FileManagementUtils.java

package se.chalmers.gdcn.files;

import se.chalmers.gdcn.taskbuilder.fileManagement.PathManager;

import java.io.*;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by HalfLeif on 2014-04-02.
 */
public class FileManagementUtils {

    /**
     * Outputs some arbitrary data to file on disk
     *
     * @param file File to turn into byte[]
     * @param data contents of file
     */
    public static void toFile(File file, byte[] data){
        System.out.println("Attempt create file "+file.getAbsolutePath());
        File parent = file.getParentFile();
        parent.mkdirs();

        //TODO use Box class and do checksum, or shall we?
        BufferedOutputStream outputStream = null;
        try {
            outputStream = new BufferedOutputStream(new FileOutputStream(file));
            outputStream.write(data);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (outputStream != null) {
                try {
                    outputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    /**
     * Reads file on disk
     *
     * @param file File to read from
     * @return File contents in binary format
     * @throws IOException
     */
    public static byte[] fromFile(File file) throws IOException {

        InputStream inputStream = null;

        try {
            //TODO Possibly use MD5 instead, if SHA-1 is too slow
            MessageDigest digest = MessageDigest.getInstance("SHA-1");

            inputStream = new BufferedInputStream(new FileInputStream(file));
            DigestInputStream digestInputStream = new DigestInputStream(inputStream, digest);

            byte[] data = new byte[(int) file.length()];

            //TODO actually use digest
            digestInputStream.read(data);
            byte[] digestArray = digest.digest();

            return data;

        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } finally {
            if (inputStream != null) {
                inputStream.close();
            }
        }
        return null;
    }

    /**
     * @return Name of haskell module this taskmeta uses
     */
    public static String moduleName(TaskMeta taskMeta){
        return taskMeta.getModule().getFileName().replace(".hs", "");
    }

    public static String futureResultFilePath(PathManager pathManager, TaskMeta taskMeta){
        return pathManager.getResultFilePath(taskMeta.getTaskName());
    }

    /**
     * @param pathManager path manager
     * @param fileDep file
     * @return Absolute path to file
     */
    static File pathTo(PathManager pathManager, FileDep fileDep){
        return new File(pathManager.projectDir() + fileDep.getFileLocation() + File.separator + fileDep.getFileName());
    }

    /**
     * @return List of paths to all resource files mentioned in taskmetas
     * @param pathManager path manager
     * @param taskMeta task meta
     */
    static List<String> getResourceFiles(PathManager pathManager, TaskMeta taskMeta) {
        List<String> resources = new ArrayList<>();
        for(FileDep fileDep : taskMeta.getDependencies()){
            resources.add(pathTo(pathManager, fileDep).getAbsolutePath());
        }
        return resources;
    }
}