kz.greetgo.file_storage.impl.LocalUtil Maven / Gradle / Ivy

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package kz.greetgo.file_storage.impl;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class LocalUtil {
  public static byte[] readAll(InputStream inputStream) {
    try {
      return readAllEx(inputStream);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

  public static byte[] readAllEx(InputStream inputStream) throws IOException {
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    byte[] buffer = new byte[4 * 1024];

    while (true) {
      int count = inputStream.read(buffer);
      if (count < 0) {
        return out.toByteArray();
      }
      out.write(buffer, 0, count);
    }
  }

  public static String toStrLen(int value, int len) {
    StringBuilder sb = new StringBuilder(len);
    sb.append(value);
    while (sb.length() < len) {
      sb.insert(0, '0');
    }
    return sb.toString();
  }

  public static String extractExtension(String fileName) {
    fileName = fileName.trim();
    int lastIndex = fileName.lastIndexOf('.');
    if (lastIndex < 0) {
      return null;
    }
    return fileName.substring(lastIndex + 1).toLowerCase();
  }
}