Life with Programming

 ?: 이후가 기본 값(default) @Value("#{systemProperties['mongodb.port'] ?: 27017}") - 그 외 * PropertySourcesPlaceholderConfigurer * ${property:default value} from : https://www.mkyong.com/spring3/spring-value-default-value/

    @Bean     public ResourceAwareItemReaderItemStream<A> flatFileReader() {         FlatFileItemReader<A> fileReader = new FlatFileItemReader<>();         fileReader.setEncoding("UTF-8");         fileReader.setLineMapper(LINEMAPPER);         return fileReader;     }     @Bean     @StepScope     public ItemReader<A> multipleFileReader(         @Value("#{jobParameters[target]?:null}") String target     ) throws IOException {         String filePath = ~~~;         filePath += "/*";         ClassLoader loader = this.getClass().getClassLoader();         PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver(loader);         MultiResourceItemReader<A> reader = new M...