Creating and Modifying XML Documents - Beginning Java - page 1317

// Set angle field value from a node
protected void setAngleFromXML(Node node) {
angle =
Double.valueOf(((Attr)(node.getAttributes().getNamedItem("angle"))).getValue());
}
Directory "Sketcher reading and writing XML"
The Node object that is passed to the method contains the value for angle as an attribute. Calling getAt-
tributes() for node returns all the attributes as a NamedNodeMap object. Calling getNamedItem() for this
object returns the attribute, with the name you pass as the argument, as a Node object. The getValue()
method for a Node object returns its value as a String object, so passing this to the static valueOf() method
in the Double class returns the angle value as type double .
This pattern for obtaining the value of an attribute from a Node object appears frequently. Here's how you
can initialize the position field with another method in the Element class:
// Set position field from a node
protected void setPositionFromXML(Node node) {
NamedNodeMap attrs = node.getAttributes();
position = new Point(
Integer.valueOf(((Attr)(attrs.getNamedItem("x"))).getValue()),
Integer.valueOf(((Attr)(attrs.getNamedItem("y"))).getValue()));
}
Directory "Sketcher reading and writing XML"
This method closely parallels the previous method. You extract the values for the coordinates of the point
from the attributes as integers. You then pass these to a Point class constructor.
The code to initialize the color field is very similar:
// Set color field from a node
protected void setColorFromXML(Node node) {
NamedNodeMap attrs = node.getAttributes();
color = new Color(
Integer.valueOf(((Attr)(attrs.getNamedItem("R"))).getValue()),
Integer.valueOf(((Attr)(attrs.getNamedItem("G"))).getValue()),
Integer.valueOf(((Attr)(attrs.getNamedItem("B"))).getValue()));
}
Directory "Sketcher reading and writing XML"