更改 application.properties 后 Spring-Boot 应用程序无法启动

Question

我的 application.properties 文件中有以下配置

#database-configurations
spring.datasource.url=jdbc:mysql://localhost:3306/exam
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class=com.mysql.cj.jdbc.Driver

#jpa-configurations
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL8Dialect
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.format_sql=true

但是应用程序无法使用这些配置启动。之前工作得很好。恰巧我误删了application.properties文件中的配置并启动了spring-boot应用程序。启动失败，显然是application.properties中没有配置。该错误表明无法找到数据源 URL。但现在即使我在 application.properties 文件中正确输入所有详细信息，我仍然遇到相同的错误。它似乎没有从 application.properties 文件中读取值。它被我从 application.properties 中删除的配置设置卡住了。

我收到以下错误

Error starting ApplicationContext. To display the condition evaluation report re-run your application with 'debug' enabled.
[2m2023-01-22T14:55:32.603+05:30[0;39m [31mERROR[0;39m [35m152247[0;39m [2m---[0;39m [2m[  restartedMain][0;39m [36mo.s.b.d.LoggingFailureAnalysisReporter  [0;39m [2m:[0;39m 

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.

Reason: Failed to determine a suitable driver class


Action:

Consider the following:
    If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.
    If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).

Spring Tool Suit 在“additional-spring-configuration-metadata”文件的 META-INF 文件夹中添加了以下几行。

{"properties": [{
  "name": "spring.datasource.driver-class",
  "type": "java.lang.String",
  "description": "A description for 'spring.datasource.driver-class'"
}]}

以下是我的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 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>3.0.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.exam</groupId>
    <artifactId>examserver</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>examserver</name>
    <description>backend code for exam portal</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </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>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

Answer 1

启动 ApplicationContext 时出错。要显示条件评估报告，请在启用“调试”的情况下重新运行您的应用程序。 [2m2024-12-15T19:37:36.218+05:30[0;39m [31mERROR[0;39m [35m9864[0;39m [2m--- [Spring_Boot_Rest_API_Project]] [ restartedMain] [0;39m[36mo.s.b.d.LoggingFailureAnalysisReporter [0;39m [2m:[0;39m

Answer 2

application.properties 文件必须位于 src/main/resources 文件夹中。