Spring+Mybatis动态切换数据源的方法

  
    
    
    
      
        classpath*:/sqlMapperXml/*.xml
        classpath*:/sqlMapperXml/*/*.xml
      
    
    
    
    
    
      
        
        
          
          
        
      
    
  
  
  
  
    
    
    
    
  
  
    
    
  


  
  
    
  

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

/**
 * 
 * @ClassName: MultipleDataSource
 * @Description: 配置多个数据源

 * @author: yuzhu.peng
 * @date: 2018年1月12日 下午4:37:25
 */
public class MultipleDataSource extends AbstractRoutingDataSource {
  
  private static final ThreadLocal dataSourceKey = new InheritableThreadLocal();
  
  public static void setDataSourceKey(String dataSource) {
    dataSourceKey.set(dataSource);
  }
  
  @Override
  protected Object determineCurrentLookupKey() {
    return dataSourceKey.get();
  }
  
  public static void removeDataSourceKey() {
    dataSourceKey.remove();
  }
}

/*获取连接*/
  public Connection getConnection()
    throws SQLException {
    return determineTargetDataSource().getConnection();
  }

  protected DataSource determineTargetDataSource() {
    Assert.notNull(this.resolvedDataSources, "DataSource router not initialized");
    /*此处的determineCurrentLookupKey为抽象接口，获取具体的数据源名称*/
    Object lookupKey = determineCurrentLookupKey();
    DataSource dataSource = (DataSource)this.resolvedDataSources.get(lookupKey);
    if ((dataSource == null) && (((this.lenientFallback) || (lookupKey == null)))) {
      dataSource = this.resolvedDefaultDataSource;
    }
    if (dataSource == null) {
      throw new IllegalStateException("Cannot determine target DataSource for lookup key [" + lookupKey + "]");
    }
    return dataSource;
  }
  /*抽象接口：也即我们的multipleDataSource实现的接口*/
  protected abstract Object determineCurrentLookupKey();

import java.lang.reflect.Proxy;

import org.apache.commons.lang.ClassUtils;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.core.annotation.Order;

/**
 * 数据源切换AOP
 * 
 * @author yuzhu.peng
 * @since 2018-01-15
 */
@Aspect
@Order(1)
public class MultipleDataSourceInterceptor {
  /**
   * 拦截器对所有的业务实现类请求之前进行数据源切换 特别注意,由于用到了多数据源,Mapper的调用最好只在*ServiceImpl,不然调用到非默认数据源的表时,会报表不存在的异常
   * 
   * @param joinPoint
   * @throws Throwable
   */
  @Before("execution(* com.xxxx.platform.service..*.*ServiceImpl.*(..))")
  public void setDataSoruce(JoinPoint joinPoint)
    throws Throwable {
    Class<?> clazz = joinPoint.getTarget().getClass();
    String className = clazz.getName();
    if (ClassUtils.isAssignable(clazz, Proxy.class)) {
      className = joinPoint.getSignature().getDeclaringTypeName();
    }
    // 对类名含有serverA的设置为serverA数据源,否则默认为后台的数据源
    if (className.contains(".serverA.")) {
      MultipleDataSource.setDataSourceKey(DBConstant.DATA_SOURCE_serverA);
    }
    else if (className.contains(".serverB.")) {
      MultipleDataSource.setDataSourceKey(DBConstant.DATA_SOURCE_serverB);
    }
    else {
      MultipleDataSource.setDataSourceKey(DBConstant.DATA_SOURCE_OP);
    }
  }
  
  /**
   * 当操作完成时,释放当前的数据源 如果不释放,频繁点击时会发生数据源冲突,本是另一个数据源的表,结果跑到另外一个数据源去,报表不存在
   * 
   * @param joinPoint
   * @throws Throwable
   */
  @After("execution(* com.xxxx.service..*.*ServiceImpl.*(..))")
  public void removeDataSoruce(JoinPoint joinPoint)
    throws Throwable {
    MultipleDataSource.removeDataSourceKey();
  }
}