|
|
| Line 1: |
Line 1: |
| − | ==[http://www.cs.umd.edu/%7Emeesh/cmsc420/spr07/part1/p11/node20.html Using the provided XML processing code to get a working parser]==
| |
| − | === Node -> Element ===
| |
| − | <blockquote>
| |
| − | In the DOM, every XML object implements the org.w3c.dom.Node interface. Nodes have a lot of useful methods, but the ones you care most about are getNodeName(), getNodeValue(), and getAttribute(). Suppose you had a Node object representing one of our command elements. You could determine which command it was with the following code:
| |
| − | <code><pre>
| |
| − | Node command = ...;
| |
| − | if (command.getNodeName().equals("createCity"))
| |
| − | // createCity command
| |
| − | </pre></code>
| |
| − | To get the value of an attribute, you could use this code:
| |
| − | <code><pre>
| |
| − | String name = command.getAttribute("name");
| |
| − | </pre></code>
| |
| − | </blockquote>
| |
| − | If you read the Java API, you'll see both Document and Element are subtypes of Node. A Node does not have the method getAttribute(). But Element does have a getAttribute() method.
| |
| | | | |
| − | === Node Child List ===
| |
| − | <blockquote>
| |
| − | To ignore comment nodes, you can even do an instanceof check of the command node to make sure it is of type Element.
| |
| − | </blockquote>
| |
| − | instanceof checks can be costly. If there's an alternative, you should use it. That said, Node has a method called [http://java.sun.com/j2se/1.5.0/docs/api/org/w3c/dom/Node.html#getNodeType() getNodeType()].
| |
| − |
| |
| − |
| |
| − | == [http://www.cs.umd.edu/%7Emeesh/cmsc420/spr07/part1/p11/node22.html Outputting XML Conventions] ==
| |
| − |
| |
| − | === Printing to System.out ===
| |
| − | <blockquote>
| |
| − | It is sufficient to merely spit these out to System.out (the standard output stream) as they are discovered when processing the commands. However, remember that the result must be a well-formed XML document and a well-formed XML document must have a single root element.
| |
| − | </blockquote>
| |
| − | Do not call System.out.println() to print out your output. Instead, create a new Document and append Elements to it as you process commands. You can print a Document to System.out using XmlUtility.print().
| |
| − |
| |
| − | == [http://www.cs.umd.edu/%7Emeesh/cmsc420/spr07/part1/p11/node24.html Drawing a spatial map using CanvasPlus] ==
| |
| − | === Color class ===
| |
| − | It should be noted that all colors used in CanvasPlus refer to their java.awt.Color counterparts.
| |
| − |
| |
| − | == [http://www.cs.umd.edu/%7Emeesh/cmsc420/spr07/part1/p11/node26.html Input] ==
| |
| − | === spatialWidth and spatialHeight ===
| |
| − | <blockquote>
| |
| − | The attributes are spatialWidth and spatialHeight, both Unrestricted Integers...
| |
| − | </blockquote>
| |
| − | spatialWidth and spatialHeight will always be 2<sup>k</sup> by 2<sup>k</sup>. That way you can take advantage of bit operators.
| |
| − |
| |
| − | === List cities ===
| |
| − | <blockquote>
| |
| − | listCities
| |
| − | Prints all cities (vertices) currently present in the graph.
| |
| − | </blockquote>
| |
| − | Graph here means data dictionary.
| |
| − |
| |
| − | === Nearest City tie ===
| |
| − | <blockquote>
| |
| − | nearestCity
| |
| − | Will return the name and location of the closest city to the specified point in space. To do this correctly, you may want to use the PriorityQueue-otherwise, you might not be fast enough.
| |
| − | </blockquote>
| |
| − | If there is a distance tie, check the city names using java.lang.String.compareTo() (for a distance tie, the nearestCity name is less than the other city name).
| |
