Reflection: Set value to an object property

Following method set an object property using reflection.

public static boolean set(Object object, String fieldName, Object fieldValue) {
 Class<?> clazz = object.getClass();
 while (clazz != null) {
  try {
   Field field = clazz.getDeclaredField(fieldName);
   field.setAccessible(true);
   field.set(object, fieldValue);
   return true;
  } catch (Exception e) {
   throw new IllegalStateException(e);
  }
 }
 return false;
}

Find the below working application.

Employee.java

package com.sample.app.model;

public class Employee {
 private int id;
 private String name;

 public int getId() {
  return id;
 }

 public void setId(int id) {
  this.id = id;
 }

 public String getName() {
  return name;
 }

 public void setName(String name) {
  this.name = name;
 }

}

MainApp.java

package com.sample.app;

import java.lang.reflect.Field;

import com.sample.app.model.Employee;

public class MainApp {
 public static boolean set(Object object, String fieldName, Object fieldValue) {
  Class<?> clazz = object.getClass();
  while (clazz != null) {
   try {
    Field field = clazz.getDeclaredField(fieldName);
    field.setAccessible(true);
    field.set(object, fieldValue);
    return true;
   } catch (Exception e) {
    throw new IllegalStateException(e);
   }
  }
  return false;
 }

 @SuppressWarnings("unchecked")
 public static <V> V get(Object object, String fieldName) {
  Class<?> clazz = object.getClass();
  while (clazz != null) {
   try {
    Field field = clazz.getDeclaredField(fieldName);
    field.setAccessible(true);
    return (V) field.get(object);
   } catch (Exception e) {
    throw new IllegalStateException(e);
   }
  }
  return null;
 }

 public static void main(String args[]) throws InstantiationException, IllegalAccessException {
  Object object = Employee.class.newInstance();
  
  set(object, "id", 123);
  set(object, "name", "Krishna");
  
  System.out.println("id : " + get(object, "id"));
  System.out.println("name : " + get(object, "name"));
 }
}

Run MainApp.java, you will see below messages in console.

id : 123

name : Krishna

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