weixin_42930033的博客

获取Bean工具类public class ApplicationContextProvider implements ApplicationContextAware { private ApplicationContext applicationContext; public ApplicationContext getApplicationContext() { ...

JAVA8新特性Optional优雅的判断空指针防止字符串出现空指针异常String text = fromNullable(searchRequest.getText()).or("");防止集合出现空指针 List<String> tags = fromNullable(searchRequest.getTags()).or(Collections.EMPTY_LIST);...

自定义@NotNull注解/* 配合hasNullOrEmpty使用*/@Target(ElementType.FIELD)@Retention(RetentionPolicy.RUNTIME)@Documented //javadocpublic @inteface NotNull{}/* 如果 arg为String类型:空或者null返回true 否则 当arg...