测试开发Gang

摘要： Spring Boot helps you to create stand-alone, production-grade **Spring-based** applications that you can run. Most Spring Boot applications need **ver 阅读全文

摘要： # Processing Data in Memory The Stream API is probably the second most important feature added to Java SE 8, after the lambda expressions. In a nutshe 阅读全文

摘要： # Storing Data The Collections Framework is the most widely used API of the JDK. > 集合不是数据类型，它是JDK的API，可以用来存储数据等，相当于数据结构。 the Collections Framework is 阅读全文

摘要： # Exception *Definition*: An *exception* is an event, which occurs during the execution of a program, that disrupts the normal flow of the program's i 阅读全文

摘要： # Packages Definition: A package is a grouping of related types providing access protection and name space management. Note that types refers to **cla 阅读全文

摘要： # 注解 注解的作用： - Information for the compiler — Annotations can be used by the compiler to detect errors or suppress warnings. - Compile-time and deploym 阅读全文

摘要： # Lambda Expression 有了Lambda Expression，就不用再写anonymous classes。 写Lambda，首先要找到它的类型。 There is a restriction on the type of a lambda expression: it has t 阅读全文

摘要： # 泛型 为什么需要泛型？generics enable types (classes and interfaces) to be parameters when defining classes, interfaces and methods. > 说白了就像Python动态语言的变量，是动态的， 阅读全文

摘要： # 接口 接口只能包含：constants, method signatures（abstract）, default methods, static methods, and nested types 方法体只存在于：default methods and static methods 接口不能实 阅读全文

摘要： # 继承 Java只有单继承，最顶级的父类是Object。 子类会继承父类的fields和methods，而不会继承constructors，因为constructors不属于methods，但是子类可以通过super调用父类的constructor。 子类继承父类的范围是：public、prote 阅读全文