Springboot启动报错：Failed to bind properties under spring.datasource to javax.sql.DataSource

项目结构：

DruidConfig：

package com.lucifer.springboot.config;import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;import javax.sql.DataSource;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;@Configuration
public class DruidConfig {@ConfigurationProperties(prefix = "spring.datasource")@Beanpublic DataSource druid(){return  new DruidDataSource();}//配置Druid的监控//1、配置一个管理后台的Servlet@Beanpublic ServletRegistrationBean statViewServlet(){ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");Map<String,String> initParams = new HashMap<>();initParams.put("loginUsername","admin");initParams.put("loginPassword","123456");initParams.put("allow","");//默认就是允许所有访问//initParams.put("deny","192.168.15.21");bean.setInitParameters(initParams);return bean;}//2、配置一个web监控的filter@Beanpublic FilterRegistrationBean webStatFilter(){FilterRegistrationBean bean = new FilterRegistrationBean();bean.setFilter(new WebStatFilter());Map<String,String> initParams = new HashMap<>();initParams.put("exclusions","*.js,*.css,/druid/*");bean.setInitParameters(initParams);bean.setUrlPatterns(Arrays.asList("/*"));return  bean;}
}

pom.xml:

<?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.lucifer</groupId><artifactId>spring-boot-data-jdbc</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>spring-boot-data-jdbc</name><description>Demo project for Spring Boot</description><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.0.5.RELEASE</version><relativePath/> <!-- lookup parent from repository --></parent><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding><java.version>1.8</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency><!--引入druid数据源--><!-- https://mvnrepository.com/artifact/com.alibaba/druid --><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.8</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</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>

SpringbootMybatisApplication:启动类

package com.lucifer.springboot;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication
public class SpringbootMybatisApplication {public static void main(String[] args) {SpringApplication.run(SpringbootMybatisApplication.class, args);}
}

（ps:如果pom.xml中加了这个<scope>runtime</scope>，application.yml中配置的driver-class-name可能会报红。）

application.yml:

spring:datasource:username: rootpassword: 123456url: jdbc:mysql://localhost:3306/jdbcdriver-class-name: com.mysql.jdbc.Drivertype: com.alibaba.druid.pool.DruidDataSourceinitialSize: 5minIdle: 5maxActive: 20maxWait: 60000timeBetweenEvictionRunsMillis: 60000minEvictableIdleTimeMillis: 300000validationQuery: SELECT 1 FROM DUALtestWhileIdle: truetestOnBorrow: falsetestOnReturn: falsepoolPreparedStatements: true#   配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙filters: stat,wall,log4jmaxPoolPreparedStatementPerConnectionSize: 20useGlobalDataSourceStat: trueconnectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
#    schema:
#      - classpath:department.sql

启动项目，控制台报错：

查看报错信息： Reason: org/apache/log4j/Logger，提示原因在于log4j。

 注：  在springboot1.5的版本中，使用的是spring4.x，而springboot2.x使用的是spring5.x，在spring5.x后，官方弃用了log4j，而建议并使用log4j2，因此要么降低版本使用spring4.x的spring boot版本，要么额外去引入log4j的jar包。

解决办法:

(1)办法一：增加log4j的包

<dependency><groupId>log4j</groupId><artifactId>log4j</artifactId><version>1.2.17</version>
</dependency>

（2）办法二：将spring-boot-starter-parent版本2.0.5改成1.5.15，改低一些。

更改后，再次启动，控制台无报错信息。