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plusNanos(int offset): increases the specified nanosecond Reduce related methods minusYears(int offset): decrease the specified year minusMonths(int offset): decrease the specified month minusWeeks(int offset): decreases the specified week minusDates(int offset): decrease the specified date minusHours(int offset): decrease the specified ...

Definition: exceptions in Exception except RuntimeException and its subclasses. Features: the Java compiler will check it. If such an exception occurs in the program, For example, ClassNotFoundException (the specified class exception is not found) and IOException (IO stream exception), either declare and throw it through throws or catch it thr ...

1, Foreword You should have seen in the circle of friends that a picture is displayed in the form of nine squares. The effect is roughly as follows: To achieve the above effect is very simple, we only need to intercept nine areas of the image. Today we will take you to use Python to realize the generation of Jiugong grid pictures. Before st ...

catalogue preface Cache pool (constant pool) 1. Prove the existence of cache pool 2. Cache value range Implicit type conversion keyword final static 1. Static variable 2. Static inner class this,super Access modifier java8 features abnormal Java collection (container) 1,List, Set, Queue, Map preface This series focuses on t ...

  Introduction: today I will bring you an e-commerce data analysis case. I sorted it out and shared it with you in the form of notes. The background of the case is that the overall sales of an e-commerce have been rising for several consecutive years, but the growth rate has slowed down in recent years. It is necessary to find effe ...

prefaceOkHttp can be said to be the most common network request framework in Android development. OkHttp is easy to use, extensible and powerful. OkHttp source code and principle are also frequent visitors in the interview However, OKHttp has a lot of source code content. If you want to learn its source code, you are often confused and can't g ...

*/ public HashMap(int initialCapacity, float loadFactor) { if (initialCapacity < 0) throw new IllegalArgumentException("Illegal initial capacity: " + initialCapacity); if (initialCapacity > MAXIMUM_CAPACITY) initialCapacity = MAXIMUM_CAPACITY; if (loadFactor <= 0 || Float.isNaN(load ...

/** * Send get request; With request parameters * * @param url Request address * @param params Request parameter set * @return * @throws Exception */ public static HttpClientResult doGet(String url, Map<String, String> params) throws Exception { return doGet(url, null, params); } /** * Send get request; With reques ...

Chapter 1 Introduction to SQL1.1. What is sqlSQL: Structure Query Language. (Structured Query Language), operate the database through SQL (operation database, operation table, operation data)SQL was determined as the American Standard of relational database language by American National Bureau of standards (ANSI), and later adopted as the inte ...

#User table create table user( id int auto_increment primary key, username nvarchar(20) null, password nvarchar(20) null, name nvarchar(20) null, gender nchar(10) null, age int null, address nvarchar(20) null, phone nvarchar(11) unique null, email nvarchar(30) null ); #Student list create table student( id int auto_increment prim ...