java s gui-k a - sze
TRANSCRIPT
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
Java Appletek I.
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
Java és GUI-k
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
3
Webtechnológia 1
AWT, Swing
• Abstract Window Toolkit
• sok UI komponens
• eseménykezelés
• grafikus eszközök
• layout managerek
• Swing
• pluggable look & feel
• lightweight UI Framework
• magas szint! komponensek
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
4
Webtechnológia 1
MVC és Swing alkalmazás
View Controller Model
Window obj. Listener obj. Data obj.Events Messages
Update
Java UI components
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
5
Webtechnológia 1
Swing áttekintés
• JComponent
• Az alkalmazás vagy applet összes látható eleme component
• A Container osztály példányai komponensek csoportjait tartalmazzák
• add metódus
2
2000 Prentice Hall, Inc. All rights reserved.
3
12.2 Swing Overview
• Swing component inheritance hierarchy
• Component defines methods that can be used in itssubclasses (for example, paint and repaint)
• Container - collection of related components
– When using JFrames, attach components to the contentpane (a Container)
– Method add• JComponent - superclass to most Swing components
• Much of a component's functionality inherited from theseclasses
java.awt.Component
java.awt.Container
java.lang.Object
javax.swing.JComponent
2000 Prentice Hall, Inc. All rights reserved.
4
12.2 Swing Overview
• Some capabilities of subclasses of JComponent– Pluggable look and feel
– Shortcut keys (mnemonics)
• Direct access to components through keyboard
– Common event handling
• If several components perform same actions
– Tool tips
• Description of component that appears when mouse over it
• Swing vs. awt?
– Different components
• Java 1.0 vs. Java 1.1 vs. Java 1.2?
– Different event model
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
6
Webtechnológia 1
Swing áttekintés (folyt.)
• JComponent legfontosabb tulajdonságai
• pluggable look&feel
• shortcut keys
• közös eseménykezelés lehetséges
• tool tipek
• Swing vagy AWT
• különböz" komponensek
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
7
Webtechnológia 1
Java eseménykezelési modellje
• Eseményvezérelt GUI
• eseménygenerálás, ha a felhasználó interakcióba lép egy GUI komponenssel
• esemény infók tárolása AWTEvent leszármazottakban
• Események feldolgozása
• eseményfigyel" regisztrálása
• event-listener interface implementálása
• eseménykezel" implementálása
• eseményre válaszul meghívandó metódusok
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
8
Webtechnológia 1
Java eseménykezelési modellje (folyt.)
• Delegációs esemény modell
• esemény figyel"k használata
• az objektum számára érdekes események feldolgozása
• Esemény bekövetkeztekor
• GUI komponens értesíti a figyel"ket
• figyel" meghívja az eseménykezel" metódust
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
9
Webtechnológia 1
Események
• Különféle események
• ActionEvent
• képerny"gomb megnyomása
• AdjustmentEvent
• scrollbar mozgatása
• MouseEvent
• egér koordináták
• KeyEvent
• billenty! kód, karakter
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
10
Webtechnológia 1
Adapter osztályok
• El"regyártott Adapter osztályok
• Listener interface-eket implementáló abstract osztályok
• leszármaztatottban a kívánt metódus felülírható
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
11
Webtechnológia 1
Swing komponensekés az MVC
• Maguk a Swing komponensek MVC struktúrájúak
• JComponent-eknek van model-jük
• pl. JButton -> ButtonModel
• view és controller absztrakt UI delegáltakban
• javax.swing.plaf
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
12
Webtechnológia 1
Swing osztályok
JComponent
JTextComponent
AbstractButton
JComboBox
JLabel
JList
JMenuBar
JPane
JPopupMenu
JScrollbar
JScrollPane
JTable
JTree
JToggleButton JButton JMenuItem
JCheckBox JRadioButton
JRadioButtonMenuItem JCheckBoxMenuItem
ContainerComponentObject
JPanel
JApplet
AppletPanel
JMenu
FontColor
JTextAreaJTextField
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
13
Webtechnológia 1
Swing GUI komponensek
Demo program at jdk1.4/demo/jfc/SwingSet2/SwingSet2.html
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
14
Webtechnológia 1
Layout kezelés
