package org.apache.struts.scripting;
   
   import java.io.BufferedReader;
   import java.io.IOException;
   import java.io.Reader;
   import java.nio.file.Files;
   import java.nio.file.Path;
   import java.nio.file.attribute.BasicFileAttributes;
   import java.nio.file.attribute.FileTime;
  
  /**
   * Supporter class for {@code Struts-Scripting}.
   *
   * @author Stefan Graff
   *
   * @since Struts 1.4.1
   */
  class IOUtils {
  
      private IOUtils() {}
  
      /**
       * Reads from the give {@code Path} the last modified time. If
       * the given {@code Path} is {@code null}, {@code null} will be
       * returned.
       *
       * @param path the given {@code Path}
       *
       * @return the last modified time or {@code null} if the given
       *     {@code Path} is {@code null}
       *
       * @throws IOException if an I/O error occurs
       */
      static FileTime getLastModifiedTime(final Path path) throws IOException {
          if (path == null) {
              return null;
          }
  
          BasicFileAttributes attr = Files.readAttributes(path, BasicFileAttributes.class);
          return attr.lastModifiedTime();
      }
  
      /**
       * Reads all lines from {@code Reader} and save it
       * into a {@code String}.
       *
       * @param reader the given {@code Reader}
       *
       * @return the whole text from {@code Reader}
       *
       * @throws IOException if an I/O error occurs
       */
      static String getStringFromReader(Reader reader) throws IOException {
          try (BufferedReader br = reader instanceof BufferedReader
                  ? (BufferedReader)reader
                  : new BufferedReader(reader)) {
  
              final String lineSeparator = System.lineSeparator();
              final StringBuilder sb = new StringBuilder(8 * 1024);
  
              String line;
              while ((line = br.readLine()) != null) {
                  sb.append(lineSeparator).append(line);
              }
  
              return sb.substring(sb.length() ==  0 ? 0 : lineSeparator.length());
          }
      }
  }