Collection synchronized
In this chapter you will learn:
Get a synchronized collection
A synchronized collection is good for multithread application. By using synchronized collections we can coordinate the usage of a collection among different applications.
We can make a collection to be synchronized using the following methods.
static<T> Collection<T> synchronizedCollection(Collection<T> c)static<T> List<T> synchronizedList(List<T> list)static<K,V> Map<K,V> synchronizedMap(Map<K,V> m)static<T> Set<T> synchronizedSet(Set<T> s)static<K,V> SortedMap<K,V> synchronizedSortedMap(SortedMap<K,V> m)static<T> SortedSet<T> synchronizedSortedSet(SortedSet<T> s)
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/* java2 s . c o m*/
public class Main {
public static void main(String[] args) {
Collection<String> c = Collections.synchronizedCollection(new ArrayList<String>());
List<String> list = Collections.synchronizedList(new ArrayList<String>());
Set<String> s = Collections.synchronizedSet(new HashSet<String>());
Map<String,String> m = Collections.synchronizedMap(new HashMap<String,String>());
}
}
Create a synchronized Map
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
//from jav a2 s .c o m
public class MainClass {
public static void main(String args[]) {
Set simpsons = new HashSet();
simpsons.add("B");
simpsons.add("H");
simpsons.add("L");
simpsons = Collections.synchronizedSet(simpsons);
synchronized (simpsons) {
Iterator iter = simpsons.iterator();
while (iter.hasNext()) {
System.out.println(iter.next());
}
}
Map map = Collections.synchronizedMap(new HashMap(89));
Set set = map.entrySet();
synchronized (map) {
Iterator iter = set.iterator();
while (iter.hasNext()) {
System.out.println(iter.next());
}
}
}
}
The output:
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What you will learn in the next chapter: