Java Interview Crash Course V1.0

Java Interview Crash Course V1.0 is an open-source Java interview question bank e-book compiled and released in April 2020 by an online technology community under the name Java R&D Corps, and it also circulates on platforms such as GitHub under the title Java Interview Handbook V1.0. The motivation was that many developers preparing to change jobs were gathering interview questions from everywhere, while available questions were scattered and answers varied in quality. The compilers therefore categorized questions collected from group members and themselves into a single review resource that could be read through as a whole. The volume is divided into about 26 categories, contains more than 2,000 questions, and runs to roughly 300,000 characters. It covers two main lines: the Java language itself and backend engineering practice. The language section includes Java OOP, String, collections, and multithreading and concurrency; the virtual machine section covers JVM memory structure, garbage collection, and class loading; the database and cache section covers MySQL, Redis, Memcached, and MongoDB; the framework and middleware section covers Spring Boot, Spring Cloud, MyBatis, Dubbo, ZooKeeper, RabbitMQ, Kafka, and Elasticsearch; it also touches on microservices, Linux, and data structures and other general fundamentals. The compilers position it as quick reference plus crash review, with questions arranged in Q&A form for concentrated module-by-module review before interviews. This is the first version, and the compilers say they will continue updating it and turn it into a question bank. It should be noted that this is a free electronic document compiled spontaneously by the community, with no formally published ISBN or publisher information, so readers must judge the accuracy and standard of expression of the answers for themselves.