mjedynak

private long counter = 0;

private final Object mutex = new Object();

public void incrementCounter() {
   synchronized (mutex) {
      counter++;
   }
}

mjedynak

public synchronized void incrementCounter() {	
   counter++;		
}

mjedynak

private AtomicLong counter = new AtomicLong();

public void incrementCounter() {
   counter.incrementAndGet();		
}

mjedynak

private Object resource = new Object();

public synchronized Object getResource() {
   return resource;
}

public synchronized void setResource(Object resource) {
   this.resource = resource;
} 

mjedynak

private Object resource = new Object();
private AtomicReference<Object> reference = new AtomicReference<Object>(resource);

public Object getResource() {
   return reference.get();
}

public void setResource(Object resource) {
   reference.set(resource);
}

mjedynak

Runnable runnable = new Runnable() {   
    @Override                          
    public void run() {                
        System.out.println("thread 1");
    }                                  
};                                     
Thread thread1 = new Thread(runnable); 
thread1.start();                       

mjedynak

Thread thread2 = new Thread() {        
    @Override                          
    public void run() {                
        System.out.println("thread 2");
    }                                  
};                                     
thread2.start();                       

mjedynak

ExecutorService executor = Executors.newSingleThreadExecutor();
Runnable runnable = new Runnable() {                           
    @Override                                                  
    public void run() {                                        
        System.out.println(Thread.currentThread().getName());                        
    }                                                          
};                                                             
executor.execute(runnable);                                    
                                                               
// executing once again                                        

mjedynak

ExecutorService executor = Executors.newFixedThreadPool(2);  
Runnable runnable = new Runnable() {                         
    @Override                                                
    public void run() {                                      
        System.out.println(Thread.currentThread().getName());
    }                                                        
};                                                           
executor.execute(runnable);                                  
executor.execute(runnable);                                  
                                                             

mjedynak

public class Resource {

    private Object veryImportantObject = new Object();

    private final Object mutex = new Object();

    public synchronized Object getVeryImportantObject() {
        System.out.println("Getting object");
        return veryImportantObject;
    }