JAVA: Implementing caching in JAVA using weakHashMap() in ORM framework.

If there are static queries  and once you hit the database , next time you dont need to hit the DB again , whereas you store it (caching) and get the values back

I have implemented this using three classes - class1,class2 and class3

class3 invoking the class1 object 

public class class3 {

  public static void main(String args[]) throws InterruptedException{
     class1 obj1= new class1();
     Thread t1 = new Thread(obj1,"Thread1");
     t1.start();
     t1.join();
     Thread t2 = new Thread(obj1,"Thread2");
     t2.start();
  }

}

class 2 has many variables which are mapped to database

public class class2 {

 int x;

/*

many variables mapped to database

*/

}

class1 implements cache. class 1 stores the object of the class2 and next time it will not hit the database ,it will get the object from the map and calls the variables

import java.util.*;

import org.apache.naming.java.javaURLContextFactory;

public class class1 implements Runnable {

 int i;
 Map map = new WeakHashMap();
 class2 obj = new class2();

 public  void run(){
  if(i==0){
  // database connection code;
  obj.x=10;// assign the field values to the class2 obj
  map.put(obj.getClass(), obj); // save the object in the hashMap
  System.out.println(Thread.currentThread().getName()+" "+obj.x);
  i++;  //increment the integer.
  }
  else{
  class2 x =(class2)map.get(obj.getClass());
  System.out.println("i am in else part");
  System.out.println(Thread.currentThread().getName()+" "+x.x);

 }
}
}