業務中台設計实例 - CSDN

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1. /**
   
2. * 扩大点扫描、注册
   
3. */
   
4. public class ExtPointBeanPostProcess implements BeanPostProcessor {
   
5. @Override
   
6. public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
   
7. return bean;
   
8. }
   
9. /**
   
10. * 辨認扩大点实例, 并完成扩大点注册
    
11. * 1.扩大点必需实現IExtensionPoint接口
    
12. * 2.强迫请求扩大点接口名必需以ExtPt末端
    
13. */
    
14. @Override
    
15. public Object台中機車借款， postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
    
16. if (bean instanceof IExtensionPoint) {
    
17. IExtensionPoint extPoint = (IExtensionPoint) bean;
    
18. 
    
19. ExtensionCoordinate coordinate = parseExtensionCoordinate(bean.getClass());
    
20. IExtensionPoint oldValue = ExtensionManager.getInstance()
    
21. .registerExtPoint(coordinate, extPoint);
    
22. if (Objects.nonNull(oldValue)) {
    
23. throw new MidFrameworkException("Duplicate registration for :" + coordinate);
    
24. }
    
25. }
    
26. return bean;
    
27. }
    
28. private ExtensionCoordinate parseExtensionCoordinate(Class<?> targetBean) {
    
29. // 扩大点接口
    
30. Optional<Class> extPointClass = checkExtensionPoint(targetBean);
    
31. if (!extPointClass.isPresent()) {
    
32. throw new MidFrameworkException(
    
33. String.format("The name of ExtensionPoint for %s must be end with %s", targetBean, IExtensionPoint.EXT_POINT_NAMING));
    
34. }
    
35. // 解析@Extension注解
    
36. AnnotationAttributes attrs = AnnotatedElementUtils.getMergedAnnotationAttributes(targetBean, Extension.class);
    
37. String bizCode = attrs.getString("bizCode");
    
38. String name = attrs.getString("name");
    
39. String description = attrs.getString("description");
    
40. return ExtensionCoordinate.builder()
    
41. .bizCode(bizCode)
    
42. .extensionPoint(extPointClass.get().getName())
    
43. .name(name)
    
44. .description(description)
    
45. .build();
    
46. }
    
47. private Optional<Class> checkExtensionPoint(Class<?> targetBean) {
    
48. Class[] interfaces = targetBean.getInterfaces();
    
49. if (interfaces == null || interfaces.length == 0) {
    
50. throw new MidFrameworkException("No extension point interface for " + targetBean);
    
51. }
    
52. // 扩大点接口名必需以ExtPt末端
    
53. return Arrays.stream(interfaces)
    
54. .filter(ext -> ext.getSimpleName().endsWith(IExtensionPoint.EXT_POINT_NAMING))
    
55. .findFirst();
    
56. }
    
57. }

複製代碼

颠末以上步调，體系已启動完成，而且所有的扩大点也都完成为了注册。剩下的就是怎样去挪用扩大点法子了！因为统一個扩大点的所有实例多是统一個名字，好比都叫
BuyExtPointImpl，明顯不克不及經由過程Spring的依靠注入来挪用。究竟上，扩大点实例的挪用，都是同一走扩大点履行器，其内部封装了扩大点查找逻辑和履行逻辑，代码注释應當写得比力清晰了。

1. /**
   
2. * 扩大点实例履行器: 封装扩大点查找计谋及法子挪用
   
3. */
   
4. public class ExtensionExecutor  {
   
5. private ExtensionExecutor() {
   
6. throw new IllegalStateException("No instance");
   
7. }
   
8. /**
   
9. * 有返回值
   
10. *
    
11. * @param targetClass 扩大点类名
    
12. * @param bizId       营業身份
    
13. * @param exeFunction 必要挪用的扩大点法子
    
14. */
    
15. public static <R, T> R execute(BizId bizId, Class<T> targetClass, Function<T, R> exeFunction) {
    
16. T component = findComponent(bizId, targetClass);
    
17. return exeFunction.apply(component);
    
18. }
    
19. /**
    
20. * 無返回值
    
21. *
    
22. * @param targetClass 扩大点类名
    
23. * @param bizId       营業身份
    
24. * @param exeConsumer 必要挪用的扩大点法子
    
25. */
    
26. public static <T> void consume(BizId bizId, Class<T> targetClass, Consumer<T> exeConsumer) {
    
27. T component = findComponent(bizId, targetClass);
    
28. exeConsumer.accept(component);
    
29. }
    
30. /**
    
31. * 切确查找扩大点: 先看是不是有营業实現的扩大点；若没有，再看是不是有平台默许实現
    
32. */
    
33. @SuppressWarnings("unchecked")
    
34. private static <T> T findComponent(BizId bizId, Class<T> targetClass) {
    
35. ExtensionCoordinate bizCoordinate = ExtensionCoordinate.of(bizId.getBizCode(), targetClass.getName());
    
36. IExtensionPoint extension = ExtensionManager.getInstance().findExtPoint(bizCoordinate);
    
37. if (Objects.isNull(extension)) {
    
38. ExtensionCoordinate systemCoordinate = ExtensionCoordinate.of(IExtensionPoint.SYSTEM_BIZ_CODE,
    
39. targetClass.getName());
    
40. extension = ExtensionManager.getInstance().findExtPoint(systemCoordinate);
    
41. }
    
42. if (Objects.isNull(extension)) {
    
43. throw new MidFrameworkException("Not found extension: " + bizCoordinate);
    
44. }
    
45. return (T) extension;
    
46. }
    
47. }

複製代碼

下面以一個单测为例演示扩大点的履行 ExtensionExecutor.execute()

1. @Test
   
2. public void testTaobaoExt() {
   
3. BizId bizId = new BizId("com.taobao");
   
4. int promotion = ExtensionExecutor.execute(bizId, PromotionCalcExtPoint.class,
   
5. PromotionCalcExtPoint::calcPromotion);
   
6. Assert.539版路單，assertEquals(promotion, 80);
   
7. }
   
8. @Test
   
9. public void testTmallExt() {
   
10. BizId bizId = new BizId("com.tmall");
    
11. int promotion = ExtensionExecutor.exec君綺PTT，ute(隱形矯姿帶,bizId, PromotionCalcExtPoint.class,
    
12. PromotionCalcExtPoint::calcPromotion);
    
13. Assert.assertEquals(promotion, 90);
    
14. }

複製代碼

上面2末節，已把扩大点注册和扩大点履行，触及到的数据模子、運行機制論述清晰了。這里再補一幅圖来個更直观感觉。