基于自定义注解和AOP的Spring多数据源配置和使用

1 public class DynamicDataSource extends AbstractRoutingDataSource {
2
3 &＃64;Override
4 protected Object determineCurrentLookupKey() {
5 // 从自定义的位置获取数据源标识
6 return DynamicDataSourceHolder.getDataSource();
7 }
8
9 }

1 public class DynamicDataSourceHolder {2 /**3 * 注意&＃xff1a;数据源标识保存在线程变量中&＃xff0c;避免多线程操作数据源时互相干扰4 */5 private static final ThreadLocal THREAD_DATA_SOURCE &＃61; new ThreadLocal();6 7 public static String getDataSource() {8 return THREAD_DATA_SOURCE.get();9 }
10
11 public static void setDataSource(String dataSource) {
12 THREAD_DATA_SOURCE.set(dataSource);
13 }
14
15 public static void clearDataSource() {
16 THREAD_DATA_SOURCE.remove();
17 }
18
19 }

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1 &＃64;Service2 public class DataServiceImpl implements DataService {3 &＃64;Autowired4 private DataMapper dataMapper;5 6 &＃64;Override7 public List> getList1() {8 // 没有指定&＃xff0c;则默认使用数据源19 return dataMapper.getList1();
10 }
11
12 &＃64;Override
13 public List> getList2() {
14 // 指定切换到数据源2
15 DynamicDataSourceHolder.setDataSource("dataSource2");
16 return dataMapper.getList2();
17 }
18
19 &＃64;Override
20 public List> getList3() {
21 // 指定切换到数据源3
22 DynamicDataSourceHolder.setDataSource("dataSource3");
23 return dataMapper.getList3();
24 }
25 }

1 &＃64;Target({ TYPE, METHOD })
2 &＃64;Retention(RUNTIME)
3 public &＃64;interface DataSource {
4 String value();
5 }

1 public class DataSourceAspect {2 3 /**4 * 拦截目标方法&＃xff0c;获取由&＃64;DataSource指定的数据源标识&＃xff0c;设置到线程存储中以便切换数据源5 * 6 * &＃64;param point7 * &＃64;throws Exception8 */9 public void intercept(JoinPoint point) throws Exception {
10 Class target &＃61; point.getTarget().getClass();
11 MethodSignature signature &＃61; (MethodSignature) point.getSignature();
12 // 默认使用目标类型的注解&＃xff0c;如果没有则使用其实现接口的注解
13 for (Class clazz : target.getInterfaces()) {
14 resolveDataSource(clazz, signature.getMethod());
15 }
16 resolveDataSource(target, signature.getMethod());
17 }
18
19 /**
20 * 提取目标对象方法注解和类型注解中的数据源标识
21 *
22 * &＃64;param clazz
23 * &＃64;param method
24 */
25 private void resolveDataSource(Class clazz, Method method) {
26 try {
27 Class[] types &＃61; method.getParameterTypes();
28 // 默认使用类型注解
29 if (clazz.isAnnotationPresent(DataSource.class)) {
30 DataSource source &＃61; clazz.getAnnotation(DataSource.class);
31 DynamicDataSourceHolder.setDataSource(source.value());
32 }
33 // 方法注解可以覆盖类型注解
34 Method m &＃61; clazz.getMethod(method.getName(), types);
35 if (m !&＃61; null && m.isAnnotationPresent(DataSource.class)) {
36 DataSource source &＃61; m.getAnnotation(DataSource.class);
37 DynamicDataSourceHolder.setDataSource(source.value());
38 }
39 } catch (Exception e) {
40 System.out.println(clazz &＃43; ":" &＃43; e.getMessage());
41 }
42 }
43
44 }

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1 &＃64;Service2 // 默认DataServiceImpl下的所有方法均访问数据源13 &＃64;DataSource("dataSource1")4 public class DataServiceImpl implements DataService {5 &＃64;Autowired6 private DataMapper dataMapper;7 8 &＃64;Override9 public List> getList1() {
10 // 不指定&＃xff0c;则默认使用数据源1
11 return dataMapper.getList1();
12 }
13
14 &＃64;Override
15 // 覆盖类上指定的&＃xff0c;使用数据源2
16 &＃64;DataSource("dataSource2")
17 public List> getList2() {
18 return dataMapper.getList2();
19 }
20
21 &＃64;Override
22 // 覆盖类上指定的&＃xff0c;使用数据源3
23 &＃64;DataSource("dataSource3")
24 public List> getList3() {
25 return dataMapper.getList3();
26 }
27 }