Praktikum 8

package Praktikum8;

import java.util.*;
import java.util.Random;
import static jsTools.Input.*;

// zur Zeitmessung der benoetigten Rechenzeit benoetigt:
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadMXBean;

class Person {
	String name;
	String vorname;

	Person(String vn, String nn) {
		name = nn;
		vorname = vn;
	}

	public String toString() {
		return ">" + vorname + ", " + name + "<\n";
	}
}

public class CollTest {
	// Variable, Methoden fuer die Zeitmessung
	private static ThreadMXBean tb = ManagementFactory.getThreadMXBean();
	private static long starttime, timeused;

	private static void startClock() {
		starttime = tb.getCurrentThreadCpuTime();
	}

	private static void stopClock(String txt) {
		timeused = tb.getCurrentThreadCpuTime() - starttime;
		System.out.println(txt + ": " + (float) timeused);
	}

	// Ende der Zeitmessungselemente

	// diese insertMethode zeigt die Anzahl der Elemente vor und
	// nach dem Einfuegen an. Daraus kann man ableiten, ob tatsaechlich eingefuegt
	// wurde
	public static void insert(String s, Collection<String> c) {
		System.out.print("Inserting:" + s + " size=" + c.size());
		c.add(s);
		System.out.println(" - inserted size=" + c.size());
	}

	public static void main(String[] args) {
		// ArrayList, LinkedList, Vector, Stack und HashSet
		startClock();
		System.out.println("ArrayList");
		List<Person> personen = Arrays.asList(new Person("Steve", "Vai"), new Person("Steve", "Vai"),
				new Person("Hans", "Schneider"), new Person("Jorje", "Gonzales"), new Person("Jane", "Michaels"),
				new Person("Jo", "Berlin"));
		stopClock("Dauer...");
		for (Person p : personen)
			System.out.println(p);
		System.out.println("−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−");

		startClock();
		System.out.println("LinkedList");
		LinkedList<String> list = new LinkedList<String>();
		list.add("Anja");
		list.add("Karl");
		list.add("Katharina");
		list.add("Anja");
		stopClock("Dauer...");
		for (String p : list)
			System.out.println(p);
		System.out.println("−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−");

		startClock();
		System.out.println("Vector");
		Vector<Person> vec = new Vector<Person>();
		vec.add(new Person("Geier", "Walli"));
		vec.add(new Person("Geier", "Walli"));
		vec.add(new Person("Max", "Mayr"));
		vec.add(new Person("Hans", "Busch"));
		vec.add(2, new Person("Mustermann", "Max"));
		stopClock("Dauer...");
		for (Person p : vec)
			System.out.println(p);
		System.out.println("−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−");

		startClock();
		System.out.println("Stack");
		Collection<String> col = new Stack<String>();
		insert("Bla", col);
		insert("Bla", col);
		insert("blabla", col);
		stopClock("Dauer...");
		System.out.println("−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−");

		startClock();
		System.out.println("HashSet");
		HashSet<String> set = new HashSet<String>();
		set.add("Anja");
		set.add("Karl");
		set.add("Katharina");
		set.add("Anja");
		Iterator it = set.iterator();
		while (it.hasNext())
			System.out.println(it.next());
		for (String name : set)
			System.out.println(name);
		stopClock("Dauer...");

		System.out.println("");
		System.out.println("============================================");
		System.out.println("=========== UND JETZT DIE MAPS =============");
		System.out.println("============================================");
		System.out.println("");

		startClock();
		System.out.println("HashMap");
		AbstractMap<Integer, Person> studKartei = new HashMap<Integer, Person>();
		System.out.println("Map vom Typ: " + studKartei.getClass().getName());

		studKartei.put(1, new Person("Mueller", "Hans"));
		studKartei.put(1, new Person("Mueller", "Hans"));
		studKartei.put(2, new Person("Mueller", "Hans"));
		studKartei.put(3, new Person("Mayer", "Hans"));
		studKartei.put(4, new Person("Huber", "Hans"));
		studKartei.put(2, new Person("Der", "Anet")); // Bayerisch: "der auch nicht"
		System.out.println(studKartei);
		stopClock("Dauer...");
		System.out.println("−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−");

		startClock();
		System.out.println("TreeMap");
		TreeMap<String, Person> map = new TreeMap<String, Person>();
		Person st1 = new Person("Brang","Rainer");
		Person st2 = new Person("Anja","Maier");
		Person st3 = new Person("Katharina","Schwarz");
		Person st4 = new Person("Brang","Rainer");
		map.put(new String(st1.name),st1);
		map.put(new String(st2.name),st2);
		map.put(new String(st3.name),st3);
		map.put(new String(st4.name),st4);
		stopClock("Dauer...");
		for (Person p : map.values())
			System.out.println(p);

	    int h=readInteger("Matnummer:");
		// Performancetest:
		// insert:
		int anz = 100000;

		// CPU-Zeit aufnehmen:
		startClock();

		for (long i = 0; i < anz; i++) {
			int h1 = (int) (Math.random() * 1000000);
			studKartei.put(h1, new Person("Pers", "X" + h));
		}
		// benoetigte Zeit aufnehmen / berechnen
		stopClock("Einfuegezeit");

		// und jetzt viele Ausleseversuche, damit die Zeit statistisch
		// aussagekraeftig ist
		// das Ergebnis der Suchabfrage get wird nicht ausgewertet.
		startClock();

		for (long i = 0; i < anz * 10; i++) {
			int h2 = (int) (Math.random() * 1000000);
			studKartei.get(h2);
		}
		stopClock("Zeit zum Lesen");
	}
}