Applet 1

import java.awt.*;
import java.applet.*;

public class interfata_grafica extends Applet{
Font font=new Font("TimeRoman",Font.BOLD,18);
public int value = 0;
public Scrollbar indicate_strength;
@Override
public void init (){
indicate_strength = new Scrollbar(Scrollbar.HORIZONTAL, 0, 0, 0, 6); //scrolul
add(indicate_strength);
}
public void pause(int timp){
try{
Thread.sleep(timp);
}
catch(InterruptedException e){
System.out.println("Erroare");
}
}
@Override
public void paint (Graphics g){
g.drawString("Da-ti scroll pentru primul Arbore = " + value, 10, 40);
if(value==1){
g.setFont(font);
g.drawString("Reprezentarea functie: cos(x)*(sin(x)+x)/4+(ctg(x)-rad(x))",23,23);
g.drawRoundRect(186,258,84,84,84,84);
g.drawString("ln",223,308);
pause(1000);
g.drawRoundRect(510,258,84,84,84,84);
g.drawString("sin",544,308);
pause(1000);
g.drawLine(347,168,252,264);
pause(1000);
g.drawLine(429,168,526,264);
pause(1000);

g.drawRoundRect(346,118,84,84,84,84);
g.drawString("*",382,168);
pause(1000);

g.drawRoundRect(711,258,84,84,84,84);
g.drawString("exp",748,308);
pause(1000);

g.drawRoundRect(1035,258,84,84,84,84);
g.drawString("3",1072,308);
pause(1000);
g.drawLine(862,168,772,264);
pause(1000);
g.drawLine(944,168,1056,264);
pause(1000);

g.drawRoundRect(860,118,84,84,84,84);
g.drawString("-",897,168);
pause(1000);

pause(1000);
g.drawLine(603,70,420,130);
pause(1000);
g.drawLine(686,70,870,130);
pause(1000);

g.drawRoundRect(603,23,84,84,84,84);
g.drawString("+",640,73);
pause(1000000);
}
}
@Override
public boolean handleEvent (Event e){
value = indicate_strength.getValue();
repaint();
return true;
}
}

Tipuri de date primitive

public class index{
public static void care(float f){
System.out.println("Float: " + f);
}
public static void care(double f){
System.out.println("Double " + f);
}
public static void main(String args[]){
care(35);
care(3.6);
}
}

Supraincarcarea Constructorilor

public class index{
private int valoare;
public index(){
valoare=2;
}
public index(int v){
valoare=v;
}
public void seteazaValoare(int v){//scopul acestei metode este setarea unei valori
valoare=v;
}
public void afiseazaValoare(){
System.out.println("Valoarea este: " + valoare);
}
public static void main(String args[]){
index asd=new index();
asd.afiseazaValoare();
}
}

Supraincarcarea Constructorilor

public class index{
private int valoare;
public index(){
valoare=2;
}
public index(int v){
valoare=v;
}
public void seteazaValoare(int v){
valoare=v;
}
public void afiseazaValoare(){
System.out.println("Valoarea este: " + valoare);
}
public static void main(String args[]){
index asd=new index();
asd.afiseazaValoare();
}
}

Supraincarcarea Metodelor

public class index{
void tipareste(String sir,boolean b){
if(b)
System.out.println("String: " + sir);
}
void tipareste(boolean b,String sir){
if(b)
System.out.println("String: " + sir);
}
public static void main(String args[]){
index asd=new index();
asd.tipareste("Noroc1", true);
asd.tipareste(true, "Noroc2");
}
}

Accesarea variabilelor PRIVATE

public class Constructor{
private int camp=17;
public Constructor(int c){
camp=c;
}
public void afiseaza(){
System.out.println("Cimpul este: " + camp);
}
}

//urmatoarea clasa

public class ClientConstructor {
public static void main(String args[]){
Constructor c;
c=new Constructor(20);
c.afiseaza();
}
}

Arata codul sursa HTML dintr-un site!!!

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;

public class Main {
public static void main(String[] args) throws Exception {
URL myURL = new URL("http://zvon.md");
BufferedReader so = new BufferedReader(new InputStreamReader(myURL.openStream()));
while (true) {
String output = so.readLine();
if (output != null) {
System.out.println(output);
} else {
break;
}
}
so.close();
}
}