SpringBoot+Mybatis启动项目*required a single bean, but 2 were found*  异常问题为controller中存在多个相同的实例*************************** APPLICATION FAILED TO START *************************** Description: Field sysJobService in com.comet.controller.SysJobController required a single bean, but 2 were found: - sysJobServiceImpl: defined in file [G:\IdeaProject\comet\comet-quartz\target\classes\com\comet\service\impl\SysJobServiceImpl.class] - ISysJobService: defined in file [G:\IdeaProject\comet\comet-quartz\target\classes\com\comet\service\ISysJobService.class] Action: Consider marking one of the beans as @Primary, updating the consumer to accept multiple beans, or using @Qualifier to identify the bean that should be consumed 我个人在配置映射时没有制定到mapper包中才出现上述问题 改成这样就能成功启动并访问数据库

SpringBoot +Mybatis druid多数据源 配置依赖导入 <!-- springboot,druid 整合包 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency> <!--aop--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-aop</artifactId> </dependency> <!-- springboot,mybatis 整合包 --> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.2</version> </dependency> <!--mysql--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.46</version> </dependency>application.yml# 开发环境配置 server: # 服务器的HTTP端口，默认为80 port: 80 servlet: # 应用的访问路径 context-path: / tomcat: # tomcat的URI编码 uri-encoding: UTF-8 # tomcat最大线程数，默认为200 max-threads: 800 # Tomcat启动初始化的线程数，默认值25 min-spare-threads: 30 # Spring配置 spring: # 模板引擎 thymeleaf: mode: HTML encoding: utf-8 # 禁用缓存 cache: false profiles: active: druid # mybatis 配置 mybatis: mapper-locations: classpath:mybatis/mappers/*.xml configuration: map-underscore-to-camel-case: true #驼峰转换 use-generated-keys: true #获取数据库自增列 use-column-label: true #使用列别名替换列名 log-impl: org.apache.ibatis.logging.stdout.StdOutImpl default-executor-type: reuse #配置默认的执行器 cache-enabled: true #全局映射器启用缓存 type-aliases-package: com.comet #实体类配置别名 application-druid.yml# 数据源配置 spring: datasource: type: com.alibaba.druid.pool.DruidDataSource driverClassName: com.mysql.jdbc.Driver druid: # 主库数据源 master: url: jdbc:mysql://192.168.1.20:3306/comet1?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8 username: root password: root # 从库数据源 cluster: # 从数据源开关/默认关闭 enabled: true url: jdbc:mysql://192.168.1.21:3306/comet2?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8 username: root password: root # 初始连接数 initialSize: 5 # 最小连接池数量 minIdle: 10 # 最大连接池数量 maxActive: 20 # 配置获取连接等待超时的时间 maxWait: 60000 # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 timeBetweenEvictionRunsMillis: 60000 # 配置一个连接在池中最小生存的时间，单位是毫秒 minEvictableIdleTimeMillis: 300000 # 配置一个连接在池中最大生存的时间，单位是毫秒 maxEvictableIdleTimeMillis: 900000 # 配置检测连接是否有效 validationQuery: SELECT 1 FROM DUAL testWhileIdle: true testOnBorrow: false testOnReturn: false # 配置DruidStatFilter webStatFilter: enabled: true url-pattern: "/*" exclusions: "*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*" # 配置DruidStatViewServlet statViewServlet: enabled: true # 设置白名单，不填则允许所有访问 allow: url-pattern: /druid/* # 控制台管理用户名和密码 login-username: login-password: filter: stat: enabled: true # 慢SQL记录 log-slow-sql: true slow-sql-millis: 1000 merge-sql: true wall: config: multi-statement-allow: true代码枚举类 数据类型/** * @author Unclue_liu * @organization comet * @date 2019/9/3 0003 17:00 * @desc TODO 数据类型 */ public enum DataSourceType { /** * 主数据 */ MASTER, /** * 从数据 */ CLUSTER }注解类 自定义注解import com.comet.common.enums.DataSourceType; import java.lang.annotation.*; /** * @author Unclue_liu * @organization comet * @date 2019/9/3 0003 17:00 * @desc TODO 自定义多数据源切换注解，可以用于service类或者方法级别 方法级别优先级 > 类级别 */ @Target({ElementType.METHOD, ElementType.TYPE}) @Retention(RetentionPolicy.RUNTIME) @Documented @Inherited public @interface DataSource { /** * 切换数据源名称 */ DataSourceType value() default DataSourceType.MASTER; }druid 配置属性import com.alibaba.druid.pool.DruidDataSource; import lombok.Data; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Configuration; /** * @author Unclue_liu * @organization comet * @date 2019/10/18 0018 15:36 * @desc TODO druid 配置属性 */ @Data @Configuration public class DruidProperties { @Value("${spring.datasource.druid.initialSize}") private int initialSize; @Value("${spring.datasource.druid.minIdle}") private