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How to print all the strings that match a given pattern from a file in Java
Problem Description
How to print all the strings that match a given pattern from a file?
Solution
Following example shows how to print all the strings that match a given pattern from a file with the help of Patternname.matcher() method of Util.regex class.
import java.util.regex.*; import java.io.*; public class newfile { public static void main(String[] args) throws IOException { Pattern p1 = Pattern.compile("[A-Za-z][a-z]+"); BufferedReader r = new BufferedReader(new FileReader("os.java")); String line; while ((line = r.readLine()) != null) { Matcher m = p1.matcher(line); while (m.find()) { System.out.println(m.group(0)); int s1 = m.start(0); int e1 = m.end(0); System.out.println(line.substring(s1, e1)); } } } }
Result
The above code sample will produce the following result.
Android java ios linux
java_regular_exp.htm
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