import java.io.*;
import java.nio.file.*;
import java.util.stream.*;
import java.util.regex.*;

public class FileComparison {
    public static void main(String[] args) throws IOException {
        Path file1Path = Paths.get("File1.txt");
        Path file2Path = Paths.get("File2.txt");

        // Use process method below to remove random text 
        // between your static bounded text 
        List<String> file1Lines = processFile(file1Path);
        List<String> file2Lines = processFile(file2Path);

        // Now you can compare file1Lines and file2Lines

    }

    // This method will identify pattern and replace the random text
    // identified by regex with a constant value
    private static List<String> processFile(Path filePath) throws IOException {
        Pattern pattern = Pattern.compile("XYZ.*?ZYX");
        return Files.lines(filePath)
            .map(line -> {
                Matcher matcher = pattern.matcher(line);
                return matcher.replaceAll("XYZIGNOREZYX");
            })
            .collect(Collectors.toList());
    }
}

字符串
正则表达式模式.*?匹配任意数量的任意字符，但尽可能少地匹配（这称为非贪婪匹配-使用此链接了解更多信息）。
这对于正确处理包含多个“XYZ... ZYX”模式的行是必要的。
replaceAll方法将正则表达式的所有匹配项替换为“XYZIGNOREZYX”