INSIDE THE HEATON RESEARCH SPIDER - HTTP Programming Recipes for Java Bots - page 460

if (field.getType() == String.class) {
field.set(this, value);
} else if (field.getType() == List.class) {
List<String> list = (List<String>) field.get(this);
list.add(value);
} else {
int x = Integer.parseInt(value);
field.set(this, x);
}
}
}
The load and loadLine methods of the SpiderOptions class are used to
load data from a spider configuration file. The load method works by reading a simple
configuration file that consists of name value pairs. For each name that is found in the file,
the loadLine method uses Java reflection to determine how to set the variable in a
SpiderOptions object. This allows us to quickly add new variables by adding them
to the SpiderOptions object. No additional parsing code is needed for any new prop-
erty.
Reading a Configuration File
The load method reads the spider configuration file. For each line encountered by the
load method, the loadLine method is called. The load method begins by opening the
file and creating a BufferedReader . The BufferedReader will allow us to read
the file on a line-by-line basis.
FileReader f = new FileReader(new File(inputFile));
BufferedReader r = new BufferedReader(f);
Next, a single line is read from the file. If the line is null , then the program is done
reading the file.
String line;
while ((line = r.readLine()) != null) {
The line that was read is passed on to the parseLine method. Any exceptions that
can occur are thrown as a SpiderException .
try {
parseLine(line);
} catch (IllegalArgumentException e) {
throw (new SpiderException(e));
} catch (SecurityException e) {
throw (new SpiderException(e));
} catch (IllegalAccessException e) {
throw (new SpiderException(e));
} catch (NoSuchFieldException e) {
throw (new SpiderException(e));