In this post I will show you how to read and write data types in simple xml file format using XML DOM. DOM means Document Object Model. We are mainly concerned here with reading and writing some data of the same types we have been working with in previous articles. So i.e. XML document can be more complex with other parts to parse. In this we have a document root which has as it children which has as its children has attributes which contain the data we want to store. But also text data can be stored if we use text </some data> notation. The way this works we load the entire xml file into xml DOM document object. The we use methods to access the nodes in the DOM Tree. If you do not understand this terminology then research data structures and tree structures. The name=value pair is c...
Reading and Writing Objects to files or streams is fairly straight forward. Here is a working example. There are a few things to know. Use serialver.exe to create a serial id number for the class. A class must implement Serializable interface and should use @serial tag in Javadoc comments. A cryptic coded file is created which is not very editable or readable. In a later article I will talk about serializing objects to xml streams and files.
This article demonstrates using a fixed field width | delimited text file similar to a spread sheet. You can store and retrieve various data types in give row,col cells. It expands columns if new data is longer than the cell. It does not add new columns or rows however and if you try to access columns or rows that are no there you get out of bounds errors. In the example I show a survey note book sheet that we use in mapping caves. A future version of this might calculate variables that would be used in cave mapping and add them to the sheet. This could also be used for mapping things above ground.
I show you how to read and write your own property file which contains name=value pairs. Java comes with a Properties object to do this exact thing and I will write an article about that object later. Or expand this article to include an example. This article is another example of using a delimiter and in this case it is = symbol. Later I will upgrade this to include new line as delimiter to handle long strings.
Here I show you how to read and write | delimited files. Each column is a field in a record. If you are writing simple applications or prototyping why use a full database? This can work just as well. I show you how to convert data types to strings and strings back to basic datatypes.
Simple examples for writing and reading to and from a text file line by line. Write, Read and Append. In Java we not only use FileWriter and FileReader but also BufferedWriter and BufferedReader to speed up reading and writing in just about all cases.
RSS feed is http://arksoft.libsyn.com/rss I talk about books that I have been reading. I discuss techniques and concepts related to 3D game programming using Java. Though much of this content is about game development in general and only a small part is directly about Java or exact coding. Books that I talk about.. Black Art of Java Game Programming Black Art of 3D Game Programming C Building a 3D Game Engine C++ I talk about.. Isometric Parallel Orthogonal view World Perspective view Rendering Pipeline Texture Mapping Shading Lighting Other effects Culling for efficiency Painters algorithm for removing hidden objects. Culling for removing hidden objects Z buffer and Z order Other culling methods Collision Detection and efficiency And other stuff.
RSS feed is http://arksoft.libsyn.com/rss I talk about books that I have been reading. I discuss techniques and concepts related to 2D game programming using Java. Though much of this content is about game development in general and only a small part is directly about Java or exact coding. Books that I talk about.. Black Art of Java Game Programming Black Art of 3D Game Programming C Building a 3D Game Engine C++ Fundamentals of 2D Game Programming with Java As far as techniques go, there is too much to list, but here are a few. What Matrix math is used for.. What Vector math is used for.. Screens Scrolling Collision Detection Images and Sprites Animation Turn Based vs Real Time Sound And more.
RSS feed is http://arksoft.libsyn.com/rss On this one I tell you about my open source projects.. Java Reference Java White Board Java Cave Maps Java Games and Graphics Java Quiz Java Ledger Java Heat Wave Open Text Reader I talk about my experience thus far with open source and open source developers. I tell you about what has been accomplished thus far. Decisions I've made good or bad and upcoming changes. I tell you about the new feature on Arksoft.org broadcasting my coding sessions or giving live classes.
I show you how to find the dox console, or windows shell, or command line. I show you how to find and use the Java Control Panel. I show you how to add a trusted site. I show you how to write and applet and view it with both applet viewer and Windows Internet Explorer from the local hard drive or localhost. I also show you a little about a Java game Free Colonization. http://freecol.org
RSS feed is http://arksoft.libsyn.com/rss Other types of classes, Error assert keyword and AssertionError can turn off with compiler option debugging using System.out.println(); serializable keyword Also need to explain that you do not have to extend an abstract class to use its static members. Also its a compile time error to try to have a abstract static method or member. explain java arrays, no 2 dimentioned arrays, only arrays of arrays java, javax, and org java applet applet is a java.awt.Panel start, stop, init, destroy methods to play sound methods for loading images other utility type methods awt Canvas,Panel, Frame, Button, Menu, Edit Box etc. Layout management classes Image processing classes Color classes Windows event handling classes for mouse and key events and window events....