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How to switch multiple data sources through annotations in spring? aiming at this problem, this article introduces the corresponding analysis and solution in detail, hoping to help more partners who want to solve this problem to find a more simple and feasible method.

The first step, configure the data source

The second step is to define the annotations used to cut the library, and enumerate classes

@ Target ({ElementType.METHOD}) @ Retention (RetentionPolicy.RUNTIME) public @ interface Dataswitch {Datatype value () default Datatype.master;} public enum Datatype {master ("masterDataSource"), slave ("slaveDataSource"); private String value; Datatype (String name) {this.value = name;} public String getValue () {return value;} public void setValue (String value) {this.value = value;}}

The third step is to define a tool class for the variable of the current thread, which is used to set the corresponding data source name

Public class DynamicDataSourceHolder {private static final ThreadLocal threadLocal = new ThreadLocal (); public static String getThreadLocal () {return threadLocal.get ();} public static void setThreadLocal (String name) {threadLocal.set (name);} public static void clear () {threadLocal.remove ();}}

The fourth step is to create a subclass of AbstactRoutingDataSource and override the determineCurrentLockupKey method

Public class DynamicDataSource extends AbstractRoutingDataSource {protected Object determineCurrentLookupKey () {System.out.println (DynamicDataSourceHolder.getThreadLocal ()); return DynamicDataSourceHolder.getThreadLocal ();}}

Step 5, configure multiple data sources to use the DynamicDataSource we created

The sixth step is to configure the aspect, get the name of the data source of the annotation configuration before operating the database method, and return

@ Component@Aspect@Order (0) public class DataSourceAspect {@ Pointcut ("execution (* xin.youhuila.sorceswitch.service..* (..)") Public void aspect () {} @ Before ("aspect ()") public void before (JoinPoint joinPoint) {Class clazz = joinPoint.getTarget () .getClass (); Method [] method = clazz.getMethods (); Dataswitch dataswitch = null; boolean is = false For (Method m:method) {/ / here it is best to obtain whether the calling method contains comments by signature instead of traversing each method. Refer to http://www.gitout.cn/?p=2398 if (m.isAnnotationPresent (Dataswitch.class)) {dataswitch = m.getAnnotation (Dataswitch.class); DynamicDataSourceHolder.setThreadLocal (dataswitch.value (). GetValue ()) Is = true;}} if (! is) {DynamicDataSourceHolder.setThreadLocal (Datatype.master.getValue ());} @ After ("aspect ()") public void after () {DynamicDataSourceHolder.clear ();}}

Step 7, use the

@ Servicepublic class DemoService {@ Autowired DemoMapper demoMapper; @ Dataswitch (Datatype.master) public void select () {List d = demoMapper.select (); for (Demo demo:d) {System.out.println (demo);}

-- http://www.gitout.cn/?p=2398 article implementation-

/ * data source aspect * / @ Aspect@Componentpublic class DynamicDataSourceAspect {@ Pointcut ("@ annotation (com...datasource.DynamicDataSourceAnnotation)") public void pointCut () {} @ Before ("pointCut ()") public void testBefore (JoinPoint point) {/ / get the currently accessed class Class className = point.getTarget (). GetClass () DynamicDataSourceAnnotation dataSourceAnnotation = className.getAnnotation (DynamicDataSourceAnnotation.class); String dataSource = DataSourceConst.DB_ACTIVITY; / / priority: method > Class > DB_ACTIVITY if (dataSourceAnnotation! = null) {dataSource = dataSourceAnnotation.dataSource ();} String methodName = point.getSignature () .getName () / / get the type of parameter of the method Class [] argClass = ((MethodSignature) point.getSignature ()) .getParameterTypes (); try {Method method = className.getMethod (methodName, argClass) If (method.isAnnotationPresent (DynamicDataSourceAnnotation.class)) {DynamicDataSourceAnnotation annotation = method.getAnnotation (DynamicDataSourceAnnotation.class); dataSource = annotation.dataSource ();}} catch (Exception e) {e.printStackTrace () } DataSourceContextHolder.setDataSourceType (dataSource);} @ After ("pointCut ()") public void testAfter (JoinPoint point) {/ / get the currently visited class Class className = point.getTarget () .getClass (); DynamicDataSourceAnnotation dataSourceAnnotation = className.getAnnotation (DynamicDataSourceAnnotation.class) If (dataSourceAnnotation! = null) {/ / access method name String methodName = point.getSignature () .getName (); / / get the type of method parameter Class [] argClass = ((MethodSignature) point.getSignature ()) .getParameterTypes () String dataSource = DataSourceConst.DB_ACTIVITY; try {Method method = className.getMethod (methodName, argClass); if (method.isAnnotationPresent (DynamicDataSourceAnnotation.class)) {DynamicDataSourceAnnotation annotation = method.getAnnotation (DynamicDataSourceAnnotation.class) DataSource = annotation.dataSource ();}} catch (Exception e) {e.printStackTrace () } if (dataSource! = null & &! DataSourceConst.DB_ACTIVITY.equals (dataSource)) {DataSourceContextHolder.clearDataSourceType () }} this is the answer to the question about how to switch multiple data sources through annotations in spring. I hope the above content can be of some help to you. If you still have a lot of doubts to be solved, you can follow the industry information channel for more related knowledge.

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