Java.lang.instrument.ClassDefinition Java的类

此类用于将提供的类和类文件字节绑定到单个 ClassDefinition 对象中。这些类提供了提取有关类类型和类文件字节信息的方法。这个类是Java.lang.Object 类的子类。

类声明：

public final class ClassDefinition
extends Object

构造函数：

Constructor	Description
ClassDefinition(Class theClass, byte[] theClassFile)	This constructor creates a new instance of ClassDefinition class by binding the supplied class and class file bytes.

方法：

Method	Description
getDefinitionClass()	This method is used to get the class type of this class
getDefinitionClassFile()	This method Is used to get the array of bytes that contains the new class file.

示例 1： Java程序创建新的 ClassDefinition 对象

Java

// Java program to create new ClassDefinition object
import java.lang.instrument.ClassDefinition;
  
// driver class
public class GFG {
    // demoClass
    static class demoClass {
        void msg() { System.out.println("GeeksForGeeks"); }
    }
    // main method
    public static void main(String[] args)
    {
        try {
  
            // creating demoClass object
            demoClass cls = new demoClass();
            
            // creating object of supplied class
            Class theClass = cls.getClass();
            
            // creating array of class files
            byte[] classFiles = { 0 };
            
            // creating a new ClassDefinition object
            ClassDefinition classdefinition
                = new ClassDefinition(theClass, classFiles);
            System.out.println(
                "ClassDefinition object successfully created");
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Java

// Java program to illustrate ClassDefinition class methods
import java.lang.instrument.ClassDefinition;
  
// driver class
public class GFG {
    
    // demoClass
    static class demoClass {
        void msg() { System.out.println("GeeksForGeeks"); }
    }
    
    // main method
    public static void main(String[] args)
    {
        try {
  
            // creating demoClass object
            demoClass cls = new demoClass();
            
            // creating object of supplied class
            Class theClass = cls.getClass();
            
            // creating array of class files
            byte[] classFiles = { 0 };
            
            // creating a new ClassDefinition object
            ClassDefinition classdefinition
                = new ClassDefinition(theClass, classFiles);
            
            // printing the class
            System.out.println(
                classdefinition.getDefinitionClass());
            
            // printing array of bytes that contain class
            // files
            System.out.println(
                classdefinition.getDefinitionClassFile());
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
}

输出

ClassDefinition object successfully created

示例 2： Java程序来说明 ClassDefinition 类方法

Java

// Java program to illustrate ClassDefinition class methods
import java.lang.instrument.ClassDefinition;
  
// driver class
public class GFG {
    
    // demoClass
    static class demoClass {
        void msg() { System.out.println("GeeksForGeeks"); }
    }
    
    // main method
    public static void main(String[] args)
    {
        try {
  
            // creating demoClass object
            demoClass cls = new demoClass();
            
            // creating object of supplied class
            Class theClass = cls.getClass();
            
            // creating array of class files
            byte[] classFiles = { 0 };
            
            // creating a new ClassDefinition object
            ClassDefinition classdefinition
                = new ClassDefinition(theClass, classFiles);
            
            // printing the class
            System.out.println(
                classdefinition.getDefinitionClass());
            
            // printing array of bytes that contain class
            // files
            System.out.println(
                classdefinition.getDefinitionClassFile());
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
}

输出

class GFG$demoClass
[B@448139f0