A small prototype for a switch-lights problem (four or more consecutive lights will be turned off) By Henry Chen https://henry416.wordpress.com

Exception : Numbers of source Raster bands and source color space components do not match when read image

JavaFX: Zoom all Pane Content/Children on Stage resize

JavaFX: Removing child from a Group causes Exception

Free

You can't directly modify a List while you're iterating though it. The iterator gets confused.
Do

List<Node> nodesToRemove = new ArrayList<>();
for(Node node : g.getChildren()){
    if(node instanceof Text){
        nodesToRemove.add(node);
    }
}

g.getChildren().removeAll(nodesToRemove);

or (I think):

for (Iterator<Node> iterator = g.getChildren().iterator(); iterator.hasNext();) {
    if (iterator.next() instanceof Text) {
        iterator.remove();
    }
}

or, in Java8,

g.getChildren().removeAll( g.getChildren().stream()
    .filter(node -> node instanceof Text)
    .collect(Collectors.toList()));

JavaFx Group

@DefaultProperty(value="children")
public class Group
extends Parent

• A Group node contains an ObservableList of children that are rendered in order whenever this node is rendered. A Group will take on the collective bounds of its children and is not directly resizable.

• Any transform, effect, or state applied to a Group will be applied to all children of that group. Such transforms and effects will NOT be included in this Group's layout bounds, however if transforms and effects are set directly on children of this Group, those will be included in this Group's layout bounds.

• By default, a Group will "auto-size" its managed resizable children to their preferred sizes during the layout pass to ensure that Regions and Controls are sized properly as their state changes. If an application needs to disable this auto-sizing behavior, then it should set autoSizeChildren to false and understand that if the preferred size of the children change, they will not automatically resize (so buyer beware!).

• Group Example:

    import javafx.scene.*;
    import javafx.scene.paint.*;
    import javafx.scene.shape.*;
    import java.lang.Math;

    Group g = new Group();
    for (int i = 0; i < 5; i++) {
       Rectangle r = new Rectangle();
        r.setY(i * 20);
        r.setWidth(100);
        r.setHeight(10);
        r.setFill(Color.RED);
        g.getChildren().add(r);
    }

How to get IP address in Java using InetAddress

An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication. The designers of the Internet Protocol defined an IPv4 address as a 32-bit number.

In this tutorial we are going to see how can you get the IP Address that is assigned to your own machine inside your local network and the IP Addresses assigned to specific Domain Names(e.g. www.google.com…).

To do that we are going to use InetAddress.To be more specific we are going to use:

• getLocalHost().getHostAddress() method of InetAddress to get the IP Address of our machine in our local network
• getByName() method of InetAddress to get the IP Address of a specific Domain Name
• getAllByName() method of InetAddress to get all the IP Address of a specific Domain Name.

How to print all the Java system properties

The other day, when I was trying to compile all the Tame Swing examples, I had a problem running one of the examples. The problem was that I was running the example in Eclipse, and I was getting an error message showing the Eclipse (the JVM really) couldn't find the icon image files.

I thought I had everything configured properly, but still I kept getting the same error message. Finally I decided to look at my Java system properties and see what my build path really looked like. I couldn't think of the right Java property to show the build path, so instead of trying to print just the one Java property, I decided to print all the Java properties, then dig through them manually. You print Java system properties with the System.getProperties() method.

Here's the code I used to print all the Java system properties:

Properties p = System.getProperties(); Enumeration keys = p.keys(); while (keys.hasMoreElements()) {   String key = (String)keys.nextElement();   String value = (String)p.get(key);   System.out.println(key + ": " + value); }

And here's the output from that section of code:

java.runtime.name: Java(TM) 2 Runtime Environment, Standard Edition
sun.boot.library.path: /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Libraries
java.vm.version: 1.5.0_07-87
awt.nativeDoubleBuffering: true
gopherProxySet: false
java.vm.vendor: "Apple Computer, Inc."
java.vendor.url: http://apple.com/
path.separator: :
java.vm.name: Java HotSpot(TM) Client VM
file.encoding.pkg: sun.io
user.country: US
sun.os.patch.level: unknown
java.vm.specification.name: Java Virtual Machine Specification
user.dir: /Users/al/DD/Projects/TameSwing
java.runtime.version: 1.5.0_07-164
java.awt.graphicsenv: apple.awt.CGraphicsEnvironment
java.endorsed.dirs: /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Home/lib/endorsed
os.arch: i386
java.io.tmpdir: /tmp
line.separator: 

java.vm.specification.vendor: Sun Microsystems Inc.
os.name: Mac OS X
sun.jnu.encoding: MacRoman
java.library.path: .:/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java
java.specification.name: Java Platform API Specification
java.class.version: 49.0
sun.management.compiler: HotSpot Client Compiler
os.version: 10.4.10
user.home: /Users/al
user.timezone: 
java.awt.printerjob: apple.awt.CPrinterJob
file.encoding: MacRoman
java.specification.version: 1.5
java.class.path: /Users/al/DD/Projects/TameSwing/bin:/System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/.compatibility/14compatibility.jar
user.name: al
apple.awt.graphics.UseQuartz: true
java.vm.specification.version: 1.0
java.home: /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Home
sun.arch.data.model: 32
user.language: en
java.specification.vendor: Sun Microsystems Inc.
awt.toolkit: apple.awt.CToolkit
java.vm.info: mixed mode, sharing
java.version: 1.5.0_07
java.ext.dirs: /Library/Java/Extensions:/System/Library/Java/Extensions:/System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Home/lib/ext
sun.boot.class.path: /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/classes.jar:/System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/ui.jar:/System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/laf.jar:/System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/sunrsasign.jar:/System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/jsse.jar:/System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/jce.jar:/System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/charsets.jar
java.vendor: Apple Computer, Inc.
file.separator: /
java.vendor.url.bug: http://developer.apple.com/java/
sun.io.unicode.encoding: UnicodeLittle
sun.cpu.endian: little
mrj.version: 1040.1.5.0_07-164
sun.awt.exception.handler: apple.awt.CToolkit$EventQueueExceptionHandler
sun.cpu.isalist: