Question

How can I find and replace a word in several text files, using Java?

Here’s how I do it for a single String…

public class ReplaceAll {

    public static void main(String[] args) {
        String str = "We want replace replace word from this string";  
        str = str.replaceAll("replace", "Done");
        System.out.println(str);
    }
}

Answer 1

Using FileUtils from Commons IO:

String[] files = { "file1.txt", "file2.txt", "file3.txt" };
for (String file : files) {
    File f = new File(file);
    String content = FileUtils.readFileToString(new File("filename.txt"));
    FileUtils.writeStringToFile(f, content.replaceAll("hello", "world"));
}