As a programmer, you can refer to the following classic books: Thinking in Java: The Bible of the Java programmer explains the core ideas of object-oriented programming in depth, which is very helpful for understanding the basics of the programming language. 2. Head First Java: A very popular introductory book to teach beginners how to quickly master the basics of Java through diagrams and humorous language. 3 << Effective Java >>: A must-have tool book for a Java programmer. It covers all kinds of best practices and techniques for improving your programming skills in the field of Java. 4.<< The Real Combat of Parallel programming in Java >>: It provides an in-depth explanation of the theory and practice of parallel programming in Java. At the same time, it provides a large number of cases and practices, which are very suitable for the reading of the programmers in the field of parallel programming in the field of parallel programming. 5 << The Real Combat of the Web Development >>: Covers all aspects of the Web development, including Servlet, JSP, Spring and other framework, as well as Web application testing and optimization. The content is very suitable for the development of the Web. Of course, in addition to the above books, there are many other excellent programming books that you can learn and refer to. It is also very helpful to choose one or more books that suit you according to your needs and level.