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7.1 package The essence of a package is actually to create different folders / directories to hold class files 7.1.1 naming rules It can only contain numbers, letters, underscores and small dots, However, it cannot start with a number, keyword or reserved wordcom. Company name. Project name Business module name 7.1.2 common packages java.l ...

Title: This question is a blank filling question. You only need to calculate the result and use the output statement in the code to output the filled result. The glyphs of Chinese characters exist in the font library. Even today, the 16 # dot matrix font library is still widely used. 16. The font of dot matrix regards each Chinese character ...

I JMM memory model 1.1 what is the JMM memory model When multiple threads use the same shared variable: Step 1: copy a copy of the shared variable from the main memory to your own working memory, and modify the copy of the shared variable in your own working memory. Step 2: after modifying the value of the shared variable, write the new ...

  the golden three silver four is a good time for job hopping and salary increase. BOGO has sorted out a lot of high-frequency interview questions to help you find a better job. Oh, pay attention and thank you for your support. Object oriented interview questions 1. Talk about your understanding of object-oriented thinking? Process or ...

IO stream principle and stream classification How java IO streams work I/O is the abbreviation of Input stream / Output stream. I/O technology is a very practical technology for processing data transmission. Such as reading and writing files, network communication, etc.In Java program, the input / output operation of data is carried out in th ...

Spring Boot (14) -- Integrated Shiro 23. Introduction to Shiro 23.1 what is Shiro Apache Shiro is a security (permission) framework for JavaShiro can easily develop good enough applications, which can be used not only in Java se environment, but also in Java EE environmentShiro can complete: authentication, authorization, encryption, session ...

preface The linked list structure should be clear to everyone. LinkedList is implemented based on two-way linked list. The previous article briefly analyzed ArrayList, which is implemented based on array; This article will make a simple analysis of LinkedList. As long as you understand the structure of the linked list, the source code lo ...

1 what is generics 1.1 problems when not using generics Before JAVA introduced generics, you can store any data type Object by building a collection with the element type of Object. However, in the process of using the collection, you need to know the data type of each element. Otherwise, it is easy to cause ClassCastException exceptions. The ...

Question 1: ASCII code [problem description] It is known that the ASCII code of capital letter A is 65. What is the ASCII code of capital letter L? [answer submission] This is a question filled in with results. You just need to calculate the results and submit them. The result of this question is one An integer. Only fill in this intege ...

preface There are only two ways to create threads: inherit Thread or implement Runnable interface. However, both methods have a defect that they have no return value After Java 1.5, you can obtain a Future object containing the return value by submitting a Callable to the thread pool Limitations of Future interface When the thread of Future ...