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Processes and threads A process (. exe) contains multiple threads, which occupy the resources of process memory Why? It's like QQ can type and chat with others while video There is a picture and a truth example Write a Java The program implements multithreading. The name of the thread is output in the thread. It is output once in 1000 ...

Request forwarding and redirection for spring MVC 1. Request forwarding of spring MVC -- thymeleafView thymeleafVIew view If the return value [view name] of the method processing the request is not prefixed, this view will be parsed by the view parser configured by spring MVC. This view is a thymeleaf view. As for why there is such a distinc ...

First, you need to create an order table Create the database migration file when creating the model php artisan make:model Order -m Perfect database fields public function up() { Schema::create('orders', function (Blueprint $table) { $table->id(); $table->integer('user_id')->comment('User placin ...

summary Singleton mode: in the whole system, only one instance object of a class can be obtained and used Key points: Private constructorCreate object inside classProvide static methods for obtaining instances externally Hungry Han style Common way Hungry Chinese style: when the class is loaded, create the object directly, which is thread ...

Development environment: Development environment: Python 3 Tools: pandas, matplotlib.pyplot Data source: Data address: data set Data Description: a total of 28010 pieces of data occurred in one month were collected in this data set, Include the following: ['order number', 'total amount', 'buyer's actual payment amount', 'receiving address' ...

scene Three commonly used auxiliary classes are provided in JUC. These auxiliary classes can well solve the frequent operation of Lock lock when there are too many threads. The three auxiliary classes are: • CountDownLatch: decrease count • CyclicBarrier: Circular barrier • Semaphore: signal light Decrease count CountDownLatch ...

Today, let's talk about structure Why structure Because in practical problems, a group of data often has many different data types. For example, to register student information, you may need to use char type name, int type or char type student number, int type age, char type gender, and float type grade. For another example, for recording ...

Data management of MySQL 1.DML language (very important) The meaning of database: data storage and data management DML: Data Manipulation Language insertupdatedelete 2. Foreign keys Method 1: add constraints to the primary key when creating a table (more complex) CREATE TABLE `grade`( `gradeid` INT(10) NOT NULL AUTO_INCREMENT CO ...

sort The concept and application of sorting Sorting concept ==Sorting: = = the so-called sorting is the operation of arranging a string of records incrementally or decrementally according to the size of one or some keywords. ==Stability: = = if there are multiple records with the same keyword in the record sequence to be sorted, th ...

1. Introduction to spring event monitoring The Spring framework provides a set of event publishing and listening mechanism. For developers, they can publish events as long as they hold the ApplicationContext instance, and they can receive and process events as long as they implement the ApplicationListener interface. A typical use example ...