FileUtils.java

package org.teachingextensions.approvals.lite.util.io;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileFilter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;

import org.teachingextensions.approvals.lite.util.ArrayUtils;
import org.teachingextensions.approvals.lite.util.Asserts;
import org.teachingextensions.approvals.lite.util.ObjectUtils;

/**
 * A static class of convenience functions for Files
 */
public class FileUtils
{
  public static String readFromClassPath(Class<?> clazz, String string)
  {
    final InputStream resourceAsStream = loadInputStream(clazz, string);
    return FileUtils.readStream(resourceAsStream);
  }
  public static InputStream loadInputStream(Class<?> type, String name)
  {
    InputStream resource = type.getResourceAsStream(name);
    if (resource == null)
    {
      resource = type.getClassLoader().getResourceAsStream(name);
    }
    if (resource == null) { throw new IllegalStateException("Could not find resource: " + name); }
    return resource;
  }
  public static File[] getRecursiveFileList(File directory)
  {
    return getRecursiveFileList(directory, new SimpleFileFilter());
  }
  public static File[] getRecursiveFileList(File directory, FileFilter filter)
  {
    ArrayList<File> list = new ArrayList<>();
    if (!directory.isDirectory()) { throw new Error("File is not a directory: " + directory.getName()); }
    File directories[] = directory.listFiles(new SimpleDirectoryFilter());
    for (File directory1 : directories)
    {
      ArrayUtils.addArray(list, getRecursiveFileList(directory1, filter));
    }
    File files[] = directory.listFiles(filter);
    ArrayUtils.addArray(list, files);
    return list.toArray(new File[list.size()]);
  }
  public static void writeFile(File file, String text) throws IOException
  {
    Asserts.assertNotNull("Writing to file: " + file, text);
    File canonicalFile = file.getCanonicalFile();
    canonicalFile.getParentFile().mkdirs();
    BufferedWriter out = new BufferedWriter(new FileWriter(file));
    out.write(text);
    out.close();
  }
  public static void writeFileQuietly(File file, String text)
  {
    try
    {
      writeFile(file, text);
    }
    catch (IOException e)
    {
      ObjectUtils.throwAsError(e);
    }
  }
  public static String readFile(String absolutePath) throws IOException
  {
    return readFile(new File(absolutePath));
  }
  public static String readFile(File file) throws IOException
  {
    BufferedReader in = new BufferedReader(new FileReader(file));
    return readBuffer(in);
  }
  public static String readBuffer(BufferedReader in) throws IOException
  {
    StringBuilder string = new StringBuilder();
    while (in.ready())
    {
      string.append(in.readLine());
      string.append("\n");
    }
    in.close();
    return string.toString();
  }
  public static String readFileWithSuppressedExceptions(File databaseFile)
  {
    try
    {
      return FileUtils.readFile(databaseFile);
    }
    catch (FileNotFoundException e)
    {
      throw new RuntimeException("Invalid file '" + databaseFile.getAbsolutePath() + "'", e);
    }
    catch (IOException e)
    {
      throw new RuntimeException(e);
    }
  }
  public static String getExtensionWithDot(String filename)
  {
    int p = filename.lastIndexOf('.');
    return filename.substring(p);
  }
  public static void createIfNeeded(String file) throws IOException
  {
    File f = new File(file);
    if (!f.exists())
    {
      writeFile(f, "");
    }
  }
  public static String readStream(InputStream resourceAsStream)
  {
    BufferedReader reader = new BufferedReader(new InputStreamReader(resourceAsStream));
    String resource = null;
    try
    {
      resource = FileUtils.readBuffer(reader);
    }
    catch (IOException e)
    {
      ObjectUtils.throwAsError(e);
    }
    return resource;
  }
  public static boolean isNonEmptyFile(String approved)
  {
    File file = new File(approved);
    return file.exists() && file.length() > 0;
  }
}