Reg Exp Example : Pattern « Regular Expressions « Java
- Java
- Regular Expressions
- Pattern
Reg Exp Example
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegExpExample {
public static void main(String args[]) {
String fileName = "RETestSource.java";
String unadornedClassRE = "^\\s*class (\\w+)";
String doubleIdentifierRE = "\\b(\\w+)\\s+\\1\\b";
Pattern classPattern = Pattern.compile(unadornedClassRE);
Pattern doublePattern = Pattern.compile(doubleIdentifierRE);
Matcher classMatcher, doubleMatcher;
int lineNumber = 0;
try {
BufferedReader br = new BufferedReader(new FileReader(fileName));
String line;
while ((line = br.readLine()) != null) {
lineNumber++;
classMatcher = classPattern.matcher(line);
doubleMatcher = doublePattern.matcher(line);
if (classMatcher.find()) {
System.out.println("The class [" + classMatcher.group(1)
+ "] is not public");
}
while (doubleMatcher.find()) {
System.out.println("The word \"" + doubleMatcher.group(1)
+ "\" occurs twice at position "
+ doubleMatcher.start() + " on line " + lineNumber);
}
}
} catch (IOException ioe) {
System.out.println("IOException: " + ioe);
ioe.printStackTrace();
}
}
}
Related examples in the same category
