Java core technology
In all fairness, Core Java (ie, Core Java) is not a particularly good book: the sample code is not rigorous enough, there are many comparisons to C/C++, and the language is not concise enough - the problem is that there is not a very good book for Java. Introductory books, compared with the same type of Java programming ideas, the core Java technology has at least done a lot of nonsense, keeping pace with the times (the Java programming idea is still before Java 6), and the generals are selected among the dwarfs, and the core Java technology is not bad. .
Effective Java
While there aren't any great introductory books for Java, that doesn't mean there aren't any great must-read books for Java. Effective Java is one of the best programming books I've ever read, it contains a lot of good Java programming practices and gives insightful advice on generics and concurrency, two pitfall-laden Java features that Java Father James Gosling prefaces the book: "I wish I had this book 10 years ago. Some might think I don't need any Java books, but I need this book."
Deep Understanding of the Java Virtual Machine (2nd Edition)
A very excellent and rare domestic masterpiece, the system introduces the Java virtual machine and related tools, and gives some tuning suggestions;
The Way of Java Programmer's Cultivation
Before this book, there was no Java book systematically detailing the new features of Java 7 (such as the new garbage collector, try using constructs and the invokedynamic directive), this book fills the gap;
Java Concurrent Programming Practice
A systematic and comprehensive introduction to Java concurrency, how to design data structures that support concurrency, and how to write correct concurrent programs;
Java Puzzlers
Contains a ton of Java pitfalls - so much so that one of the words I uttered the most while reading this book was WTF, and the point of this book is that it's a compendium of anti-patterns, Effective Java tells you how to write good Java programs, and Java Puzzlers tell you what a bad Java program looks like. Even more interesting is that the author of both books is Joshua Bloch.