package org.cloudbus.cloudsim.examples;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.LinkedList;
import java.util.List;
import java.util.Random;
import org.cloudbus.cloudsim.Chromosomes;
import org.cloudbus.cloudsim.Cloudlet;
import org.cloudbus.cloudsim.CloudletSchedulerSpaceShared;
import org.cloudbus.cloudsim.CloudletSchedulerTimeShared;
import org.cloudbus.cloudsim.Datacenter;
import org.cloudbus.cloudsim.DatacenterBroker;
import org.cloudbus.cloudsim.DatacenterCharacteristics;
import org.cloudbus.cloudsim.Gene;
import org.cloudbus.cloudsim.Host;
import org.cloudbus.cloudsim.Log;
import org.cloudbus.cloudsim.Pe;
import org.cloudbus.cloudsim.Storage;
import org.cloudbus.cloudsim.UtilizationModel;
import org.cloudbus.cloudsim.UtilizationModelFull;
import org.cloudbus.cloudsim.Vm;
import org.cloudbus.cloudsim.VmAllocationPolicySimple;
import org.cloudbus.cloudsim.VmSchedulerTimeShared;
import org.cloudbus.cloudsim.core.CloudSim;
import org.cloudbus.cloudsim.provisioners.BwProvisionerSimple;
import org.cloudbus.cloudsim.provisioners.PeProvisionerSimple;
import org.cloudbus.cloudsim.provisioners.RamProvisionerSimple;
/**
* An example showing how to create
* scalable simulations.
*/
public class CloudSimExample6 {
/** The cloudlet list. */
private static List<Cloudlet> cloudletList;
/** The vmlist. */
private static List<Vm> vmlist;
private static List<Vm> createVM(int userId, int vms) {
//Creates a container to store VMs. This list is passed to the broker later
LinkedList<Vm> list = new LinkedList<Vm>();
//VM Parameters
long size = 10000; //image size (MB)
int ram = 512; //vm memory (MB)
int mips = 1000;
long bw = 10;
int pesNumber = 1; //number of cpus
String vmm = "Xen"; //VMM name
//create VMs
Vm[] vm = new Vm[vms];
Random rmips=new Random(100);
for(int i=0;i<vms;i++){
mips=rmips.nextInt(900);
bw=10+rmips.nextInt(50);
vm[i] = new Vm(i, userId, mips, pesNumber, ram, bw, size, vmm, new CloudletSchedulerSpaceShared());
//for creating a VM with a space shared scheduling policy for cloudlets:
//vm[i] = Vm(i, userId, mips, pesNumber, ram, bw, size, priority, vmm, new CloudletSchedulerSpaceShared());
list.add(vm[i]);
}
return list;
}
private static List<Cloudlet> createCloudlet(int userId, int cloudlets){
// Creates a container to store Cloudlets
LinkedList<Cloudlet> list = new LinkedList<Cloudlet>();
//cloudlet parameters
long length = 1000;
long fileSize = 300;
long outputSize = 300;
int pesNumber = 1;
UtilizationModel utilizationModel = new UtilizationModelFull();
Cloudlet[] cloudlet = new Cloudlet[cloudlets];
for(int i=0;i<cloudlets;i++){
Random random = new Random(12);
int x = (int) (random.nextInt(100) * ((2000 - 1) + 1)) + 1;
cloudlet[i] = new Cloudlet(i, length+x, pesNumber, fileSize, outputSize, utilizationModel, utilizationModel, utilizationModel);
// setting the owner of these Cloudlets
cloudlet[i].setUserId(userId);
list.add(cloudlet[i]);
}
return list;
}
////////////////////////// STATIC METHODS ///////////////////////
/**
* Creates main() to run this example
*/
public static void main(String[] args) {
Log.printLine("Starting CloudSimExample6...");
try {
// First step: Initialize the CloudSim package. It should be called
// before creating any entities.
