>
        </dependency>
        <!-- LiquiBase -->

        <dependency>
            <groupId>org.liquibase</groupId>
            <artifactId>liquibase-maven-plugin</artifactId>
            <version>3.4.1</version>
        </dependency>
        
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-java-sdk</artifactId>
            <version>1.11.600</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

    <properties>
        <java.version>1.8</java.version>
    </properties>
    <build>
        <...>
        <plugins>
            <plugin>
                <groupId>external.atlassian.jgitflow</groupId>
                <artifactId>jgitflow-maven-plugin</artifactId>
                <version>1.0-m5.1</version>
                <configuration>
                    <!-- No Maven deploy. -->
                    <noDeploy>true</noDeploy>
                    <!-- No merge, we'll do manual by pull request -->
                    <noReleaseMerge>true</noReleaseMerge>
                    <!-- No merge, we'll do manual by pull request -->
                    <noFeatureMerge>true</noFeatureMerge>
                    <!-- Keep branch for manual pull request -->
                    <keepBranch>true</keepBranch>
                    <flowInitContext>
                        <masterBranchName>stage</masterBranchName>
                        <developBranchName>develop</developBranchName>
                        <featureBranchPrefix>feature-</featureBranchPrefix>
                        <releaseBranchPrefix>release-</releaseBranchPrefix>
                        <hotfixBranchPrefix>hotfix-</hotfixBranchPrefix>
                        <versionTagPrefix>version-</versionTagPrefix>
                    </flowInitContext>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>build-info</goal>
                        </goals>
                </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-javadoc-plugin</artifactId>
                <configuration>
                    <!-- look online for options like specify directory -->
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <configuration>
                    <useSystemClassLoader>false</useSystemClassLoader>
                </configuration>
            </plugin>
            <!-- liquibase -->

            <plugin>
                <groupId>org.liquibase</groupId>
                <artifactId>liquibase-maven-plugin</artifactId>
                <version>3.4.1</version>
                <configuration>
                    <propertyFile>src/test/resources/liquibaseMaven.properties</propertyFile>
                </configuration>
                <!-- -->
                <dependencies>
                    <dependency>
                        <groupId>org.liquibase.ext</groupId>
                        <artifactId>liquibase-hibernate4</artifactId>
                        <version>3.5</version>
                    </dependency>
                    <dependency>
                        <groupId>org.springframework</groupId>
                        <artifactId>spring-beans</artifactId>
                        <version>4.1.7.RELEASE</version>
                    </dependency>
                    <dependency>
                        <groupId>org.springframework.data</groupId>
                        <artifactId>spring-data-jpa</artifactId>
                        <version>1.7.3.RELEASE</version>
                    </dependency>
                </dependencies>
                <!-- -->
            </plugin>
            <!-- liquibase -->

        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-releases</id>
            <url>https://repo.spring.io/libs-release</url>
        </repository>
        <repository>
            <id>....</id>
            <name>AWS Release Repository</name>
            <url>s3://.../...</url>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-releases</id>
            <url>https://repo.spring.io/libs-release</url>
        </pluginRepository>
    </pluginRepositories>
</project>```

下面是application.properties文件：

```spring.profiles.active=local

awsParameterStorePropertySource.enabled = true

spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect

api.s3.accessKey=...
api.s3.secretKey=...```

在进行故障排除时，以下是我尝试过的事情：

Maven 清理、Maven 安装、Maven 构建
从您的计算机中删除 .m2 文件检查 settings.xml 文件重新安装 .m2 文件并确保路径正确。
卸载并重新安装 eclipse
仔细检查 AWS 密钥
从您的计算机中完全删除 repo 并重新克隆
检查 AWS 中的区域，
检查您的 AWS CLI 配置中的凭证是否匹配
在 S3 存储桶中授予访问权限

你们对这个错误有什么建议吗？

【问题讨论】：

你试过看这个问题吗：stackoverflow.com/questions/44151982/…

标签： java spring amazon-web-services spring-boot maven

【解决方案1】：

我看到您正在尝试在 application.properties 中定义您的信誉。相反 - 尝试根据此处的 AWS Java 开发指南设置您的密钥：

Using credentials

我们在各种 AWS 服务指南中提供了许多 Spring BOOT 示例。这些示例应用通过将凭据放入名为 credentials 的文件中来处理凭据：C:\Users.aws\credentials（或对于 Linux - ~/.aws/credentials）。

要了解如何编写使用 AWS 服务的成功 Spring BOOT 应用程序，请参阅 Amazon Simple Notification Service Guide 中的此示例，该示例展示了如何开发 Spring BOOT具有 Sub/Pub 功能的应用：

Build a publish and subscription web application that translates messages

【讨论】：