Java – how to set a value to a class variable without using a setter

I want to insert a value into the object variable without using a setter How is that possible?

This is an example

Class X{
String variableName;
// getters and setters
}

Now I have a function, which contains the variable name, the value to be set and the object of class X

I tried to use a generic method to set the value to object (objectofclass) and pass the value I (valuetobeset) in the corresponding variable (variablename)

Object functionName(String variableName,Object valueToBeSet,Object objectOfClass){

    //I want to do the exact same thing as it does when setting the value using the below statement
    //objectOfClass.setX(valueToBeSet);

return objectOfClass;
}

Solution

This code has not been tested You can try this

Class to import

import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

method

public Object functionName(String variableName,Object objectOfClass) throws IntrospectionException,NoSuchMethodException,SecurityException,illegalaccessexception,IllegalArgumentException,InvocationTargetException{

        //I want to do the exact same thing as it does when setting the value using the below statement
        //objectOfClass.setX(valueToBeSet);
        Class clazz = objectOfClass.getClass();
        BeanInfo beanInfo = Introspector.getBeanInfo(clazz,Object.class); // get bean info
        PropertyDescriptor[] props = beanInfo.getPropertyDescriptors(); // gets all info about all properties of the class.
        for (PropertyDescriptor descriptor : props) {
            String property = descriptor.getDisplayName();
            if(property.equals(variableName)) {
                String setter = descriptor.getWriteMethod().getName();
                Class parameterType = descriptor.getPropertyType();
                Method setterMethod = clazz.getDeclaredMethod(setter,parameterType); //Using Method Reflection
                setterMethod.invoke(objectOfClass,valueToBeSet);
            }

        }

    return objectOfClass;
    }