int minIdle; @Value("${spring.datasource.druid.maxActive}") private int maxActive; @Value("${spring.datasource.druid.maxWait}") private int maxWait; @Value("${spring.datasource.druid.timeBetweenEvictionRunsMillis}") private int timeBetweenEvictionRunsMillis; @Value("${spring.datasource.druid.minEvictableIdleTimeMillis}") private int minEvictableIdleTimeMillis; @Value("${spring.datasource.druid.maxEvictableIdleTimeMillis}") private int maxEvictableIdleTimeMillis; @Value("${spring.datasource.druid.validationQuery}") private String validationQuery; @Value("${spring.datasource.druid.testWhileIdle}") private boolean testWhileIdle; @Value("${spring.datasource.druid.testOnBorrow}") private boolean testOnBorrow; @Value("${spring.datasource.druid.testOnReturn}") private boolean testOnReturn; public DruidDataSource dataSource(DruidDataSource datasource) { /** 配置初始化大小、最小、最大 */ datasource.setInitialSize(initialSize); datasource.setMaxActive(maxActive); datasource.setMinIdle(minIdle); /** 配置获取连接等待超时的时间 */ datasource.setMaxWait(maxWait); /** 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 */ datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis); /** 配置一个连接在池中最小、最大生存的时间，单位是毫秒 */ datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis); datasource.setMaxEvictableIdleTimeMillis(maxEvictableIdleTimeMillis); /** * 用来检测连接是否有效的sql，要求是一个查询语句，常用select 'x'。如果validationQuery为null，testOnBorrow、testOnReturn、testWhileIdle都不会起作用。 */ datasource.setValidationQuery(validationQuery); /** 建议配置为true，不影响性能，并且保证安全性。申请连接的时候检测，如果空闲时间大于timeBetweenEvictionRunsMillis，执行validationQuery检测连接是否有效。 */ datasource.setTestWhileIdle(testWhileIdle); /** 申请连接时执行validationQuery检测连接是否有效，做了这个配置会降低性能。 */ datasource.setTestOnBorrow(testOnBorrow); /** 归还连接时执行validationQuery检测连接是否有效，做了这个配置会降低性能。 */ datasource.setTestOnReturn(testOnReturn); return datasource; } }数据源切换处理import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * @author Unclue_liu * @organization comet * @date 2019/10/18 0018 15:36 * @desc TODO 数据源切换处理 */ public class DynamicDataSourceContextHolder { public static final Logger log = LoggerFactory.getLogger(DynamicDataSourceContextHolder.class); /** * CONTEXT_HOLDER代表一个可以存放String类型的ThreadLocal对象， * 此时任何一个线程可以并发访问这个变量， * 对它进行写入、读取操作，都是线程安全的。 * 比如一个线程通过CONTEXT_HOLDER.set(“aaaa”);将数据写入ThreadLocal中， * 在任何一个地方，都可以通过CONTEXT_HOLDER.get();将值获取出来。 * 这里写入的就是数据库名， */ private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>(); /** * 设置数据源的变量 */ public static void setDataSourceType(String dsType) { log.info("切换到{}数据源", dsType); CONTEXT_HOLDER.set(dsType); } /** * 获得数据源的变量 */ public static String getDataSourceType() { return CONTEXT_HOLDER.get(); } /** * 清空数据源变量 */ public static void clearDataSourceType() { CONTEXT_HOLDER.remove(); } }动态数据源import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource; import javax.sql.DataSource; import java.util.Map; /** * @author Unclue_liu * @organization comet * @date 2019/10/18 0018 15:36 * @desc TODO 动态数据源 */ public class DynamicDataSource extends AbstractRoutingDataSource { public DynamicDataSource(DataSource defaultTargetDataSource, Map<Object, Object> targetDataSources) { super.setDefaultTargetDataSource(defaultTargetDataSource); super.setTargetDataSources(targetDataSources); super.afterPropertiesSet(); } @Override protected Object determineCurrentLookupKey() { return DynamicDataSourceContextHolder.getDataSourceType(); } }druid 配置多数据源import com.alibaba.druid.pool.DruidDataSource; import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder; import com.alibaba.druid.spring.boot.autoconfigure.properties.DruidStatProperties; import com.alibaba.druid.util.Utils; import com.comet.config.datasource.DynamicDataSource; import com.comet.common.enums.DataSourceType; import com.comet.config.properties.DruidProperties; import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.boot.web.servlet.FilterRegistrationBean; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Primary; import javax.servlet.