spring boot 集成activiti如何能在启动是不配置数据库参数的情况下运行?报错

<?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">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>leave</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>leave</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</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-jdbc</artifactId>
            
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
            </dependency>
        
      <dependency>  
            <groupId>org.activiti</groupId>  
            <artifactId>activiti-spring-boot-starter-basic</artifactId>  
            <version>6.0.0</version>  
        </dependency>   
        <dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-starter-tomcat</artifactId>  
        </dependency>  
        
        <dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-web-services</artifactId>          
</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>
            </plugin>
        </plugins>
    </build>

</project>

------上面是spring boot 的pom.xml

在application.properties配置好数据库参数就可以正常运行。我的想法是在程序启动的时候不连接数据库，在程序运行的过程中按需连接到数据库，但我删除了数据可参数的时候就报错了！！！信息如下：

Description:

Cannot determine embedded database driver class for database type NONE

Action:

If you want an embedded database please put a supported one on the classpath. If you have database settings to be loaded from a particular profile you may need to active it (no profiles are currently active).

在网上找到的解决方案是添加注解(分别如下尝试都出错)：

1.-------------------------

@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class,HibernateJpaAutoConfiguration.class})

@SpringBootApplication

2.---------------------------------------
@SpringBootApplication(exclude={DataSourceAutoConfiguration.class})

3.------------------------------------
@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class,DataSourceTransactionManagerAutoConfiguration.class,HibernateJpaAutoConfiguration.class})

错误信息如下：

Description:

Parameter 0 of method springProcessEngineConfiguration in org.activiti.spring.boot.JpaProcessEngineAutoConfiguration$JpaConfiguration required a bean of type 'javax.sql.DataSource' that could not be found.
    - Bean method 'dataSource' not loaded because @ConditionalOnProperty (spring.datasource.jndi-name) did not find property 'jndi-name'
    - Bean method 'dataSource' not loaded because @ConditionalOnBean (types: org.springframework.boot.jta.XADataSourceWrapper; SearchStrategy: all) did not find any beans

Action:

Consider revisiting the conditions above or defining a bean of type 'javax.sql.DataSource' in your configuration