Do more complex search by using FileVisitor - Java File Path IO

Java examples for File Path IO:Directory Search

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Description

Do more complex search by using FileVisitor

Demo Code

import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.FileVisitOption;
import java.nio.file.FileVisitResult;
import java.nio.file.FileVisitor;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.PathMatcher;
import java.nio.file.Paths;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.EnumSet;

public class Main {
  public static void main(String[] args) throws Exception {
    String glob = "*.jpg";
    long size = 102400; // 100 kilobytes in bytes
    Path fileTree = Paths.get("C:/folder1/");
    Search walk = new Search(glob, size);
    EnumSet opts = EnumSet.of(FileVisitOption.FOLLOW_LINKS);

    Files.walkFileTree(fileTree, opts, Integer.MAX_VALUE, walk);

  }/* w  w  w  .j av  a2 s  .  c om*/
}

class Search implements FileVisitor {

  private final PathMatcher matcher;
  private final long accepted_size;

  public Search(String glob, long accepted_size) {
    matcher = FileSystems.getDefault().getPathMatcher("glob:" + glob);
    this.accepted_size = accepted_size;
  }

  void search(Path file) throws IOException {
    Path name = file.getFileName();

    long size = (Long) Files.getAttribute(file, "basic:size");

    if (name != null && matcher.matches(name) && size <= accepted_size) {
      System.out.println("Searched file was found: " + name + " in "
          + file.toRealPath().toString() + " size (bytes):" + size);
    }
  }

  @Override
  public FileVisitResult postVisitDirectory(Object dir, IOException exc)
      throws IOException {
    System.out.println("Visited: " + (Path) dir);
    return FileVisitResult.CONTINUE;
  }

  @Override
  public FileVisitResult preVisitDirectory(Object dir, BasicFileAttributes attrs)
      throws IOException {
    return FileVisitResult.CONTINUE;
  }

  @Override
  public FileVisitResult visitFile(Object file, BasicFileAttributes attrs)
      throws IOException {
    search((Path) file);
    return FileVisitResult.CONTINUE;
  }

  @Override
  public FileVisitResult visitFileFailed(Object file, IOException exc)
      throws IOException {
    // report an error if necessary
    return FileVisitResult.CONTINUE;
  }
}

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