Mybatis连接MySQL数据库报错：“Communications link failure” 错误

1. pom.xml 配置

// 在 dependencies 中做如下配置
<dependencies>
	<dependency>
		<groupId>mysql</groupId>
		<artifactId>mysql-connector-java</artifactId>
		<version>5.1.30</version>
	</dependency>
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.1.3</version>
    </dependency>
    <dependency>
		<groupId>org.mybatis.generator</groupId>
		<artifactId>mybatis-generator-core</artifactId>
		<version>1.3.7</version>
	</dependency>
    <dependency>
		<groupId>org.mybatis.spring.boot</groupId>
		<artifactId>mybatis-spring-boot-starter</artifactId>
		<version>1.3.1</version>
    </dependency>
</dependencies>

// 在 build 中做如下配置
<build>
	<pluginManagement>
		</plugins>
			<plugin>
				<groupId>org.mybatis.generator</groupId>
				<artifactId>mybatis-generator-maven-plugin</artifactId>
				<version>1.3.7</version>
				<dependencies>
		            <dependency>
						<groupId>org.mybatis.generator</groupId>
						<artifactId>mybatis-generator-core</artifactId>
						<version>1.3.7</version>
		            </dependency>
		            <dependency>
		            	<groupId>mysql</groupId>
		            	<artifactId>mysql-connector-java</artifactId>
		            	<version>5.1.30</version>
		            </dependency>
				</dependencies>
				<executions>
					<execution>
						<id>mybatis generator</id>
						<phase>package</phase>
						<goals>
							<goal>generate</goal>
		 				</goals>
		 			</execution>
		 		</executions>
		 		<configuration>
		 			<!-- 允许移动生成的文件 -->
		 			<verbose>true</verbose>
	            	<!-- 允许自动覆盖文件  -->
	            	<overwrite>true</overwrite>
					<configurationFile>
						src/main/resources/mybatis-generator.xml
	            	</configurationFile>
				</configuration>
			</plugin>
        </plugins>
	</pluginManagement>
</build>

【注意】build 中 dependency 的内容可能不会自动 maven 下载导致变红，建议放在最上面的 dependencies 中先进行下载。

2. mybatis-generator.xml 配置

<!-- 数据库链接地址账号密码 -->
<jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/miaosha" userId="root" password="123456"/>

【注意】localhost换成127.0.0.1就有可能报 Communications link failure 的错误。

3. Edit Configuration 配置