package com.journaldev.util; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; public class ConcurrentHashMapExample { public static void main(String[] args) { //ConcurrentHashMap Map<String,String> myMap = new ConcurrentHashMap<String,String>(); myMap.put("1", "1"); myMap.put("2", "1"); myMap.put("3", "1"); myMap.put("4", "1"); myMap.put("5", "1"); myMap.put("6", "1"); System.out.println("ConcurrentHashMap before iterator: "+myMap); Iterator<String> it = myMap.keySet().iterator(); while(it.hasNext()){ String key = it.next(); if(key.equals("3")) myMap.put(key+"new", "new3"); } System.out.println("ConcurrentHashMap after iterator: "+myMap); //HashMap myMap = new HashMap<String,String>(); myMap.put("1", "1"); myMap.put("2", "1"); myMap.put("3", "1"); myMap.put("4", "1"); myMap.put("5", "1"); myMap.put("6", "1"); System.out.println("HashMap before iterator: "+myMap); Iterator<String> it1 = myMap.keySet().iterator(); while(it1.hasNext()){ String key = it1.next(); if(key.equals("3")) myMap.put(key+"new", "new3"); } System.out.println("HashMap after iterator: "+myMap); } }
package com.journaldev.util;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
public class ConcurrentHashMapExample {
public static void main(String[] args) {
//ConcurrentHashMap
Map<String,String> myMap = new ConcurrentHashMap<String,String>();
myMap.put("1", "1");
myMap.put("2", "1");
myMap.put("3", "1");
myMap.put("4", "1");
myMap.put("5", "1");
myMap.put("6", "1");
System.out.println("ConcurrentHashMap before iterator: "+myMap);
Iterator<String> it = myMap.keySet().iterator();
while(it.hasNext()){
String key = it.next();
if(key.equals("3")) myMap.put(key+"new", "new3");
}
System.out.println("ConcurrentHashMap after iterator: "+myMap);
//HashMap
myMap = new HashMap<String,String>();
myMap.put("1", "1");
myMap.put("2", "1");
myMap.put("3", "1");
myMap.put("4", "1");
myMap.put("5", "1");
myMap.put("6", "1");
System.out.println("HashMap before iterator: "+myMap);
Iterator<String> it1 = myMap.keySet().iterator();
while(it1.hasNext()){
String key = it1.next();
if(key.equals("3")) myMap.put(key+"new", "new3");
}
System.out.println("HashMap after iterator: "+myMap);
}
}
package com.journaldev.util;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
public class ConcurrentHashMapExample {
public static void main(String[] args) {
//ConcurrentHashMap
Map<String,String> myMap = new ConcurrentHashMap<String,String>();
myMap.put("1", "1");
myMap.put("2", "1");
myMap.put("3", "1");
myMap.put("4", "1");
myMap.put("5", "1");
myMap.put("6", "1");
System.out.println("ConcurrentHashMap before iterator: "+myMap);
Iterator<String> it = myMap.keySet().iterator();
while(it.hasNext()){
String key = it.next();
if(key.equals("3")) myMap.put(key+"new", "new3");
}
System.out.println("ConcurrentHashMap after iterator: "+myMap);
//HashMap
myMap = new HashMap<String,String>();
myMap.put("1", "1");
myMap.put("2", "1");
myMap.put("3", "1");
myMap.put("4", "1");
myMap.put("5", "1");
myMap.put("6", "1");
System.out.println("HashMap before iterator: "+myMap);
Iterator<String> it1 = myMap.keySet().iterator();
while(it1.hasNext()){
String key = it1.next();
if(key.equals("3")) myMap.put(key+"new", "new3");
}
System.out.println("HashMap after iterator: "+myMap);
}
}
package com.journaldev.util;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
public class ConcurrentHashMapExample {
public static void main(String[] args) {
//ConcurrentHashMap
Map<String,String> myMap = new ConcurrentHashMap<String,String>();
myMap.put("1", "1");
myMap.put("2", "1");
myMap.put("3", "1");
myMap.put("4", "1");
myMap.put("5", "1");
myMap.put("6", "1");
System.out.println("ConcurrentHashMap before iterator: "+myMap);
Iterator<String> it = myMap.keySet().iterator();
while(it.hasNext()){
String key = it.next();
if(key.equals("3")) myMap.put(key+"new", "new3");
}
System.out.println("ConcurrentHashMap after iterator: "+myMap);
//HashMap
myMap = new HashMap<String,String>();
myMap.put("1", "1");
myMap.put("2", "1");
myMap.put("3", "1");
myMap.put("4", "1");
myMap.put("5", "1");
myMap.put("6", "1");
System.out.println("HashMap before iterator: "+myMap);
Iterator<String> it1 = myMap.keySet().iterator();
while(it1.hasNext()){
String key = it1.next();
if(key.equals("3")) myMap.put(key+"new", "new3");
}
System.out.println("HashMap after iterator: "+myMap);
}
}
package com.journaldev.util;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
public class ConcurrentHashMapExample {
public static void main(String[] args) {
//ConcurrentHashMap
Map<String,String> myMap = new ConcurrentHashMap<String,String>();
myMap.put("1", "1");
myMap.put("2", "1");
myMap.put("3", "1");
myMap.put("4", "1");
myMap.put("5", "1");
myMap.put("6", "1");
System.out.println("ConcurrentHashMap before iterator: "+myMap);
Iterator<String> it = myMap.keySet().iterator();
while(it.hasNext()){
String key = it.next();
if(key.equals("3")) myMap.put(key+"new", "new3");
}
System.out.println("ConcurrentHashMap after iterator: "+myMap);
//HashMap
myMap = new HashMap<String,String>();
myMap.put("1", "1");
myMap.put("2", "1");
myMap.put("3", "1");
myMap.put("4", "1");
myMap.put("5", "1");
myMap.put("6", "1");
System.out.println("HashMap before iterator: "+myMap);
Iterator<String> it1 = myMap.keySet().iterator();
while(it1.hasNext()){
String key = it1.next();
if(key.equals("3")) myMap.put(key+"new", "new3");
}
System.out.println("HashMap after iterator: "+myMap);
}
}