• Automatikus átrendezés
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
15
Webtechnológia 1
Border layout
public class TestBorderLayout extends JApplet { public void init() { Container guiContainer = getContentPane(); Font big = new Font("SansSerif", Font.BOLD, 20); JButton buttonOne = new JButton("1"); buttonOne.setFont(big); guiContainer.add(buttonOne, BorderLayout.WEST); JButton buttonTwo = new JButton("2"); buttonTwo.setFont(big); guiContainer.add(buttonTwo, BorderLayout.CENTER); JButton buttonThree = new JButton("3"); buttonThree.setFont(big); guiContainer.add(buttonThree, BorderLayout.EAST); JButton buttonFour = new JButton("4"); buttonFour.setFont(big); guiContainer.add(buttonFour, BorderLayout.NORTH); JButton buttonFive = new JButton("5"); buttonFive.setFont(big); guiContainer.add(buttonFive, BorderLayout.SOUTH); }}
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
16
Webtechnológia 1
GridLayoutpublic class TestGridLayout extends JApplet { private JTextField name = new JTextField(15); private JTextField address = new JTextField(15); private JTextField phone = new JTextField(15); private JTextField eMail = new JTextField(15);
public void init() { Container guiContainer = getContentPane(); guiContainer.setLayout(new GridLayout(4, 2, 5, 5));
JLabel label = new JLabel("Name:", JLabel.RIGHT); guiContainer.add(label); guiContainer.add(name); label = new JLabel("Address:", JLabel.RIGHT); guiContainer.add(label); guiContainer.add(address); label = new JLabel("Phone:", JLabel.RIGHT); guiContainer.add(label); guiContainer.add(phone); label = new JLabel("E-mail:", JLabel.RIGHT); guiContainer.add(label); guiContainer.add(eMail); }}
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
17
Webtechnológia 1
GridBagLayout
• GridBagLayout is the most general of all the layout managers, and often the only applicable.
• It’s not suited for the trial end error method.
• To use it you have to do a careful planning. Use pen and paper!
• The manager has many parameters, and an error may give unpredictable results.
• First, create a sketch of the window:
• Divide the window into rectangular cells by using vertical and horizontal lines.
• Not more than one GUI component in every cell.
• A GUI component may cover more than one cell.
• This sketch makes it possible to state the requirements of every component.
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
18
Webtechnológia 1
GridBag példa
toolbar
table on
the left
list on
the right
backgr. text
at the ottom
text box at
the bottom
gridx 0 0 3 1 2
gridy 0 1 1 2 2
gridwidth 4 3 1 1 1
gridheight 1 1 1 1 1
fill NONE BOTH BOTH NONE HORIZONTAL
anchor WEST CENTER CENTER EAST WEST
0
1
2
0 1 2 3
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
19
Webtechnológia 1
GridBag példa (folyt.)
Container guiContainer = getContentPane();
guiContainer.setLayout(new GridBagLayout()); // don’t forget this!
GridBagConstraints constraints = new GridBagConstraints();
/* The following variables are fixed for all components */
constraints.insets = new Insets(5, 5, 5, 5); // space around and between the components
constraints.weightx = 0.5;
constraints.weighty = 0.5;
/* Then each component has to be handled according to the table */
/* The Toolbar */
constraints.gridx = 0;
constraints.gridy = 0;
constraints.gridwidth = 4;
constraints.gridheight = 1;
constraints.fill = GridBagConstraints.NONE;
constraints.anchor = GridBagConstraints.WEST;
guiContainer.add(toolbar, constraints);
// ..and so on, for all the components
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
Appletek
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
21
Webtechnológia 1
Hello world applet
import javax.swing.JApplet;
import java.awt.Graphics;
public class HelloWorld extends JApplet {
public void paint(Graphics g) {
g.drawRect(0, 0,
getSize().width - 1,
getSize().height - 1);
g.drawString("Hello world!", 5, 15);
}
}
<applet code="HelloWorld.class" codebase="examples/" archive="helloWorld.jar" width="150" height="30"></applet>
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
22
Webtechnológia 1
Appletek
Object
Component
JFrame JApplet
JInternalFrame Dialog
JDialog
Container
WindowJComponent Panel
FrameJWindow Applet
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
23
Webtechnológia 1
Appletek (folyt.)
