Pattern Matching with Regular Expressions - Java - page 156

Because the pattern may extend over more than one line, I read the entire web page from the
URL into a single long string using my FileIO.readerToString() method (see Reading a
File into a String ) instead of the more traditional line-at-a-time paradigm. I then plot a graph
using an external program (see Running an External Program from Java ) ; this could (and
should) be changed to use a Java graphics program (see Program: Grapher for some leads).
The complete program is shown in Example 4-10 .

Example 4-10. BookRank.java
public public class class BookRank BookRank {

public public final final static static String DATA_FILE = "book.sales" ;

public public final final static static String GRAPH_FILE = "book.png" ;

public public final final static static String PLOTTER_PROG = "/usr/local/bin/gnuplot" ;

final final static static String isbn = "0596007019" ;

final final static static String title = "Java Cookbook" ;

/** Grab the sales rank off the web page and log it. */
public

public static static void void main ( String [] args ) throws throws Exception {

Properties p = new new Properties ();

p . load ( new new FileInputStream (

args . length == 0 ? "bookrank.properties" : args [ 1 ]));
String title = p . getProperty ( "title" , "NO TITLE IN PROPERTIES" );
// The url must have the "isbn=" at the very end, or otherwise
// be amenable to being string-catted to, like the default.
String url = p . getProperty ( "url" , "http://test.ing/test.cgi?isbn=" );
// The 10-digit ISBN for the topic.
String isbn = p . getProperty ( "isbn" , "0000000000" );
// The RE pattern (MUST have ONE capture group for the number)
String pattern = p . getProperty ( "pattern" , "Rank: (\\d+)" );

int int rank = getBookRank ( isbn );

System . out . println ( "Rank is " + rank );

// Now try to draw the graph, using external
// plotting program against all historical data.
// Could use gnuplot, R, any other math/graph program.
// Better yet: use one of the Java plotting APIs.

PrintWriter pw = new new PrintWriter (

new new FileWriter ( DATA_FILE , true true ));

String date = new new SimpleDateFormat ( "MM dd hh mm ss yyyy " ).

format ( new new Date ());