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Java Collections - Collections.synchronizedNavigableSet() Examples

Java Collections Java Java API 


Class:

java.util.Collections

java.lang.Objectjava.lang.Objectjava.util.Collectionsjava.util.CollectionsLogicBig

Method:

public static <T> NavigableSet<T> synchronizedNavigableSet(NavigableSet<T> s)

Returns a synchronized (thread-safe) NavigableSet backed by the specified NavigableSet.


Examples


Without synchronization:

package com.logicbig.example.collections;

import java.util.NavigableSet;
import java.util.TreeSet;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

public class SynchronizedNavigableSetExample {
private static AtomicInteger atomicInteger = new AtomicInteger(0);

public static void main(String... args) throws InterruptedException {
NavigableSet<Integer> theSet = new TreeSet<>();

final ExecutorService e = Executors.newFixedThreadPool(1000);
for (int i = 1; i <= 1000; i++) {

e.execute(() -> {
int n = atomicInteger.incrementAndGet();
try {
theSet.add(n);
} catch (Exception e1) {
//may throw exceptions when not synchronized
System.out.println(e1 + " " + n);
}
});
}

e.shutdown();
e.awaitTermination(1000, TimeUnit.SECONDS);
System.out.println(theSet.size());//should be 1000
}
}

Output

999




Using Collections.synchronizedNavigableSet:

package com.logicbig.example.collections;

import java.util.Collections;
import java.util.NavigableSet;
import java.util.TreeSet;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

public class SynchronizedNavigableSetExample2 {

private static AtomicInteger atomicInteger = new AtomicInteger(0);

public static void main(String... args) throws InterruptedException {
NavigableSet<Integer> s = new TreeSet<>();
NavigableSet<Integer> theSet = Collections.synchronizedNavigableSet(s);

final ExecutorService e = Executors.newFixedThreadPool(1000);
for (int i = 1; i <= 1000; i++) {
e.execute(() -> {
int n = atomicInteger.incrementAndGet();
try {
theSet.add(n);
} catch (Exception e1) {
//may throw exceptions when not synchronized
System.out.println(e1 + " " + n);
}
});
}
e.shutdown();
e.awaitTermination(1000, TimeUnit.SECONDS);
System.out.println(theSet.size());//should be 1000
}
}

Output

1000




See Also