• grafikus kisalkalmazás
• böngész" vagy appletviewer kontextus
• java.applet.Applet vagy javax.swing.JApplet specializálása
• standard interfész
• homokozó (sandbox)
• SecurityManager
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
24
Webtechnológia 1
Appletéletciklus
The applet is stopped, the user has left theWeb page.
init() start()
start()
stop()
destroy()
The applet isloaded and startsright away.
The applet isrunning, theuser is watching.
The applet is out of theworld because thebrowser is closed, or foranother reason.
loaded running stopped dead
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
25
Webtechnológia 1
Appletéletciklus (folyt.)
/*
* Java(TM) SE 6 Version
*/
import java.applet.Applet;
import java.awt.Graphics;
//No need to extend JApplet, since we don't add any components;
//we just paint.
public class Simple extends Applet {
StringBuffer buffer;
public void init() {
buffer = new StringBuffer();
addItem("initializing... ");
}
public void start() {
addItem("starting... ");
}
public void stop() {
addItem("stopping... ");
}
public void destroy() {
addItem("preparing for unloading...");
}
private void addItem(String newWord) {
System.out.println(newWord);
buffer.append(newWord);
repaint();
}
public void paint(Graphics g) {
//Draw a Rectangle around the applet's display area.
g.drawRect(0, 0,
getWidth() - 1,
getHeight() - 1);
//Draw the current string inside the rectangle.
g.drawString(buffer.toString(), 5, 15);
}
}
appletviewer lifeCycle.html
initializing...
starting...
stopping...
preparing for unloading...
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
26
Webtechnológia 1
Appletéletciklus (folyt.)
• init metódus
• constructor szer! m!veletek elvégzése, teljes contextus
• start metódus
• az applet tevékenysége
• szálak indítása
• stop metódus
• er"források elengedése
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
27
Webtechnológia 1
Megjelenítés
• Applet megjelenítés a paint metódussal
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
28
Webtechnológia 1
Eseménykezelés/*
* Java(TM) SE 6 version.
*/
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
import java.applet.Applet;
import java.awt.Graphics;
//No need to extend JApplet, since we don't add any components;
//we just paint.
public class SimpleClick extends Applet
implements MouseListener {
StringBuffer buffer;
public void init() {
addMouseListener(this);
buffer = new StringBuffer();
addItem("initializing... ");
}
public void start() {
addItem("starting... ");
}
public void stop() {
addItem("stopping... ");
}
public void destroy() {
addItem("preparing for unloading...");
}
void addItem(String newWord) {
System.out.println(newWord);
buffer.append(newWord);
repaint();
}
public void paint(Graphics g) {
//Draw a Rectangle around the applet's display area.
g.drawRect(0, 0,
getWidth() - 1,
getHeight() - 1);
//Draw the current string inside the rectangle.
g.drawString(buffer.toString(), 5, 15);
}
//The following empty methods could be removed
//by implementing a MouseAdapter (usually done
//using an inner class).
public void mouseEntered(MouseEvent event) {
}
public void mouseExited(MouseEvent event) {
}
public void mousePressed(MouseEvent event) {
}
public void mouseReleased(MouseEvent event) {
}
public void mouseClicked(MouseEvent event) {
addItem("click!... ");
}
}
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
29
Webtechnológia 1
UI komponensek appletben
• Swing komponensek
• Applet -> Container
• add, remove
• setLayout
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
30
Webtechnológia 1
UI komponensek appletben (pl.)
/*
* Java(TM) SE 6 version.
*/
import javax.swing.JApplet;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
//Since we're adding a Swing component, we now need to
//extend JApplet. We need to be careful to access
//components only on the event-dispatching thread.
public class ScrollingSimple extends JApplet {
JTextField field;
public void init() {
//Execute a job on the event-dispatching thread:
//creating this applet's GUI.
