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APIJSAON (I: Introduction)backgroundDue to various wonderful abbreviations, chaotic naming, outdated documents, out of sync with interfaces, unstable or arbitrary changes of data types, hundreds or even thousands of chaotic status codes, all kinds of wrangling between the front end and the back end, cumbersome whole development process, long de ...

Day4: enter, if, switch When implementing branch judgment, a good habit is to put the judgment with high matching success rate in front, which can improve efficiencyIn the expression judgment, we try to use the determined value to judge with the uncertain value Execution process in the program: Sequencing: starting from the main method ...

catalogue 1, System introduction 1. Development environment 2. Technical selection 3. System functions 4. Database files 5. System screenshot 2, System display 1. Log in to the system 2. System home page 3. New pets​ 4. Modify pets 3, Partial code AdminDaoImpl PetDaoImpl pet-add.jsp pet-add-do.jsp pet-update.jsp pet-update-d ...

ArrayList overview(1) ArrayList is a variable length collection class, which is implemented based on fixed length array.(2) ArrayList allows null values and duplicate elements. When the number of elements added to ArrayList is greater than the capacity of its underlying array, it will regenerate a larger array through the capacity expansion mec ...

While the code is rolling, a message pops up in the company's chat tool: "Brother wolf, my machine always FGC frequently..." I quickly opened the dialog box and replied with a witty expression Then continue silently. Then, the little partner smashed a GC log 2019-09-17T20:33:57.889+0800: 4753520.554: [Full GC (Metadata GC Th ...

HashMap source code analysis Structure diagram of HashMap Introduction to HashMap principle Array: use a continuous storage unit to store data. For the search of the specified subscript, the time complexity is O(1); To search through a given value, you need to traverse the array and compare the given keywords and array elements one by one. ...

prefaceBigDecimal is Java A type provided in the math package that can be used for precise operations. Therefore, BigDecimal is frequently used in payment, e-commerce and other businesses. Moreover, it has many internal methods, such as addition, subtraction, multiplication, division and other operation methods, which can be called directly. In ...

How to understand progressive framework Progressive framework means that if you are developing a small application, you can use vue's core library for easy development. If you are developing a large application, you can add vue's plug-in library for development. In other words, it can be selected according to the size of the application, so as ...

summary To learn the File class in Java, first of all, we need to know that the definition of File class in Java API, that is, the abstract representation of File and directory path, is not the File itself. Therefore, in the File class, the operations involved are only about the File name and directory path, not the File content. If you wa ...

VII Arrays and data storage Learning objectives: 1. Array definition An array is an ordered collection of data of the same type. Among them, each data is called an element, and each element can access them through an index (subscript). Four basic features of arrays: The length is determined. Once an array is created, its size cannot be ch ...