ApplicationContextAware接口的实战应用

一 需求

系统要求导入报文数据，通过excel的形式，将数据导入系统，报文分为三种报文。

二 分析

报文分为3种，且报文的格式都是excel，报文可以作为一个抽象，并使用模板方法模式进行导入

三 实践

1. 新建抽象类IExcelOutYard

    public interface IExcelOutYard {
   
        String messageType();
   
        void loadExcel(Exchange exchange, String fileName, String camelFileParent);
    }
   

2. 新建抽象类ExcelOutYardAbstract实现IExcelOutYard ```` @Service public abstract class ExcelOutYardAbstract implements IExcelOutYard {

         private static Logger logger = LogManager.getCurrentClassLogger();
   
         @Override
         public void loadExcel(Exchange exchange, String fileName,String camelFileParent) {
             Object body = exchange.getIn().getBody();
             GenericFile<File> genericFile = (GenericFile<File>) body;
             File file = genericFile.getFile();
             this.analysis(file, fileName,camelFileParent);
         }
   
         private void analysis(File file, String fileName,String camelFileParent) {
             Workbook workbook = getWorkbook(file);
             Sheet sheet = workbook.getSheetAt(0);
             Set<String> messages = Sets.newConcurrentHashSet();
             // 1.校验数据
             validateMessage(sheet, messages, fileName);
             if (ObjectUtils.isNotEmpty(messages)) {
                 logger.error("校验不通过,原因[{}]", Joiner.on(";").join(messages));
             }
             // 2 组装对象
             List<Booking> bookings = contrustData(sheet, fileName,camelFileParent);
             // 3 插入数据
             saveAndUpdateData(bookings);
         }
   
   
         public List<Booking> contrustData(Sheet sheet, String fileName,String camelFileParent) {
             return null;
         }
   
         public void saveAndUpdateData(List<Booking> bookings) {
         }
   
         public void validateMessage(Sheet sheet, Set<String> messages, String fileName) {
         }
   
         private Workbook getWorkbook(File file) {
          -----
         }
   
   
         }
         ```
   

   3. 新建ExcelOutYardAccessGate,ExcelOutYardEmpty,ExcelOutYardSo继承抽象类ExcelOutYardAbstract

     ```
     @Service
     public class ExcelOutYardSo extends ExcelOutYardAbstract {
   
   
         @Override
         public String messageType() {
             return ExcelOutYardEnum.OUT_YARD_SO.name();
         }
     ```
   

   4. 新建ExcelOutYardManager 实现ApplicationContextAware接口

     ```
     public class ExcelOutYardManager implements ApplicationContextAware {
   
         Map<String,IExcelOutYard> excelOutYardMap;
   
         private Map<String, IExcelOutYard> getExcelOutYard() {
             if (excelOutYardMap == null) {
                 excelOutYardMap = new HashMap<String, IExcelOutYard>();
             }
             return excelOutYardMap;
         }
   
         public IExcelOutYard getImpleService(String messageType){
             return excelOutYardMap.get(messageType);
         }
   
         @Override
         public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
             Map<String, IExcelOutYard> beansOfType = applicationContext.getBeansOfType(IExcelOutYard.class);
             this.getExcelOutYard();
             for (IExcelOutYard iExcelOutYard:beansOfType.values()) {
                 excelOutYardMap.put(iExcelOutYard.messageType(),iExcelOutYard);
             }
         }
     }
     ```
   

5.调用

       ```
        String messageType = (String) exchange.getProperty("messageType");
        excelOutYardManager.getImpleService(messageType).loadExcel(exchange, fileName,camelFileParent);
        ```

三 结语

ApplicationContextAware接口在我前面的文章中，有所介绍，实现ApplicationContextAware接口后我们可以获得Bean容器中的所有bean，然后我们通过抽象类和他的实现，进行类型的映射，最终调用的时候，只需要传入类型码就可以了，从而实现了一个符合单一职责和开闭原则的设计。