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Thread: cannot find symbol Error

  1. #1
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    Default cannot find symbol Error

    Can someone help me with debugging this error?
    This is the error Im getting but I do not know why.

    SharedBufferTest.java:16: cannot find symbol
    symbol : constructor Producer(Buffer)
    location: class Producer
    Producer producer = new Producer( sharedLocation );
    ^
    SharedBufferTest.java:17: cannot find symbol
    symbol : constructor Consumer(Buffer)
    location: class Consumer
    Consumer consumer = new Consumer( sharedLocation );

    Here is the code for SharedBufferTest.java
    public class SharedBufferTest {
    	public static void main( String [] args)
    	{
     
    	Buffer sharedLocation = new UnsynchronizedBuffer();
     
     
    	Producer producer = new Producer( sharedLocation );
    	Consumer consumer = new Consumer( sharedLocation );
    	Semaphore valueProduced=new Semaphore(0);
    	Semaphore valueConsumed = new Semaphore(1);
     
    		producer.start();
    		consumer.start();
     
    	}
    }

    Here is the Producer code
    public class Producer extends Thread{
    	private Buffer sharedLocation;
    	private Semaphore valueProduced;
    	private Semaphore valueConsumed;
     
    	public Producer (Buffer shared, Semaphore valueP, Semaphore valueC) {
    		super("Producer");
    		sharedLocation = shared;
    		valueProduced = valueP;
    		valueConsumed = valueC;
    	}
     
    	public void run() {
    		for (int count = 1; count <= 4; count++){
    			//try {
    				//Thread.sleep((int) (Math.random() * 3001));
    				valueConsumed.P();
    				//check to see if the value has been consumed P( valueConsumed );
    				sharedLocation.set(count);
    				//let consumer thread know it can consume the value
    				valueProduced.V();
    			//}
    			//catch (InterruptedException exception) {
    				//exception.printStackTrace();
    			//}
    		}
    		System.err.println(getName() + " done producing.");
    	}
    }

    Here is the Consumer code
    public class Consumer extends Thread{
    	private Buffer sharedLocation;
    	private Semaphore valueProduced;
    	private Semaphore valueConsumed;
     
    	public Consumer (Buffer shared, Semaphore valueP, Semaphore valueC) {
    		super("Consumer");
    		sharedLocation = shared;
    		valueProduced = valueP;
    		valueConsumed = valueC;
     
    	}
    	public void run() {
    		int sum = 0;
    		for (int count=1; count<=4; count++) {
    			//try{
    				//how it shouldve worked:
    				//sharedLocation.get()=null; check to see if the buffer is empty
    				//if 
    				//Thread.sleep((int) (Math.random() * 3001));
    				valueProduced.P();
    				sum += sharedLocation.get();
    				valueConsumed.V();
    			//}
    			//catch (InterruptedException exception) {
    				//exception.printStackTrace();
    			//}
    		}
    		System.err.println(getName() + " done consuming. and sum= " + sum);
    	}
    }
    Last edited by bananasplitkids; March 8th, 2010 at 10:54 AM. Reason: left out code


  2. #2
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    Default Re: cannot find symbol Error

    So I recompiled the program again and now Im getting these errors:

    cannot find symbol
    symbol : class Buffer
    location: class SharedBufferTest
    Buffer sharedLocation = new UnsynchronizedBuffer();
    ^
    ./UnsynchronizedBuffer.java:9: cannot find symbol
    symbol: class Buffer
    public class UnsynchronizedBuffer implements Buffer {
    ^
    ./Producer.java:10: cannot find symbol
    symbol : class Buffer
    location: class Producer
    private Buffer sharedLocation;
    ^
    ./Producer.java:14: cannot find symbol
    symbol : class Buffer
    location: class Producer
    public Producer (Buffer shared, Semaphore valueP, Semaphore valueC) {
    ^
    SharedBufferTest.java:16: internal error; cannot instantiate Producer.<init> at Producer to ()
    Producer producer = new Producer( sharedLocation );
    ^
    ./Consumer.java:10: cannot find symbol
    symbol : class Buffer
    location: class Consumer
    private Buffer sharedLocation;
    ^
    ./Consumer.java:14: cannot find symbol
    symbol : class Buffer
    location: class Consumer
    public Consumer (Buffer shared, Semaphore valueP, Semaphore valueC) {
    ^
    SharedBufferTest.java:17: internal error; cannot instantiate Consumer.<init> at Consumer to ()
    Consumer consumer = new Consumer( sharedLocation );
    ^
    ./Consumer.java:30: inconvertible types
    found : <nulltype>
    required: int
    sum += sharedLocation.get();

  3. #3
    Member Darryl.Burke's Avatar
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    Default Re: cannot find symbol Error

    Double posted and answered on the Oracle forums.
    New To Java - cannot find symbol

    db

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