embedded database (H2, HSQL or Derby), please put it on the classpath

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).

这个错误网上有很多种情况，但是我遇到的有两个：

第一种：进程占用；

这个错误是看同一个项目进程被占用，如果有的话，关闭就行。

第二种：pom文件资源配置有问题

        <!-- 资源目录 -->
        <resources>
            <resource>
                <!-- 设定主资源目录  -->
                <directory>src/main/java</directory>
                <!-- maven default生命周期，process-resources阶段执行maven-resources-plugin插件的resources目标处理主资源目下的资源文件时，只处理如下配置中包含的资源类型 -->
                <includes>
                    <include>**/*.xml</include>
                </includes>
                <!-- maven default生命周期，process-resources阶段执行maven-resources-plugin插件的resources目标处理主资源目下的资源文件时，不处理如下配置中包含的资源类型（剔除下如下配置中包含的资源类型）-->
                <excludes>
                    <exclude>**/*.yml</exclude>
                </excludes>
                <!-- maven default生命周期，process-resources阶段执行maven-resources-plugin插件的resources目标处理主资源目下的资源文件时，指定处理后的资源文件输出目录，默认是${build.outputDirectory}指定的目录-->
                <!--<targetPath>${build.outputDirectory}</targetPath> -->
                <!-- maven default生命周期，process-resources阶段执行maven-resources-plugin插件的resources目标处理主资源目下的资源文件时，是否对主资源目录开启资源过滤 -->
                <filtering>true</filtering>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.yml</include>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>

我出现的问题是第二种，没有配置src/main/resources这个目录的资源