Error getting a new connection Cause: org. apache. commons. dbcp. SQLNestedException

Problem description

Use today Acitivity establish ProcessEngineConfiguration The object is wrong

Error is as follows

org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server.)
### Error getting a new connection. Cause: org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server.)
### Cause: org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server.)

To analyze problems

1 It could be mysql Version driven problems
2 There may be a configuration error
3 I tested and inquired about the relevant errors on the Internet , Most of the reasons are mysql Version problem or configuration error , such as url Exact parameters , drive 8.0 Less cj, I am because of the version problem , I'm a local 8.0 The database of , however jar yes 5.7 Of

solve the problem

The relevant code is as follows

<?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>

    <groupId>com.wyh</groupId>
    <artifactId>Activiti01</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.0.RELEASE</version>
    </parent>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <activiti.version>6.0.0</activiti.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</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-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.activiti</groupId>
            <artifactId>activiti-spring-boot-starter-rest-api</artifactId>
            <version>${
    activiti.version}</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.18</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

To configure

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                    http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/contex
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">


    <!--dbcp Link pool -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql:///activiti?serverTimezone=UTC"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
        <property name="maxActive" value="3"/>
        <property name="maxIdle" value="1"/>
    </bean>

    <!-- By default  bean Of id   Fixed for  processEngineConfiguration-->
    <bean id="processEngineConfiguration"
          class="org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration">
        <!-- Configuration database related information -->
        <!-- Database driven 
        <property name="jdbcDriver" value="com.mysql.jdbc.Driver"/>-->
        <!-- Database link 
        <property name="jdbcUrl" value="jdbc:mysql:///activiti"/>-->
        <!-- Database user name 
        <property name="jdbcUsername" value="root"/>-->
        <!-- Database password 
        <property name="jdbcPassword" value="123456"/>-->
        <!-- Directly reference the link pool configured above -->
        <property name="dataSource" ref="dataSource"/>
        <!--actviti Strategy of database table generation 
        true -  If the corresponding table already exists in the database , So use... Directly ,
                If it doesn't exist , So it will create -->
        <property name="databaseSchemaUpdate" value="true"/>
    </bean>
</beans>

Test class

package com.wyh.test;

import org.activiti.engine.ProcessEngine;
import org.activiti.engine.ProcessEngines;
import org.activiti.engine.RepositoryService;
import org.junit.Test;

/** * @program: Activiti01 * @description: * @author:  Wei Yihe  * @createDate: 2022-06-22 21:59 **/

public class TestCreateTable {
    
    /** *  Use activiti Provides the default way to create mysql Table of  */
    @Test
    public void testCreateDbTable(){
    
        //  Need to use avtiviti Tool class provided  ProcessEngines , Usage method getDefaultProcessEngine
        // getDefaultProcessEngine Will default from resources The next read name is actviti.cfg.xml The file of 
        //  establish processEngine when , Will be created mysql Table of 
        ProcessEngine processEngine = ProcessEngines.getDefaultProcessEngine();
        System.out.println(processEngine);
    }

}

Start the test again after modification

You can see that the log information is already creating tables

view the database The table has been created normally