mhtmalpani

import java.util.ArrayList;
import java.util.List;

public class ProxyInternet implements Internet {

    private List<String> restrictedUrls;
    private ActualInternet actualInternet;

    public ProxyInternet() {
        createRestrictedUrlList();

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public class ActualInternet implements Internet {

    @Override
    public void connectToUrl(String url) {
        System.out.println("Making connection to: " + url);
    }
}

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public interface Internet {

    void connectToUrl(String url) throws Exception;
}

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public class ProxyPatternMain {

    public static void main(String[] args) {

        Internet internet = new ProxyInternet();

        try {
            internet.connectToUrl("www.google.com");
            internet.connectToUrl("www.facebook.com");
			

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public class BillPughSingleton {

    private BillPughSingleton() {
    }

    private static class SingletonHelper {
        private static final BillPughSingleton INSTANCE = new BillPughSingleton();
    }

    public static BillPughSingleton getInstance() {

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public class ThreadSafeCheckSingleton {

    private static ThreadSafeCheckSingleton instance;

    private ThreadSafeCheckSingleton() {
    }

    public static ThreadSafeCheckSingleton getInstanceUsingDoubleLocking(){
        if(instance == null){
            synchronized (ThreadSafeCheckSingleton.class) {

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public class ThreadSafeSingleton {

    private static ThreadSafeSingleton instance;

    private ThreadSafeSingleton() {
    }

    public static synchronized ThreadSafeSingleton getInstance() {
        if (instance == null) {
            instance = new ThreadSafeSingleton();

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public class LazyInitialisationSingleton {

    private static LazyInitialisationSingleton instance;

    private LazyInitialisationSingleton() {
    }

    //This is initialised only when the object is demanded for the first time
    public static LazyInitialisationSingleton getInstance() {
        if (instance == null) {

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public class StaticBlockSingleton {

    private static StaticBlockSingleton instance;

    private StaticBlockSingleton() {
    }

    //Static block initialization for exception handling
    static {
        try {

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public class Main {

    public static void main(String[] args) {

        EagerSingleton eagerSingleton = EagerSingleton.getInstance();
    }
}