Analysis of the technical principles of the Pojava Persistence framework in the Java class library

Analysis of the technical principles of the Pojava Persistence framework in the Java class library Pojava Persistence (POJP) is a persistent framework based on Java language, which aims to simplify database operations, improve application performance and maintainability.This article will explore the technical principles of POJP to help readers better understand and apply the framework. 1. Introduction to POJP Technical Principles The core idea of the POJP framework is to configure the mapping relationship between the Java object and the database table, and provide some concise APIs, so that developers can easily perform CRUD (creation, read, update, and delete) operations.The POJP framework is based on the ORM (object relationship mapping) mode. By mapping the persistent object and the database table, the automatic conversion between the object and the data is realized. 2. The main component of the POJP framework 1. Configuration file: POJP framework defines the mapping relationship between the Java object and the database table by configured files.This configuration file can be XML format or annotation method, and developers can choose the appropriate configuration method as needed. 2. Specific object (PO): Developers need to create a PO class to represent the database table, and to achieve the mapping of the object and table by defining fields and associations in the PO class. 3. Database connection management: The POJP framework provides the management function of the database connection. Developers can set the database connection information and use the API provided by the framework to obtain the database connection by configure the file. 4. Basic CRUD operation: The POJP framework provides a series of APIs, including basic CRUD operations such as inserting, querying, updating, and deleting. Developers can complete these APIs to complete the operation of the database. Third, the use of the POJP framework Below a simple example to demonstrate the use of the POJP framework. 1. Create a PO class: @Table(name = "student") public class Student { @Id @Column(name = "id") private int id; @Column(name = "name") private String name; // omit the definition of other fields and associations, getter and setter method, etc. } 2. Configuration mapping relationship: <?xml version="1.0" encoding="UTF-8"?> <mappings> <entity table="student" class="com.example.Student"> <field name="id" column="id" type="int"/> <field name="name" column="name" type="String"/> </entity> <!-omit the mapping configuration of other tables-> </mappings> 3. Perform CRUD operation: public class Main { public static void main(String[] args) { // Initialize the POJP framework PersistenceManager.initialize("pojp-config.xml"); // Get the database connection Connection connection = PersistenceManager.getConnection(); // Create a PO object Student student = new Student(); student.setId(1); Student.setname ("Zhang San"); // Insert data PersistenceManager.insert(student, connection); // Query data Student result = PersistenceManager.select(Student.class, connection, "id = ?", 1); System.out.println(result.getName()); // update data Student.setname ("Li Si"); PersistenceManager.update(student, connection); // delete data PersistenceManager.delete(student, connection); // Close the database connection PersistenceManager.closeConnection(connection); } } Through the above example code, we can see the simple and ease of use and flexibility of the POJP framework.Developers only need to define the PO class and configuration mapping relationship, so they can implement CRUD operations through the API provided by POJP, which greatly simplifies the writing of database operations. Summarize: The Pojava Persistence framework is a powerful and easy -to -use Java persistence framework. By mapping the Java object and the database table, the automatic conversion of objects and data is realized.Through the introduction of this article, readers can learn more deeply about the technical principles of the POJP framework and can be applied according to their actual needs.