1、問題

在使Springboot自動生成的專案框架時如果選擇了資料來源，比如選擇了mysql依賴，生成專案之後，在沒有任何的配置時啟動會報一下異常，執行程式後，控制檯輸出錯誤日誌：

2018-12-04 14:00:46.890  WARN 6592 --- [           main] o.a.c.loader.WebappClassLoaderBase       : The web application [ROOT] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:

 java.lang.Object.wait(Native Method)

 java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:142)

 com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:43)

2018-12-04 14:00:46.924  INFO 6592 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.

2018-12-04 14:00:46.928 ERROR 6592 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************

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).

2、SpringBoot啟動類

package com.thinkingcao;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;

/**
 * <pre>
 * @author cao_wencao
 * @date 2018年12月4日 下午1:59:57
 * </pre>
 */
@SpringBootApplication
public class MybatisAndDruidApplication {

	/**
	 * <pre>  
	 * @author cao_wencao
	 * @param args
	 * </pre>  
	 */
	public static void main(String[] args) {
		SpringApplication.run(MybatisAndDruidApplication.class, args);

	}

}

3、分析原因

這是因為spring boot預設會載入org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration類，DataSourceAutoConfiguration類使用了@Configuration註解向spring注入了dataSource bean。因為工程中沒有關於dataSource相關的配置資訊，當spring建立dataSource bean因缺少相關的資訊就會報錯。

因為我僅僅只是使用spring boot來寫一些很簡單的例子來學習它，在Application類上增加@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})

阻止spring boot自動注入dataSource bean

 4、解決辦法，二選其一

  方式一： 在Springboot啟動註解里加排除裝配DataSource資料來源， @SpringBootApplication(exclude={DataSourceAutoConfiguration.class})

package com.thinkingcao;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;

/**
 * <pre>
 * @author cao_wencao
 * @date 2018年12月4日 下午1:59:57
 * </pre>
 */
@SpringBootApplication(exclude={DataSourceAutoConfiguration.class})
public class MybatisAndDruidApplication {

	/**
	 * <pre>  
	 * @author cao_wencao
	 * @param args
	 * </pre>  
	 */
	public static void main(String[] args) {
		SpringApplication.run(MybatisAndDruidApplication.class, args);

	}

}

方式一：在@EnableAutoConfiguration裡排除裝配資料來源，@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})

package com.thinkingcao;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;

/**
 * <pre>
 * @author cao_wencao
 * @date 2018年12月4日 下午1:59:57
 * </pre>
 */
@SpringBootApplication
@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})
public class MybatisAndDruidApplication {

	/**
	 * <pre>  
	 * @author cao_wencao
	 * @param args
	 * </pre>  
	 */
	public static void main(String[] args) {
		SpringApplication.run(MybatisAndDruidApplication.class, args);

	}

}