Vetores no Java ME

Voltar para Programação para Dispositivos Móveis

Classe Principal

 1import javax.microedition.midlet.*;
 2import javax.microedition.lcdui.*;
 3
 4public class Main extends MIDlet {
 5	private VectorCanvas vector;
 6	private Display display;
 7
 8	public Main() {
 9		display = Display.getDisplay(this);
10		vector = new VectorCanvas();
11	}
12
13	public void startApp() {
14		display.setCurrent(vector);
15	}
16
17	public void pauseApp() {
18	}
19
20	public void destroyApp(boolean unconditional) {
21	}
22}

Classe VectorCanvas

 1import java.util.Enumeration;
 2import java.util.Vector;
 3import javax.microedition.lcdui.Canvas;
 4import javax.microedition.lcdui.Graphics;
 5
 6class VectorCanvas extends Canvas {
 7	private int position = 0;
 8	
 9	public void paint(Graphics g) {
10		Vector vector = new Vector(3, 2);
11		println(g, "Tamanho do vetor: " + vector.size());
12		println(g, "Capacidade do vector: " + vector.capacity());
13
14		vector.addElement(new Integer(1));
15		vector.addElement(new Integer(2));
16		vector.addElement(new Integer(3));
17		vector.addElement(new Integer(4));
18		println(g, "Capacidade, depois de adicionados");
19		println(g, "--> elementos: " + vector.capacity());
20
21		vector.addElement(new Double(5));
22		println(g, "Capacidade atual: " + vector.capacity());
23
24		vector.addElement(new Double(6.1));
25		vector.addElement(new String("A7"));
26		println(g, "Capacidade atual: " + vector.capacity());
27
28		vector.addElement(new Float(9.23));
29		vector.addElement(new Integer(10));
30		println(g, "Capacidade atual: " + vector.capacity());
31
32		vector.addElement(new Integer(11));
33		vector.addElement(new Integer(12));
34		println(g, "Primeiro elemento: " + (Integer) vector.firstElement());
35		println(g, "Segundo elemento: " + (Integer) vector.lastElement());
36
37		if (vector.contains(new Integer(3))) {
38			println(g, "O vetor possui o numero 3.");
39		}
40
41		Enumeration vEnum = vector.elements();
42		String elementos = "";
43		while (vEnum.hasMoreElements()) {
44			elementos += " " + vEnum.nextElement();
45		}
46		println(g, "\nElementos no vetor:");
47		println(g, "--> " + elementos);
48	}
49	
50	private void println(Graphics g, String texto) {
51		g.drawString(texto, 0, position, Graphics.LEFT|Graphics.TOP);
52		position += 10;
53	}
54}

Exercício

Crie uma pequena aplicação utilizando-se dos recursos de Vector e Canvas do Java ME. Procure pesquisar novos elementos, utilizar imagens, etc.