Get class files and attributes by reflection

The following code is to be obtained by using the reflection mechanism ：

package com.zzuli;

/** * @author luoqingchen * @reate 2022-02-03-9:46 */
public class reflect01 {
    
    private boolean flag;
    public  int a;
    protected  String s;
}

Reflection acquisition ：

public class Test01 {
    
    public static void main(String[] args) throws Exception {
    
      Class reflect=Class.forName("com.zzuli.reflect01");
        StringBuilder s=new StringBuilder();
        s.append(Modifier.toString(reflect.getModifiers())+" class "+reflect.getSimpleName());
        s.append("\n");
        s.append("{");
        s.append("\n");
       Field[] fields= reflect.getDeclaredFields();
       for (Field fs:fields){
    
           s.append("\t\t");
          s.append( Modifier.toString(fs.getModifiers()));
          s.append(" ");
          s.append(fs.getType().getSimpleName());
          s.append(" ");
          s.append(fs.getName());
          s.append("\n");

       }
        s.append("\n");
        s.append("}");
        System.out.println(s);
    }
}

Running results ：

Use reflection to get the attribute value in the class ：

public class Test02 {
    

    public static void main(String[] args)  throws  Exception{
    
        Class reflect=Class.forName("com.zzuli.reflect01");
        Object obj=reflect.newInstance();
        // get attribute 
        Field field=reflect.getDeclaredField("a");
            // Setting property values 
        field.set(obj,8);
       Object obj2=field.get(obj);
        // Get the attribute value 
        System.out.println(obj2);
    }
}

Running results ：（ This example is getting public The value of the property ）

Want to get the value of the private attribute , Need to break the package ：

public class Test02 {
    

    public static void main(String[] args)  throws  Exception{
    
        Class reflect=Class.forName("com.zzuli.reflect01");
        Object obj=reflect.newInstance();
        // get attribute 
        Field field=reflect.getDeclaredField("flag");
        // Break the package 
        field.setAccessible(true);
            // Setting property values 
        field.set(obj,true);
       Object obj2=field.get(obj);
        // Get the attribute value 
        System.out.println(obj2);
    }
}

Running results ：