The use of javassist, and the simple implementation of the GenerateDaoProxy mechanism in MyBatis using javassist 1. What is javassist? 2. Simply use javassist: here we only consider simple implementation classes through interfaces 3. Provide tool classes for SqlSession 4. Dynamically generate a simple Dao implementation class: 1. What is javassist? Javaassist is a class […]
Tag: javassist
JDK, CGLib, Javassist implement dynamic proxy
1. Class loading 1. Class loading process simulation (first understand the class loading process before simulating class loading during running time – create a proxy class and call the target method) public class Programmer {<!– –> public void code() {<!– –> System.out.println(“I’m a Programmer,Just Coding….”); } } /** * Customize a class loader to convert […]
javassist implements interface simulates mybatis to generate proxy classes
Tool class for dynamically creating proxy objects package com.wsd.util; import org.apache.ibatis.javassist.ClassPool; import org.apache.ibatis.javassist.CtClass; import org.apache.ibatis.javassist.CtMethod; import org.apache.ibatis.session.SqlSession; import java.lang.reflect.Constructor; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.util.Arrays; /** * Use the javassist library to dynamically generate the implementation class of the dao interface * @author: Mr. Wang * @create: 2023-07-08 18:44 **/ public class ProxyUtil { public […]
[SSM]MyBatis uses javassist to generate class and interface proxy mechanism
Directory 6. Use javassist to generate classes 6.1 Use of Javassist 6.2 Generate DaoImpl class using Javassist 7. Interface proxy mechanism and use in MyBatis 7.1 Use the interface proxy mechanism in the previous web application 7.2 Use the interface proxy mechanism to complete the previous CRUD (part of the code) 6. Use javassist to […]
Javassist dynamically generates and modifies bytecode demo
Javassist is an open source class library for analyzing, editing, and creating Java bytecodes. It is widely used in procedural class file operations and runtime AOP frameworks. It can dynamically change the structure of classes, or dynamically generate classes. About javassist and reflection Javassist is not implemented through reflection, but by directly manipulating bytecode. In […]
Javassist bytecode operation technology and actual project landing (the most complete)
Javasisst bytecode technology Javassist is a java language implementation class library for processing java bytecode Based on this technology, I actually landed a project based on javaagent-based scheduled task agent 1. Important categories 1, ClassPool -> class pool A ClassPool is a container for storing CtClass. Once a CtClass object is created, it will be […]
MyBatis| Make ?javassist? into a class, interface-oriented way for CRUD
One: make ?javassist? into a class Javassist is an open source library for analyzing, editing, and creating Java bytecode. Created by Shigeru Chiba, Department of Mathematics and Computer Science, Tokyo Graduate School of Engineering. It has augmented the open source JBoss application server project by implementing a dynamic “AOP” framework (aspect-oriented programming) for JBoss by […]
[Learn a little bit every day: bytecode enhancement] class bytecode structure, ASM generates new class bytecode, javassist operation bytecode, Instrument class library loads classes at runtime, Agent injects into JVM, JPDA interface attach
Bytecode enhancement 1. Class bytecode structure 2. ASM generates new class bytecode 3. javassist 3.1 Core Objects 3.2 Create a class 3.3 Dynamically modify a class 3.4 Modify class by instruction Fourth, the Instrument library dynamically modifies the class 5. Agent injection into Instrument 5.1 – agentlib way 5.2 Inject at runtime in the form […]
Use Javassist to dynamically generate classes, and Arthas to view the content of dynamic proxy generation classes
java reflection Disadvantages of reflection: Performance overhead: Because reflection involves dynamically resolving types, certain JVM optimizations cannot be performed (because it can’t really understand what you’re doing) strong>. Therefore, the performance of reflective operations is slower than that of non-reflective operations, and you should avoid frequently called code sections in performance-sensitive applications. Javassist It is […]
Realize the implementation class function of MyBatis dynamically generating DAO through javassist operation bytecode
Article directory illustrate Notice Prepare MyBatisGenerateDaoProxyTool mock test Code reference: Description In practice, the principle of mybatis operating data addition, deletion, modification and query through the interface is realized through javassist. In the MyBatis framework, we can directly operate through the Dao interface and XML, and there is no specific implementation class, so what is […]