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
createGUI();
}
});
} catch (Exception e) {
System.err.println("createGUI didn't successfully complete");
}
addItem(false, "initializing... ");
}
private void createGUI() {
//Create the text field and make it uneditable.
field = new JTextField();
field.setEditable(false);
//Set the layout manager so that the text field will be
//as wide as possible.
getContentPane().setLayout(new java.awt.GridLayout(1,0));
//Add the text field to the applet.
getContentPane().add(field);
}
public void start() {
addItem(false, "starting... ");
}
public void stop() {
addItem(false, "stopping... ");
}
public void destroy() {
addItem(false, "preparing for unloading...");
cleanUp();
}
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
31
Webtechnológia 1
UI komponensek appletben (pl.)
private void cleanUp()
//Execute a job on the event-dispatching thread:
//taking the text field out of this applet.
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
remove(field);
}
});
} catch (Exception e) {
System.err.println("cleanUp didn't successfully complete");
}
field = null;
}
private void addItem(boolean alreadyInEDT, String newWord) {
if (alreadyInEDT) {
addItem(newWord);
} else {
final String word = newWord;
//Execute a job on the event-dispatching thread:
//invoking addItem(newWord).
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
addItem(word);
}
});
} catch (Exception e) {
System.err.println("addItem didn't successfully complete");
}
}
}
//Invoke this method ONLY from the event-dispatching thread.
private void addItem(String newWord) {
String t = field.getText();
System.out.println(newWord);
field.setText(t + newWord);
}
}
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
32
Webtechnológia 1
A homokozó
• browser security policy
• SecurityManager
• SecurityException
• korlátozások
• An applet cannot load libraries or define native methods.
• It cannot ordinarily read or write files on the host that's executing it.
• It cannot make network connections except to the host that it came from.
• It cannot start any program on the host that's executing it.
• It cannot read certain system properties.
• Windows that an applet brings up look di#erent than windows that an application brings up.
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
33
Webtechnológia 1
Applet sajátosságok
• Alkalmazásoktól eltér" lehet"ségek
• Applets can usually make network connections to the host they came from.
• Applets running within a Web browser can easily cause HTML documents to be displayed.
• Applets can invoke public methods of other applets on the same page.
• Applets that are loaded from the local file system (from a directory in the user's CLASSPATH) have none of the restrictions that applets loaded over the network do.
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
34
Webtechnológia 1
Az applet API
• Az appletek az API-n keresztül
• értesülhetnek az applet futási állapotváltozásairól
• az applet vagy beágyazó oldal URL-jéhez relatív elérési utakkal fájlokat tölthetnek le
• írhatnak a browser státusz-sorába
• megjeleníthatnek dokumentumokat a browserben
• paramétereket olvashatnak az applet tagb"l
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
35
Webtechnológia 1
Fájlok letöltése
• getCodeBase
• getDocumentBase
• getImage
• gif, jpeg
• MediaTracker
• getAudioClip
• wav,midi,ai#,au
• URL osztály
class file
a.png
imgDir
Image image = getImage(getCodeBase(), "imgDir/a.png");
com xcompany xproj
class file
a.png
imgDir
package com.xcompany.xproj;
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
36
Webtechnológia 1
MediaTracker// Create a MediaTracker instance,
// to montior loading of images
tracker = new MediaTracker(this);
// Load the image
Image img = getImage( getDocumentBase(),"picture.jpg" );
// Register it with media tracker
tracker.addImage(img, 1);
// Check to see if it has loaded
if (tracker.checkID(1) == false)
{
// Not yet, display message .....
}
else
{
// Display the animation
}
// Wait until all images have loaded
tracker.waitForAll();
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
37
Webtechnológia 1
Fájlok letöltése (pl.)
import javax.swing.*;
import java.awt.*;
/** Demonstrate drawing an image. **/
public class ImageApplet extends JApplet
{
public void init () {
Container content_pane = getContentPane ();
// Grab the image.
Image img = getImage (getCodeBase (), "liftoff.jpg");
// Create an instance of DrawingPanel
DrawingPanel drawing_panel = new DrawingPanel (img);
// Add the DrawingPanel to the contentPane.
content_pane.add (drawing_panel);
} // init
} // ImageApplet
/** Draw on a JPanel rather than on JApplet's Panel. **/
class DrawingPanel extends JPanel {
Image img;
DrawingPanel (Image img) {
this.img = img;
}
public void paintComponent (Graphics g) {
super.paintComponent (g);
// Use the image width& width to find the starting point
int img_x = getSize ().width/2 - img.getWidth (this)/2;
int img_y = getSize ().height/2 - img.getHeight (this)/2;
//Draw image at centered in the middle of the panel
g.drawImage (img, img_x, img_y, this);
} // paintComponent
} // class DrawingPanel
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
38
Webtechnológia 1
Dokumentum megjelenítés a böngész!ben
• public void showDocument(java.net.URL url)
• public void showDocument(java.net.URL url, String targetWindow)
• browser ablakok
• _blank
• új, névtelen ablak
• _self
• az applet ablaka
• _parent
• keretek esetén a frameset ablaka
• _top
• legmagasabb szint! frameset ablaka
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
39
Webtechnológia 1
Dokumentum megjelenítés a böngész!ben (pl.)
/*
* Java(TM) SE 6 version.
*/
import java.applet.AppletContext;
import javax.swing.*;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Insets;
import java.awt.event.*;
import java.net.URL;
import java.net.MalformedURLException;
public class ShowDocument extends JApplet
implements ActionListener {
URLWindow urlWindow;
public void init() {
//Execute a job on the event-dispatching thread:
//creating this applet's GUI.
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
createGUI();
}
});
} catch (Exception e) {
System.err.println("createGUI didn't successfully complete");
}
}
private void createGUI() {
JButton button = new JButton("Bring up URL window");
button.addActionListener(this);
getContentPane().add(button);
JFrame.setDefaultLookAndFeelDecorated(true);
urlWindow = new URLWindow(getAppletContext());
urlWindow.pack();
}
public void destroy() {
//Execute a job on the event-dispatching thread:
//creating this applet's GUI.
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
destroyGUI();
}
});
} catch (Exception e) { }
}
private void destroyGUI() {
urlWindow.setVisible(false);
urlWindow = null;
}
public void actionPerformed(ActionEvent event) {
urlWindow.setVisible(true);
}
}
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
40
Webtechnológia 1
Dokumentum megjelenítés a böngész!ben (pl.)
class URLWindow extends JFrame
implements ActionListener {
JTextField urlField;
JComboBox choice;
AppletContext appletContext;
public URLWindow(AppletContext appletContext) {
super("Show a Document!");
this.appletContext = appletContext;
JPanel contentPane = new JPanel(new GridBagLayout());
setContentPane(contentPane);
contentPane.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL;
JLabel label1 = new JLabel("URL of document to show: ",
JLabel.TRAILING);
getContentPane().add(label1, c);
urlField = new JTextField("http://java.sun.com/", 20);
label1.setLabelFor(urlField);
urlField.addActionListener(this);
c.gridwidth = GridBagConstraints.REMAINDER;
c.weightx = 1.0;
getContentPane().add(urlField, c);
JLabel label2 = new JLabel("Window/frame to show it in: ",
JLabel.TRAILING);
c.gridwidth = 1;
c.weightx = 0.0;
getContentPane().add(label2, c);
String[] strings = {
"(browser's choice)", //don't specify
"My Personal Window", //a window named "My Personal Window"
"_blank", //a new, unnamed window
"_self",
"_parent",
"_top" //the Frame that contained this applet
};
choice = new JComboBox(strings);
label2.setLabelFor(choice);
c.fill = GridBagConstraints.NONE;
c.gridwidth = GridBagConstraints.REMAINDER;
c.insets = new Insets(5,0,0,0);
c.anchor = GridBagConstraints.LINE_START;
getContentPane().add(choice, c);
JButton button = new JButton("Show document");
button.addActionListener(this);
c.weighty = 1.0;
c.ipadx = 10;
c.ipady = 10;
c.insets = new Insets(10,0,0,0);
c.anchor = GridBagConstraints.PAGE_END;
getContentPane().add(button, c);
}
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
41
Webtechnológia 1
Dokumentum megjelenítés a böngész!ben (pl.)
