package com.gomecar.index.datasource;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;/*** 数据源切换注解* @author xiaotian**/
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE,ElementType.METHOD})
public @interface DataSource {String value() default "read";}

package com.gomecar.index.datasource;import java.lang.reflect.Method;
import org.apache.log4j.Logger;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.reflect.MethodSignature;/*** 用于数据库读写分离的切面* @author xiaotian**/
@Aspect
public class DataSourceAspect {//日志private Logger logger = Logger.getLogger(this.getClass());/*** 拦截目标方法，获取由@DataSource指定的数据源标识，设置到线程存储中以便切换数据源** @param point* @throws Exception*/public void intercept(JoinPoint point) throws Exception {Class<?> target = point.getTarget().getClass();MethodSignature signature = (MethodSignature) point.getSignature();for (Class<?> clazz : target.getInterfaces()) {resolveDataSource(clazz, signature.getMethod());}resolveDataSource(target, signature.getMethod());}/*** 提取目标对象方法注解和类型注解中的数据源标识** @param clazz* @param method*/private void resolveDataSource(Class<?> clazz, Method method) {try {Class<?>[] types = method.getParameterTypes();// 默认使用类型注解dataSourcePointcutdataSourcePointcutif (clazz.isAnnotationPresent(DataSource.class)) {DataSource source = clazz.getAnnotation(DataSource.class);DynamicDataSourceHolder.putDataSource(source.value());}// 方法注解可以覆盖类型注解Method m = clazz.getMethod(method.getName(), types);if (m != null && m.isAnnotationPresent(DataSource.class)) {DataSource source = m.getAnnotation(DataSource.class);DynamicDataSourceHolder.putDataSource(source.value());}} catch (Exception e) {logger.error("切换数据源error", e);}}//通知public void before(JoinPoint point){Object target = point.getTarget();String method = point.getSignature().getName();//反射获取接口Class<?>[] classz = target.getClass().getInterfaces();//获取返回值类型 Class<?>[] parameterTypes = ((MethodSignature) point.getSignature()).getMethod().getParameterTypes();try {//获取方法Method m = classz[0].getMethod(method, parameterTypes);//根据方法上注解  获取只读数据库连接池 或者只写数据库连接池if (m != null && m.isAnnotationPresent(DataSource.class)) {//根据注解值获取数据库连接池DataSource data = m.getAnnotation(DataSource.class);DynamicDataSourceHolder.putDataSource(data.value());System.out.println(data.value());}} catch (Exception e) {// TODO: handle exception
        }}
}

package com.gomecar.index.datasource;import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
/*** 动态获取数据源* @author xiaotian**/
public class DynamicDataSource extends AbstractRoutingDataSource {@Overrideprotected Object determineCurrentLookupKey() {return DynamicDataSourceHolder.getDataSouce();}}

package com.gomecar.index.datasource;
/*** 数据库连接池 持有者* 将数据库连接绑定到当前线程* @author xiaotian**/
public class DynamicDataSourceHolder {//绑定当前线程public static final ThreadLocal<String> holder = new ThreadLocal<String>();//设置数据源public static void putDataSource(String name) {holder.set(name);}//获取数据源public static String getDataSouce() {return holder.get();}
}