How do I fix these errors? Java

import android.app.Activity;
import java.util.Scanner;
import java.lang.Boolean;

protected class purchase {

private void int validate=invokemeta_BillingManager,invoke_selforderId,invoke_selflinkedPurchasedToken;

		boolean isvalidated;

			void bool(){

				invokevalidate(false);

				exit();
			}

		private void invokevalidate(boolean b) {
			
		}
	}

error: <identifier> expected

private void int
validate=invokemeta_BillingManager,invoke_selforderId,invoke_selflinkedPurchasedToken;
            ^
error: '(' expected

private void int validate=invokemeta_BillingManager,invoke_selforderId,invoke_selflinkedPurchasedToken;
             ^
error: <identifier> expected

private void int validate=invokemeta_BillingManager,invoke_selforderId,invoke_selflinkedPurchasedToken;
                         ^
3 errors