Overview:
As a JAVA WEB engineer, when I first started my job, my seniors told me that as long as I use the framework well, I will be successful in my work, and take the framework as the creed of development. However, when I was just starting out, there was absolutely no concept of framework in my mind. After I gradually got the concept of framework, people were bound by the framework and could not jump out. Later, after having a certain work experience, I found that only by deeply understanding the core technology of Java can we write high-performance and high-quality code.
After reading:
Recalling the years of studying on campus, what I learned in school was very basic knowledge of Java. Many of the "new features" that have appeared in Java for many years were only exposed after leaving the school, such as generics and Chinese variable names. Because it is impossible for teachers in school to teach you new knowledge to keep up with the times, a good book is very precious. "Core Java Technology for Busy People" is a good book that is at the forefront of the times. As can be seen from the catalogue, it introduces in detail several unique new features of Java 8:
- New time/date APIs: Java 8 includes a new set of time and date APIs under the package java.time. The new date API is similar to the open source Joda-Time library, but not exactly the same, with Date and Calendar starting a countdown.
- Improvement of generics: From now on, List and Map in generics can also contain generics, and it is more convenient to encapsulate a method for parsing Json in a predetermined format.
- Lambda Expression: A Lambda expression represents a block of code that can be executed at a later point in time. In other words, functions can be arguments to methods.
- Multiple annotations: Annotation annotation supports multiple annotations in Java 8.
Try Chapter 3: Interfaces and Lambda Expressions
One of the big highlights of Java 8 is the introduction of lambda expressions, which make the code designed with it more concise. When developers write Lambda expressions, they are also compiled into a functional interface. Using lambda expressions not only makes the code simpler, but also readable, and most importantly, the code size is also greatly reduced.
In this chapter, the author gradually introduces lambda expressions from the explanation of interfaces. In lambda expressions, in addition to explaining the basic syntax and usage, he also explains the ins and outs of the name lambda, that is, "lambda expression" (lambda expression) It is an anonymous function. The Lambda expression is named after the lambda calculus in mathematics, which directly corresponds to the lambda abstraction. It is an anonymous function, that is, a function without a function name. It is really wonderful to be told by the master about the ups and downs, the weightlifting is light, and there are many examples to explain.
Summarize: