I am not sure how to fully express this but, I have probably gone through 10 pages of Google links on this topic and not one of them has helped me solve my issue.
I thought it would be simple enough, I was just trying to add an image to the paint function of my java applet, like any other shape, but this has turned out to be a nightmare for me.
The problem is that every time I try to run the drawImage function it keeps saying Access Denied ("java.io.FilePermission" "Image.jpg" "read"). Yet, none of the tutorials mention this at all, all they ever say is that I should do the following:
import java.applet.*;
import java.awt.*;
Image img;
//These would go in the paint function
img=getImage(getDocumentBase(),"/Image.jpg"); //I have tried without the slash too
g.drawImage(img,20,20,this);
This is all they do and it works for them, but it just won't work for me. Other methods are far too complex for the sake of just adding an image, and even when I go through the toil of doing those it keeps giving me the "Access Denied" message. There's also the method of "signing" it, but I really don't think that's going to help given all that I have tried, so I am afraid it might just be another wasted endeavor. None of the tutorials even tell you to have your applet signed.
I have the image in the "build" (also called bin) folder together with the classes.
The program seemed to run when I included the entire file path, but even then the image did not display. That is not to mention I can't really include the complete path from my own computer because then it wouldn't work when I actually send it to another person.
Please, I just want to know why it doesn't work for me yet seems to work perfectly for others. That, and if there's a way around this.
This is an example of what I am doing:
import java.applet.*;
import java.awt.*;
public class JavaProject extends JApplet
{
Image img;
public void init()
{
img=getImage(getDocumentBase(),"/Image.jpg");
}
public void paint(Graphics g)
{
super.paint(g);
g.drawImage(img,20,20,this);
}
}
This is my HTML file:
<html>
<head>
<title> My First Web Page </title>
</head>
<body>
<applet code="JavaProject.class" width="400" height="500">
</applet>
</body>
</html>
According JApplet java docs method getImage(URL url, String name) should have two parameter: URL-link to picture and String name.
Is method getDocumentBase() returnig an URL-link?
You must start by understanding that an Applet, unless signed, may not read from the file system. It must use either classpath resources or things fetched from the same place it was fetched from. You have to decide which of these applies to you. If the image is a fixed image, you can put it in your classpath as a resource, and use Class.getResourceAsStream. If it's a different image every time, you'll have to use HTTP.
Try this one if the image in the "build" (also called bin) folder together with the classes.
import java.awt.Graphics;
import java.awt.Image;
import java.net.URL;
import javax.swing.JApplet;
public class JavaProject extends JApplet {
Image img;
public void init() {
img = getImage(getDocumentBase(), "images/222.png");
// Please ensure that 222.png is placed under bin/images folder directly
}
#Override
public void paint(Graphics g) {
update(g);
}
#Override
public void update(Graphics g) {
g.drawImage(img, 20, 20, this);
}
}
Try with HTTP URL first
URL myURL = new URL("https://www.gravatar.com/avatar/a94613cea642e6e9e2105867bc2e103e?s=32&d=identicon&r=PG&f=1");
img = getImage(myURL);
If you are using Eclipse under Windows then have a look at below screenshot:
Please have a look at below post to get some understanding about it.
java.io.FilePermission exception - Read from jar file?
Related
I think I'm doing everything right in my code but my background won't show up in my processing project, here is my code.
package finalproject;
import processing.core.PApplet;
import processing.core.PImage;
public class FinalProject extends PApplet {
PImage background;
PImage player;
public void setup() {
size(1360, 1080);
player = loadImage("player.png");
background = loadImage("rust.png");
}
public void draw() {
background(background);
image(player, 500, 500);
}
}
Processing expects files to be inside a data directory next to the code.
You're presumably running this from an IDE like Eclipse instead of the Processing editor, so where you put that data directory depends on how your code is setup. And you haven't posted a MCVE, so it's hard to help you with that.
But basically, you need to debug your sketch to figure out exactly where Processing is looking for the files. Then you need to move the files there. This is probably something simple like putting them inside a data directory.
If you still can't get it working, please post a MCVE along with a screenshot or a description of your directory structure.
If you are using the processing IDE than the data folder should be located in your sketch folder next to all the .pde files. Make sure that the image you are using has the same resolution as the sketch window. If you are still having issues I would recommend that you try moving your setup and draw methods out of your class and into the main processing sketch.
I have the following Java Applet, which makes a simple sound:
import java.applet.*;
import java.awt.Graphics;
import java.net.MalformedURLException;
import java.net.URL;
public class Sound extends Applet {
AudioClip soundFile1;
public void init() {
soundFile1 = getAudioClip(getDocumentBase(),"collectgarments_alreadyassigned.wav");
soundFile1.play();
}
}
I want to use this applet in an HTML page, which is inside a .net project. I want it to be deployed eg make its sound onClick, so am trying to create a JavaScript method to play the sound.
So far I have the following:
function Sound() {
var attributes = { id:'SoundApplet', code:'Sound.class', archive:'Java/Sound.jar', width:0, height:0} ;
var parameters = { permissions:'sandbox'} ;
deployJava.runApplet(attributes, parameters, '1.6');
}
This method makes the sound, but it also makes all the HTML disappear on the screen.
Possible reasons for this I can think of are that the Applet is trying to rewrite all the HTML on the page but is not being given any HTML to write?
If so a possible solution could be to include it in a div in a similar way to a div set to `display="none"', but I would not know how to do that as this is a sound not a visual aspect.
Maybe my thoughts are completely wrong and it is something else altogether.
I cannot find anything relevant on the internet and the internet explorer debugger is no help either.
Anyone else come across this problem??
I have found the answer myself. I do not know the reasons that this works, but it does:
function Sound()
{
var app = document.createElement('applet');
app.id= 'SoundApplet';
app.archive= 'Java/Sound.jar';
app.code= 'Sound.class';
app.width = '0';
app.height = '0';
document.getElementsByTagName('body')[0].appendChild(app);
}
Okay, I understand your need for an SSCCE, so I created (my first) one.
I managed to replicate the problem with under 200 lines of code. On my system this demo compiled and ran perfectly (only the flickering was still there of course).
I stripped everything that had nothing to do with it. So basically we have two source files now: the screen manager and the game manager.
The screen manager:
http://pastebin.com/WeKpxEXW
The game manager:
http://pastebin.com/p3C5m8UN
You can compile this code with this make file (I use a ported version of Linux' make for Windows):
CC = javac
BASE = nl/jorikoolstra/jLevel
CLASS_FILES = classes/$(BASE)/Game/GameMain.class classes/$(BASE)/Graphics/ScreenManager.class
jLevel: $(CLASS_FILES)
#echo Done.
classes/%.class : src/%.java
#echo Compiling src/$*.java to $# [command: $(CC) src/$*.java ] ...
#$(CC) -Xlint:unchecked -d classes -classpath src src/$*.java
Where the source files are placed in the /src directory and the classes in the /classes directory.
After compilation to byte-code the game can be started using the following .bat file:
#set STARUP_CLASS=nl.jorikoolstra.jLevel.Game.GameMain
#set ARGUMENTS=1280 1024 32
#java -cp classes;resources %STARUP_CLASS% %ARGUMENTS%
Note that the ARGUMENT variable depends on your own screen settings and that you have to change it so that the game is displayed in the right resolution for your screen.
I see why it is flickering ----
BufferStrategy is doing a separate painting job from the Component's paint() method and they seem to use different Graphics objects and they are refreshing at a different rate --
when paint() is invoked before show(), it's fine. But
when paint() is invoked after show(), it will repaint the component to its initial blank look -- so flashing happens.
It's very easy to eliminate the flickering: override paint() method of your JFrame (GameMain) as you don't need it to do anything (BufferStrategy can give you more precise control on painting stuffs):
#Override
public void paint (Graphics g) {}
That's all. (I have tested it and it works fine, hope this may help :))
===== Update =====
Instead of overriding paint() method, a better way is to call setIgnoreRepaint(true) for your JFrame (GameMain) -- this method is just designed for such purposes! USE IT!
private GameMain(String ... args)
{
setIgnoreRepaint(true);
.....
}
This is how i implement double buffering, might help you get the concept.
Note it's implemented in a JPanel, but i think it can be implemented in other containers:
TheJApplet.java:
import java.awt.*;
import javax.swing.*;
public class TheJApplet extends JApplet
{
private Image myImage;
java.net.URL GameURL = CheckerGameJApplet.class.getResource("GameIMG");
String GamePath = GameURL.getPath();
#Override
public void init()
{
String GraphPath = GamePath+"/";
File myImage_File = new File(GraphPath+"myImage.jpg");
try
{
myImage = ImageIO.read(myImage_File);
}
catch (IOException ex)
{
// Add how you like to catch the IOExeption
}
final TheJPanel myJPanel = new TheJPanel(myImage);
add(myJPanel);
}
}
TheJPanel.java:
import java.awt.*;
import javax.swing.*;
public class TheJPanel extends JPanel
{
private int screenWidth = 500;
private int screenHeight = 500;
private BufferedImage BuffImg = new BufferedImage
(screenWidth,
screenHeight,
BufferedImage.TYPE_INT_RGB);
private Graphics2D Graph = BuffImg.createGraphics();
private Image myImage;
public TheJPanel(Image myImage)
{
this.myImage = myImage;
repaint();
}
#Override
public void paintComponent(Graphics G)
{
Graphics2D Graph2D = (Graphics2D)G;
super.paintComponent(Graph2D);
if(BuffImg == null)
{
System.err.println("BuffImg is null");
}
Graph.drawImage(myImage, 0, 0, this);
Graph2D.drawImage(BuffImg, 0, 0, this);
}
}
Hope this helps, good luck.
I have a cross-platform Java AWT-based program with animation. It had flashing problems until I strictly followed the example code at in the Java BufferStrategy documentation. However I'm using an AWT Canvas embedded in a Swing hierarchy, not full screen as you. You can see the code here if interested.
Another thing to note is that the AWT pipeline uses OpenGL primitives for good performance, and OpenGL support is buggy in many video drivers. Try installing latest versions of drivers for your platform.
It may work for you, when you set your hwnd.createBufferStrategy(2) in its own method.
There was a problem with Java rendering transparent background GIF images. That could be the problem.
I find it rather difficult to answer your question without an SCCSE. I also wonder what the RepaintManagerResetter does.
You might want to set your background color to some fancy colors like 0xFF00FF to find out if someone "clears" the background before the drawing happens. If the flicker image is purple, it's that - if it contains garbage or old images, it's probably the double-buffering.
In any case I would try to ensure that noone draws expect yourself. First, try to prevent native Windows code from drawing the window background. Set this once:
/*
* Set a Windows specific AWT property that prevents heavyweight components
* from erasing their background.
*/
System.setProperty("sun.awt.noerasebackground", "true");
Also, make sure that you override this in your JFrame(if you are using Swing components)
#Override
public void paintComponent(Graphics G)
{
// do not call super.pC() here
...
}
If that doesn't help, please provide a working example of your code, so people can reproduce the problem.
I am getting the java.lang.SecurityException: Permission denied: file:////Videos/public/scripts/screenshot.jar when I try to use an applet.
Here is the applet code:
<applet code="Screenshot" archive="file:////Videos/public/scripts/screenshot.jar" width="100px" height="100px">
</applet>
How do I fix it and what the problem even means?
EDIT:
From what I see I need to sign the applet. Could some one explain how and why this is done? The site provided does a bad job explaining it because it doesn't even address the fact that I am embedding this into my site and want every client to use it and not have to sign anything. Just click run.
EDIT2:
The code of the app itself:
/*
By Bavo Bruylandt (Http://www.realapplets.com")
*/
// and now The inevidable "Hello World" example :)
// tell the compiler where to find the methods you will use.
// required when you create an applet
import java.applet.*;
// required to paint on screen
import java.awt.*;
// the start of an applet - HelloWorld will be the executable class
// Extends applet means that you will build the code on the standard Applet class
public class Screenshot extends Applet
{
// The method that will be automatically called when the applet is started
public void init()
{
// It is required but does not need anything.
}
// This method gets called when the applet is terminated
// That's when the user goes to another page or exits the browser.
public void stop()
{
// no actions needed here now.
}
// The standard method that you have to use to paint things on screen
// This overrides the empty Applet method, you can't called it "display" for example.
public void paint(Graphics g)
{
//method to draw text on screen
// String first, then x and y coordinate.
g.drawString("Hey hey hey",20,20);
g.drawString("Hellooow World",20,40);
}
}
It all depends on what is your applet trying to do, is it accessing the filesystem for example. Is it a signed applet or not? Applets run in a special sandbox by default with limited permissions.
You would have to check out more info on Applet security, for starters have a look into Informit article here: http://www.informit.com/articles/article.aspx?p=433382&seqNum=2
EDIT:
Try to add a policy file eg.
/* AUTOMATICALLY GENERATED ON Tue Apr 16 17:20:59 EDT 2002*/
/* DO NOT EDIT */
grant {
permission java.security.AllPermission;
};
named eg. java.policy.applet and place it on your classpath. Have a look at this question here about the policy files: Where to place java applet policy file?
I made this pacman game using an applet. When the applet finishes loading, it is meant to display a 'start menu' graphic i made which says 'Double click to start the game', etc. The graphic would take up the whole 400x400 applet. Here's the code:
public void paint(Graphics g)
{
if (! isRunning)
{
switch (result)
{
case 0:
showStartScreen(g);
break;
case 1:
showWonScreen(g);
break;
case -1:
showLostScreen(g);
break;
}
return;
}
//Code for rendering other stuff if game is here
}
showStartScreen:
public void showStartScreen(Graphics g)
{
Image intro=img.getImg("pacman-intro.png");
g.drawImage(intro, 0, 0, this);
}
This works fine when I run this locally on Eclipse, but in the web browser, when the applet is loaded I just see a blank box where the java's loading animation previously was. Surprisingly, if I double click randomly where the applet is meant to be, the game starts and works as normal. So this makes me think that the problem is just with drawing .png files using drawImage.
The same thing occurs when you win or lose the game,it just hangs instead of drawing the graphic it needs to.
You can see this here (you can use arrow keys to control)
P.S I am using double buffering here.
Any thoughts..?
EDIT: Code for ImgHelper class which is used to load the img:
import java.awt.Image;
import java.net.URL;
import javax.swing.ImageIcon;
public class ImgHelper
{
public Image getImg(String file)
{
//Engine is the name of the base applet class
URL url=Engine.class.getClassLoader().getResource("assets/" + file);
return new ImageIcon(url).getImage();
}
}
Ah, I checked the contents of your jar file.
Replace "pacman-intro.png" with "pacman-intro.PNG". It's case-sensitive.
Are the pngs in the right directory? Is "." in the path env-variable on the server?
Try "./pacman-intro.png" i.e.