The application and principle of Code Generator Core framework in the Java class library

The application and principle of Code Generator Core framework in the Java class library The Code Generator Core framework is a code generating tool widely used in the Java class library.It provides a simple and fast way to generate a large number of repetitive code, which can greatly improve development efficiency and code quality.This article will introduce the application scenarios and principles of the Code Generator Core framework, with some Java code examples. Application scenario: 1. The generation of database entities and DAO layers: The Code Generator Core framework can generate the corresponding Java entity class and DAO layer code according to the database table structure.Developers only need to specify the database connection information and table names in the configuration file, and the framework will automatically generate code. For example, we can generate a simple user physical class and DAO layer interface through the following configuration files: <generator> <database> <name>jdbc:mysql://localhost:3306/test</name> <user>root</user> <password>123456</password> </database> <table> <name>user</name> </table> </generator> 2. The generation of RESTFUL API: The Code Generator Core framework can generate the interface and implementation code of the RESTFUL API through a simple configuration file.Developers only need to define the API path, request method, and parameter information, and the framework can automatically generate the corresponding code. For example, we can generate a simple user management API through the following configuration file: <generator> <api> <path>/users</path> <method>GET</method> <parameter>UserId</parameter> </api> </generator> Original analysis: The principle of Code Generator Core framework is relatively simple, mainly divided into three steps: parsing configuration files, code generation, and writing files. 1. Analyze the configuration file: The framework first reads the information in the configuration file, and determines the method and content of the code generating according to the configuration information. 2. Code generation: According to the configuration information obtained by parsing, the framework will use the reflex mechanism of Java to dynamically generate the corresponding class and methods.For example, when generating a database entity class, the framework will dynamically generate the Java class attributes according to the table structure field, and provide the corresponding get and set methods. 3. Written file: The generated code will be written into the specified file.Developers can customize the directory and file name of generating code as needed. Java code example: The following is a simple example, showing how to use the Code Generator Core framework to generate a database physical class: public class User { private String id; private String name; private int age; // getters and setters } public class UserDAO { public User findById(String id) { // Find the records in the database and return to the User object } public void save(User user) { // Save the user object to the database } // Other database operation methods ... } When generating code, the Code Generator Core framework automatically creates a physical class and DAO layer code similar to the above example code according to the database table structure. Summarize: The Code Generator Core framework is a widely used code generation tool in the Java class library. It can help developers quickly generate a large number of repetitive code and improve development efficiency and code quality.Through simple configuration files, developers can easily generate code such as database entity class and DAO layers, RESTFUL API.