Java

The constructor Writer(ReadWriteLock) is undefined
The constructor Reader(ReadWriteLock) is undefined

• define constructors accepting as single readerwriterlock object as argument;
• change your actual constructor calls and add the integer argument which you seem to have forgotten.

public class ReaderWriter{
		   public static final int NUM_OF_READERS = 3;
		   public static final int NUM_OF_WRITERS = 2;

		    public static void main(String args[]){
		 	   ReadWriteLock rwlock = new ReadWriteLock();
		   
		      Thread[] readerArray = new Thread[NUM_OF_READERS];
		      Thread[] writerArray = new Thread[NUM_OF_WRITERS];
		   
		      for (int i = 0; i < NUM_OF_READERS; i++) {
		         readerArray[i] = new Thread(new Reader(rwlock));
		         readerArray[i].start();
		      }
		   
		      for (int i = 0; i < NUM_OF_WRITERS; i++) {
		         writerArray[i] = new Thread(new Writer(rwlock));
		         writerArray[i].start();
		      }
		   }

class Reader implements Runnable
{

	private static int readers = 0;
   private ReadWriteLock rwlock;
   private int readerNum;

    public Reader(ReadWriteLock rwlock) {
      this.rwlock = rwlock;
      this.readerNum=Reader.readers++;
   }

	public void run() {
      while (true) {
    	  final int DELAY = 5000;
          try
          {
            Thread.sleep((int) (Math.random() * DELAY));
          }
          catch (InterruptedException e) { 
          }
         System.out.println("reader " + readerNum + " wants to read.");
         rwlock.ReadLock(readerNum);
      // you have access to read from the database
      // let's read for awhile .....
         try
         {
           Thread.sleep((int) (Math.random() * DELAY));
         }
         catch (InterruptedException e) {
         }
         rwlock.ReadUnLock(readerNum);
      }
   };
}

pembepanter wrote:

But in that way still it is not working.

pembepanter wrote:

So I had an error

Member 14677234 wrote:

Please let me know your opinions and suggestions.