int num_user = 1; // number of grid users
Calendar calendar = Calendar.getInstance();
boolean trace_flag = false; // mean trace events
// Initialize the CloudSim library
CloudSim.init(num_user, calendar, trace_flag);
// Second step: Create Datacenters
//Datacenters are the resource providers in CloudSim. We need at list one of them to run a CloudSim simulation
@SuppressWarnings("unused")
Datacenter datacenter0 = createDatacenter("Datacenter_0");
@SuppressWarnings("unused")
Datacenter datacenter1 = createDatacenter("Datacenter_1");
//Third step: Create Broker
DatacenterBroker broker = createBroker();
int brokerId = broker.getId();
//Fourth step: Create VMs and Cloudlets and send them to broker
vmlist = createVM(brokerId,20); //creating 20 vms
cloudletList = createCloudlet(brokerId,20); // creating 20 cloudlets
int numVMs=vmlist.size();
int numCloudlets=cloudletList.size();
List<Vm> finalvmlist = new ArrayList<Vm>();
double factor=-100000;
int T_MAX=10;
int c=5;
double[][][] T = new double[numVMs+1][numCloudlets+1][T_MAX+1];
int[] M = new int[numVMs+1];
double a=.3;
double Q=100;
//double[] tabu = new double[numVMs+1];
int m=numVMs;
for(int i=0;i<=numVMs;i++)
{
for(int j=0;j<=numCloudlets;j++)
{
for(int k=0;k<=T_MAX;k++)
{
T[i][j][k]=c;
}
}
}
for(int i=0;i<=numVMs;i++)
M[i]=i;
for(int t=0;t<=T_MAX;t++)
{
double[] taskProb = new double[numCloudlets+1];
int[] taskVm = new int[numCloudlets+1];
for(int i=0;i<=numCloudlets;i++){
taskProb[i]=-10000000;
taskVm[i]=0;
}
for(int k=1;k<=m;k++)
{
boolean[] tabu = new boolean[numVMs+1];
for(int i=0;i<=m;i++)
tabu[i]=false;
for(int task=1;task<=numCloudlets;task++)
{
int vmIndex=0;
double ansProb=0;
double reqd=1;
for(int vm=1;vm<=numVMs;vm++)
{
if(tabu[vm]==false)
{
double tempProb=0;
double dij=cloudletList.get(task-1).getCloudletLength();
dij=dij/(vmlist.get(vm-1).getMips()*vmlist.get(vm-1).getNumberOfPes());
tempProb=Math.pow(T[vm][task][t], a);
tempProb/=dij;
if(tempProb>ansProb)
{
ansProb=tempProb;
vmIndex=vm;
reqd=dij;
}
}
}
if(taskProb[task]<ansProb){
taskProb[task]=ansProb;
taskVm[task]=vmIndex;
}
tabu[vmIndex]=true;
double delta=Q/reqd;
T[vmIndex][task][t]+=delta;
}
}
double tmpfactor=0;
for(int i=1;i<=numCloudlets;i++)
{
tmpfactor+=(taskProb[i]);
}
if(tmpfactor>factor)
{
for(int i=1;i<=numCloudlets;i++)
{
finalvmlist.add(vmlist.get(taskVm[i]-1));
}
}
}
broker.submitVmList(finalvmlist);
broker.submitCloudletList(cloudletList);
// Fifth step: Starts the simulation
CloudSim.startSimulation();
// Final step: Print results when simulation is over
List<Cloudlet> newList = broker.getCloudletReceivedList();
CloudSim.stopSimulation();
printCloudletList(newList);
Log.printLine("CloudSimExample6 finished!");
}
catch (Exception e)
{
e.printStackTrace();
Log.printLine("The simulation has been terminated due to an unexpected error");
}
}
private static Datacenter createDatacenter(String name){
// Here are the steps needed to create a PowerDatacenter:
// 1. We need to create a list to store one or more
// Machines
List<Host> hostList = new ArrayList<Host>();
// 2. A Machine contains one or more PEs or CPUs/Cores. Therefore, should
// create a list to store these PEs before creating
// a Machine.
List<Pe> peList1 = new ArrayList<Pe>();
int mips = 1000;
// 3. Create PEs and add these into the list.