*; import javax.sql.DataSource; import java.io.IOException; import java.util.HashMap; import java.util.Map; /** * @author Unclue_liu * @organization comet * @date 2019/10/18 0018 15:36 * @desc TODO druid 配置多数据源 */ @Configuration public class DataSourceConfig { @Bean @ConfigurationProperties("spring.datasource.druid.master") public javax.sql.DataSource masterDataSource(DruidProperties druidProperties) { DruidDataSource dataSource = DruidDataSourceBuilder.create().build(); return druidProperties.dataSource(dataSource); } @Bean @ConfigurationProperties("spring.datasource.druid.cluster") @ConditionalOnProperty(prefix = "spring.datasource.druid.cluster", name = "enabled", havingValue = "true") public javax.sql.DataSource clusterDataSource(DruidProperties druidProperties) { DruidDataSource dataSource = DruidDataSourceBuilder.create().build(); return druidProperties.dataSource(dataSource); } @Bean(name = "dynamicDataSource") @Primary public DynamicDataSource dataSource(javax.sql.DataSource masterDataSource, DataSource clusterDataSource) { Map<Object, Object> targetDataSources = new HashMap<>(); targetDataSources.put(DataSourceType.MASTER.name(), masterDataSource); targetDataSources.put(DataSourceType.CLUSTER.name(), clusterDataSource); return new DynamicDataSource(masterDataSource, targetDataSources); } /** * 去除监控页面底部的广告 */ @SuppressWarnings({ "rawtypes", "unchecked" }) @Bean @ConditionalOnProperty(name = "spring.datasource.druid.statViewServlet.enabled", havingValue = "true") public FilterRegistrationBean removeDruidFilterRegistrationBean(DruidStatProperties properties) { // 获取web监控页面的参数 DruidStatProperties.StatViewServlet config = properties.getStatViewServlet(); // 提取common.js的配置路径 String pattern = config.getUrlPattern() != null ? config.getUrlPattern() : "/druid/*"; String commonJsPattern = pattern.replaceAll("\\*", "js/common.js"); final String filePath = "support/http/resources/js/common.js"; // 创建filter进行过滤 Filter filter = new Filter() { @Override public void init(javax.servlet.FilterConfig filterConfig) throws ServletException { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { chain.doFilter(request, response); // 重置缓冲区，响应头不会被重置 response.resetBuffer(); // 获取common.js String text = Utils.readFromResource(filePath); // 正则替换banner, 除去底部的广告信息 text = text.replaceAll("<a.*?banner\"></a><br/>", ""); text = text.replaceAll("powered.*?shrek.wang</a>", ""); response.getWriter().write(text); } @Override public void destroy() { } }; FilterRegistrationBean registrationBean = new FilterRegistrationBean(); registrationBean.setFilter(filter); registrationBean.addUrlPatterns(commonJsPattern); return registrationBean; } }多数据源处理import com.comet.common.annotation.DataSource; import com.comet.common.utils.StringUtils; import com.comet.config.datasource.DynamicDataSourceContextHolder; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Pointcut; import org.aspectj.lang.reflect.MethodSignature; import org.springframework.core.annotation.Order; import org.springframework.stereotype.Component; import java.lang.reflect.Method; /** * @author Unclue_liu * @organization comet * @date 2019/10/18 0018 15:36 * @desc TODO 多数据源处理 */ @Aspect @Order(1) @Component public class DataSourceAspect { @Pointcut("@annotation(com.comet.common.annotation.DataSource)" + "|| @within(com.comet.common.annotation.DataSource)") public void dsPointCut() { } @Around("dsPointCut()") public Object around(ProceedingJoinPoint point) throws Throwable { DataSource dataSource = getDataSource(point); if (StringUtils.isNotNull(dataSource)) { DynamicDataSourceContextHolder.setDataSourceType(dataSource.value().name()); } try { return point.proceed(); } finally { // 销毁数据源 在执行方法之后 DynamicDataSourceContextHolder.clearDataSourceType(); } } /** * 获取需要切换的数据源 */ public DataSource getDataSource(ProceedingJoinPoint point) { MethodSignature signature = (MethodSignature) point.getSignature(); Class<? extends Object> targetClass = point.getTarget().getClass(); DataSource targetDataSource = targetClass.getAnnotation(DataSource.class); if (StringUtils.isNotNull(targetDataSource)) { return targetDataSource; } else { Method method = signature.getMethod(); DataSource dataSource = method.getAnnotation(DataSource.class); return dataSource; } } }至此多数据源配置完成。使用如果主从数据都使用，将从数据源改为true否则反之。这里配置druid的登录账户密码，如果没有配置则直接通过http://127.0.0.1/druid/index.html访问项目启动默认使用主数据源，如需切换从数据可使用如下方式：或