Programmer Help

Last time I wrote about JPA, let's talk about Spring Data JPA Spring Data JPA is a set of JPA application framework encapsulated by spring based on ORM framework and JPA specification. Developers can use very simple code to access and operate the database. In daily use, Spring Data JPA development frees us from the operation of Dao layer, and ...

Parallel and Concurrent Parallel: Multiple CPU instances or machines executing a piece of processing logic at the same time are truly simultaneous. Concurrency: A CPU or a machine, through the CPU scheduling algorithm, makes the user appear to be executing at the same time, actually not at the same time from the CPU operation level. Conc ...

Next, let's analyze the processing of connection resources by transaction operations, that is, the management of resources (resources attribute) by transaction synchronization manager in transaction processing. 2. Spring transaction processing The TransactionSynchronizationManager#bindResource binding connects resources to the resources attri ...

1, One to many configuration and lazy loading query 1. One to many 1.1 association refers to the reference relationship between classes. If class A is associated with class B, the referenced class B will be defined as an attribute of class A. 1.2. One to many association: For example: orders and order items. An order has multiple order items ...

1, One to many configuration and lazy loading query 1. One to many 1.1 association refers to the reference relationship between classes. If class A is associated with class B, the referenced class B will be defined as an attribute of class A. 1.2. One to many association: For example: orders and order items. An order has multiple order ite ...

1, Data type Basic type byte - 8short - 16char - 16int - 32float- 32long - 64double - 64boolean ~~ boolean has only two values: true and false. It can be stored in 1 bit, but the specific size is not specified. The JVM will convert boolean data to int at compile time, using 1 to indicate true and 0 to indicate false. The JVM supports bool ...

Environmental description Declarative transaction (XML(tx namespace management transaction)) tx configuration tx:advice Name: tx:advice Type: Label Attribution: beans tag Role: dedicated to declaring transaction notifications Format: <beans> <tx: advice id ="txAdvice" transaction-manager="txManager"> </tx:advice> &l ...

This page will introduce examples of Spring Boot Security REST + JPA + Hibernate + MySQL CRUD. When we use Spring Boot to create an application, we only need to write a few lines of code to include functions such as network request, security authentication and database connection. If Spring Boot obtains Spring Security in the classpath, i ...

Custom validation Hibernate Validate provides rich built-in validation annotations. When these do not meet your requirements, we can customize the validation annotations. For example, we customize a keyword filtering validation rule, and the annotation is as follows. 1. Write validation rule annotation class package com.yyoo.springmvc.valid; ...

I. MyBatis Loading Policy 1. What is delayed loading? Problem: Configuration and implementation of one-to-one, one-to-many, many-to-many relationships in Mybatis is achievable Object's associated query. Many times in the actual development process we don't always need to load user information before we have to load his order information. This ...