public void actionPerformed(ActionEvent event) {
String urlString = urlField.getText();
URL url = null;
try {
url = new URL(urlString);
} catch (MalformedURLException e) {
System.err.println("Malformed URL: " + urlString);
}
if (url != null) {
if (choice.getSelectedIndex() == 0) {
appletContext.showDocument(url);
} else {
appletContext.showDocument(url,
(String)choice.getSelectedItem());
}
}
}
}
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
42
Webtechnológia 1
Státusz-sor
• átmeneti státusz információk kiírása
import!java.applet.AppletContext;
import!java.awt.Graphics;
import!java.net.URL;
import!javax.swing.JApplet;
public!class!MainClass!extends!JApplet!{
!!public!void!paint(Graphics!g)!{
!!!!AppletContext!ac!=!getAppletContext();
!!!!try!{
!!!!!!URL!url!=!new!URL("http://www.java2s.com");
!!!!!!ac.showDocument(url,!"frame2");
!!!!}!catch!(Exception!e)!{
!!!!!!showStatus("Exception:!"!+!e);
!!!!}
!!!!g.drawString("ShowDocument!Applet",!10,!25);
!!}
}
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
43
Webtechnológia 1
Applet paraméterek
• commandline paraméterekhez hasonló használat
• flexibilis felhasználás
• paraméterek
• név
• értékkészlet
• default érték
<APPLET CODE=SampleApplet.class CODEBASE=example
WIDTH=350 HEIGHT=60>
<PARAM NAME=windowClass VALUE=BorderWindow>
<PARAM NAME=windowTitle VALUE="BorderLayout">
<PARAM NAME=buttonText
VALUE="Click here to see a BorderLayout in action">
</APPLET>
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
44
Webtechnológia 1
Applet paraméterek (folyt.)
public String getParameter(String name)
int requestedWidth = 0; //default value
. . .
String windowWidthString = getParameter("WINDOWWIDTH");
if (windowWidthString != null) {
try {
requestedWidth = Integer.parseInt(windowWidthString);
} catch (NumberFormatException e) {
//Use default width.
}
}
THEINTERNET,mapped on the opposite page, is a scale-free network in that
some siteS (starbursts and detail above) have a seemingly unlimitednumber of connections to other sites. This map, made on February 6, 2003,
traces the shortest routes from atest WebsinHo about 100,000 others,
using like colors for similar Webaddresses.
a -
Scientistshaverecentlydiscoveredthat variouscomplexsystemshave
antlnderlyihg~..'~tJ;i~e~tu"eg~Ye'l"rne(;lb9.$haredorganili ngprincipies.
Thisinsighthas important impli~ationsfor a hostof
applications,fromdrugdevelopmentto Internetsecurity
BYALBERT-U\SZLOBARABASIANDERICBONABEAU
50 SCIENTIFIC AMERICAN MAY 2003
45
Webtechnológia 1
Applet paraméterek (folyt.)
• Paraméter információk megadásapublic String[][] getParameterInfo() {
String[][] info = {
// Parameter Name Kind of Value Description
{"imagesource", "URL", "a directory"},
{"startup", "URL", "displayed at startup"},
{"background", "URL", "displayed as background"},
{"startimage", "int", "start index"},
{"endimage", "int", "end index"},
{"namepattern", "URL", "used to generate indexed names"},
{"pause", "int", "milliseconds"},
{"pauses", "ints", "milliseconds"},
{"repeat", "boolean", "repeat or not"},
{"positions", "coordinates", "path"},
{"soundsource", "URL", "audio directory"},
{"soundtrack", "URL", "background music"},
{"sounds", "URLs", "audio samples"},
};
return info;
}