//for a quad-core machine, a list of 4 PEs is required:
peList1.add(new Pe(0, new PeProvisionerSimple(mips))); // need to store Pe id and MIPS Rating
peList1.add(new Pe(1, new PeProvisionerSimple(mips)));
peList1.add(new Pe(2, new PeProvisionerSimple(mips)));
peList1.add(new Pe(3, new PeProvisionerSimple(mips)));
//Another list, for a dual-core machine
List<Pe> peList2 = new ArrayList<Pe>();
peList2.add(new Pe(0, new PeProvisionerSimple(mips)));
peList2.add(new Pe(1, new PeProvisionerSimple(mips)));
//4. Create Hosts with its id and list of PEs and add them to the list of machines
int hostId=0;
int ram = 2048; //host memory (MB)
long storage = 1000000; //host storage
int bw = 10000;
hostList.add(
new Host(
hostId,
new RamProvisionerSimple(ram),
new BwProvisionerSimple(bw),
storage,
peList1,
new VmSchedulerTimeShared(peList1)
)
); // This is our first machine
hostId++;
hostList.add(
new Host(
hostId,
new RamProvisionerSimple(ram),
new BwProvisionerSimple(bw),
storage,
peList2,
new VmSchedulerTimeShared(peList2)
)
); // Second machine
//To create a host with a space-shared allocation policy for PEs to VMs:
//hostList.add(
// new Host(
// hostId,
// new CpuProvisionerSimple(peList1),
// new RamProvisionerSimple(ram),
// new BwProvisionerSimple(bw),
// storage,
// new VmSchedulerSpaceShared(peList1)
// )
// );
//To create a host with a oportunistic space-shared allocation policy for PEs to VMs:
//hostList.add(
// new Host(
// hostId,
// new CpuProvisionerSimple(peList1),
// new RamProvisionerSimple(ram),
// new BwProvisionerSimple(bw),
// storage,
// new VmSchedulerOportunisticSpaceShared(peList1)
// )
// );
// 5. Create a DatacenterCharacteristics object that stores the
// properties of a data center: architecture, OS, list of
// Machines, allocation policy: time- or space-shared, time zone
// and its price (G$/Pe time unit).
String arch = "x86"; // system architecture
String os = "Linux"; // operating system
String vmm = "Xen";
double time_zone = 10.0; // time zone this resource located
double cost = 3.0; // the cost of using processing in this resource
double costPerMem = 0.05; // the cost of using memory in this resource
double costPerStorage = 0.1; // the cost of using storage in this resource
double costPerBw = 0.1; // the cost of using bw in this resource
LinkedList<Storage> storageList = new LinkedList<Storage>(); //we are not adding SAN devices by now
DatacenterCharacteristics characteristics = new DatacenterCharacteristics(
arch, os, vmm, hostList, time_zone, cost, costPerMem, costPerStorage, costPerBw);
// 6. Finally, we need to create a PowerDatacenter object.
Datacenter datacenter = null;
try {
datacenter = new Datacenter(name, characteristics, new VmAllocationPolicySimple(hostList), storageList, 0);
} catch (Exception e) {
e.printStackTrace();
}
return datacenter;
}
//We strongly encourage users to develop their own broker policies, to submit vms and cloudlets according
//to the specific rules of the simulated scenario
private static DatacenterBroker createBroker(){
DatacenterBroker broker = null;
try {
broker = new DatacenterBroker("Broker");
} catch (Exception e) {
e.printStackTrace();
return null;
}
return broker;
}
/**
* Prints the Cloudlet objects
* @param list list of Cloudlets
*/
private static void printCloudletList(List<Cloudlet> list) {
int size = list.size();
Cloudlet cloudlet;
String indent = " ";
Log.printLine();
Log.printLine("========== OUTPUT ==========");
Log.printLine("Cloudlet ID" + indent + "STATUS" + indent +
"Data center ID" + indent + "VM ID" + indent + indent + "Time" + indent + "Start Time" + indent + "Finish Time");
DecimalFormat dft = new DecimalFormat("###.##");
for (int i = 0; i < size; i++) {
cloudlet = list.get(i);
Log.print(indent + cloudlet.getCloudletId() + indent + indent);
if (cloudlet.getCloudletStatus() == Cloudlet.SUCCESS){
Log.print("SUCCESS");
Log.printLine( indent + indent + cloudlet.getResourceId() + indent + indent + indent + cloudlet.getVmId() +
indent + indent + indent + dft.format(cloudlet.getActualCPUTime()) +
indent + indent + dft.format(cloudlet.getExecStartTime())+ indent + indent + indent + dft.format(cloudlet.getFinishTime()));
}
}
}
} Write, Run & Share Java code online using OneCompiler's Java online compiler for free. It's one of the robust, feature-rich online compilers for Java language, running the Java LTS version 17. Getting started with the OneCompiler's Java editor is easy and fast. The editor shows sample boilerplate code when you choose language as Java and start coding.
OneCompiler's Java online editor supports stdin and users can give inputs to the programs using the STDIN textbox under the I/O tab. Using Scanner class in Java program, you can read the inputs. Following is a sample program that shows reading STDIN ( A string in this case ).
import java.util.Scanner;
class Input {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter your name: ");
String inp = input.next();
System.out.println("Hello, " + inp);
}
}
OneCompiler supports Gradle for dependency management. Users can add dependencies in the build.gradle file and use them in their programs. When you add the dependencies for the first time, the first run might be a little slow as we download the dependencies, but the subsequent runs will be faster. Following sample Gradle configuration shows how to add dependencies
apply plugin:'application'
mainClassName = 'HelloWorld'
run { standardInput = System.in }
sourceSets { main { java { srcDir './' } } }
repositories {
jcenter()
}
dependencies {
// add dependencies here as below
implementation group: 'org.apache.commons', name: 'commons-lang3', version: '3.9'
}
Java is a very popular general-purpose programming language, it is class-based and object-oriented. Java was developed by James Gosling at Sun Microsystems ( later acquired by Oracle) the initial release of Java was in 1995. Java 17 is the latest long-term supported version (LTS). As of today, Java is the world's number one server programming language with a 12 million developer community, 5 million students studying worldwide and it's #1 choice for the cloud development.
short x = 999; // -32768 to 32767
int x = 99999; // -2147483648 to 2147483647
long x = 99999999999L; // -9223372036854775808 to 9223372036854775807
float x = 1.2;
double x = 99.99d;
byte x = 99; // -128 to 127
char x = 'A';
boolean x = true;
When ever you want to perform a set of operations based on a condition If-Else is used.
if(conditional-expression) {
// code
} else {
// code
}
Example:
int i = 10;
if(i % 2 == 0) {
System.out.println("i is even number");
} else {
System.out.println("i is odd number");
}
Switch is an alternative to If-Else-If ladder and to select one among many blocks of code.
switch(<conditional-expression>) {
case value1:
// code
break; // optional
case value2:
// code
break; // optional
...
default:
//code to be executed when all the above cases are not matched;
}
For loop is used to iterate a set of statements based on a condition. Usually for loop is preferred when number of iterations is known in advance.
for(Initialization; Condition; Increment/decrement){
//code
}
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while(<condition>){
// code
}
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (<condition>);
Class is the blueprint of an object, which is also referred as user-defined data type with variables and functions. Object is a basic unit in OOP, and is an instance of the class.
class keyword is required to create a class.
class Mobile {
public: // access specifier which specifies that accessibility of class members
string name; // string variable (attribute)
int price; // int variable (attribute)
};
Mobile m1 = new Mobile();
public class Greeting {
static void hello() {
System.out.println("Hello.. Happy learning!");
}
public static void main(String[] args) {
hello();
}
}
Collection is a group of objects which can be represented as a single unit. Collections are introduced to bring a unified common interface to all the objects.
Collection Framework was introduced since JDK 1.2 which is used to represent and manage Collections and it contains:
This framework also defines map interfaces and several classes in addition to Collections.
| Collection | Description |
|---|---|
| Set | Set is a collection of elements which can not contain duplicate values. Set is implemented in HashSets, LinkedHashSets, TreeSet etc |
| List | List is a ordered collection of elements which can have duplicates. Lists are classified into ArrayList, LinkedList, Vectors |
| Queue | FIFO approach, while instantiating Queue interface you can either choose LinkedList or PriorityQueue. |
| Deque | Deque(Double Ended Queue) is used to add or remove elements from both the ends of the Queue(both head and tail) |
| Map | Map contains key-values pairs which don't have any duplicates. Map is implemented in HashMap, TreeMap etc. |