utility.java

MoMEUnit是一个单元测试的J2ME的应用程序xUnit架构实例。这是来自JUnit框架

package org.momeunit.ant.core;

import java.io.File;
import java.text.NumberFormat;
import java.util.Random;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Task;
import org.momeunit.ant.taskdefs.EmptyAttributeException;

/**
 * Collection of static utility methods.
 * 
 * @author Sergio Morozov
 * @version 1.1.2
 */
public class Utility
{

  private static final NumberFormat timeFormatter = NumberFormat
      .getNumberInstance();
  static
  {
    timeFormatter.setMaximumFractionDigits(6);
    timeFormatter.setGroupingUsed(false);
  }

  /**
   * Prohibits instantiation.
   * 
   * @since 1.1
   */
  protected Utility()
  {
    super();
  }

  /**
   * New line character.
   * 
   * @since 1.1
   */
  public static final String NEWLINE = System.getProperty("line.separator");

  /**
   * Asserts that given file is an existent directory.
   * 
   * @param dir
   *          file to test.
   * @throws BuildException
   *           if given file is not an existent directory.
   * @since 1.1
   */
  public static void assertDirectory(File dir)
  {
    assertDirectory(dir, null);
  }

  /**
   * Asserts that given file is an existent directory.
   * 
   * @param dir
   *          file to test.
   * @param type
   *          type of directory: string prepended to error message.
   * @throws BuildException
   *           if given file is not an existent directory.
   * @since 1.1
   */
  public static void assertDirectory(File dir, String type)
  {
    if (dir == null || !dir.exists() || !dir.isDirectory()) throw new BuildException(
        (type != null ? type + " " : "")
            + (dir != null ? dir.getAbsolutePath() : "unknown")
            + " is not a directory.");
  }

  /**
   * Asserts that given file exists.
   * 
   * @param file
   *          file to test.
   * @param type
   *          type of file: string prepended to error message.
   * @throws BuildException
   *           if given file doesn't exist.
   * @since 1.1
   */
  public static void assertExists(File file, String type)
  {
    if (file == null || !file.exists()) throw new BuildException(
        (type != null ? type + " " : "")
            + (file != null ? file.getAbsolutePath() : "unknown")
            + " does not exist.");
  }

  /**
   * Asserts that given file exists.
   * 
   * @param file
   *          file to test.
   * @throws BuildException
   *           if given file doesn't exist.
   * @since 1.1
   */
  public static void assertExists(File file)
  {
    assertExists(file, null);
  }

  /**
   * Asserts that given file is a regular file.
   * 
   * @param file
   *          file to test.
   * @param type
   *          type of file: string prepended to error message.
   * @throws BuildException
   *           if given file is not a regular file.
   * @since 1.1
   */
  public static void assertFile(File file, String type)
  {
    if (file == null || !file.exists() || !file.isFile()) throw new BuildException(
        (type != null ? type + " " : "")
            + (file != null ? file.getAbsolutePath() : "unknown")
            + " is not an existent file.");
  }

  /**
   * Asserts that given file is a regular file.
   * 
   * @param file
   *          file to test.
   * @throws BuildException
   *           if given file is not a regular file.
   * @since 1.1
   */
  public static void assertFile(File file)
  {
    assertFile(file, null);
  }

  /**
   * Asserts that given attribute is not empty.
   * 
   * @param attr
   *          value of attribute to test.
   * @param attrName
   *          name of attribute to test.
   * @param elName
   *          name of element containing an attribute.
   * @throws BuildException
   *           if given attribute is empty.
   * @since 1.1
   */
  public static void assertNotEmpty(String attr, String attrName, String elName)
  {
    if (attr == null || attr.length() == 0) throw new EmptyAttributeException(
        attrName, elName);
  }

  /**
   * Asserts that required attribute is set.
   * 
   * @param attr
   *          value of attribute to test.
   * @param attrName
   *          name of attribute to test.
   * @param elName
   *          name of element containing an attribute.
   * @throws BuildException
   *           if given attribute is empty.
   * @since 1.1
   */
  public static void assertRequiredAttribute(Object attr, String attrName,
      String elName)
  {
    if (attr == null) throw new BuildException(
        "Unspecified required attribute " + attrName + " of <" + elName + ">");
  }

  /**
   * Formats time specified as double value of seconds.
   * 
   * @param time
   *          seconds as double value.
   * @return formatted string.
   * @since 1.1
   */
  public static String formatTime(double time)
  {
    return timeFormatter.format(time);
  }

  /**
   * <p>
   * Parses given string. Returns the time interval as number of milliseconds or
   * <code>-1</code> if parse error occurs. String must be of the form:
   * </p>
   * <code> &lt;DoubleLiteral&gt;[&lt;UnitSuffix&gt;]</code>
   * <p>
   * <code>DoubleLiteral</code> is double number string representation as
   * specified by {@link Double#valueOf(String)}.
   * </p>
   * <p>
   * <code>UnitSuffix</code> is an optional specification of unit of time. It
   * can be one of the following
   * <ul>
   * <li><code>h</code> - for hours;</li>
   * <li><code>m</code> - for minutes;</li>
   * <li><code>s</code> - for seconds;</li>
   * <li><code>ms</code> - for milliseconds.</li>
   * </ul>
   * If omitted milliseconds are implied. <code>UnitSuffix</code> is case
   * insensitive (<code>ms</code>, <code>MS</code>, <code>Ms</code>,
   * <code>mS</code> mean the same).
   * </p>
   * 
   * @param timeInterval
   *          string representing time interval.
   * @return the time interval in milliseconds or <code>-1</code> if string is
   *         not parsable.
   * @since 1.1.1
   */
  public static long parseTimeInterval(String timeInterval)
  {
    long res = -1;
    if (timeInterval != null)
    {
      int m = 1;
      int lastCharPos = timeInterval.length() - 1;
      char lastChar = timeInterval.charAt(lastCharPos);
      switch (lastChar)
      {
      case 'S':
      case 's':
        m = 1000;
        if (lastCharPos > 0
            && (timeInterval.charAt(lastCharPos - 1) == 'M' || timeInterval
                .charAt(lastCharPos - 1) == 'm'))
        {
          m = 1;
          lastCharPos--;
        }
        break;
      case 'M':
      case 'm':
        m = 60000;
        break;
      case 'H':
      case 'h':
        m = 3600000;
        break;

      default:
        lastCharPos++;
        break;
      }
      try
      {
        res = (int) (Double.parseDouble(timeInterval.substring(0, lastCharPos)) * m);
      } catch (Throwable e)
      {}
    }
    return res;
  }

  /**
   * Logs specified <code>message</code> using given <code>project</code> if
   * <code>project</code> is not <code>null</code>. Does nothing if
   * <code>project</code> is <code>null</code>.
   * 
   * @param project
   *          project that logs the message.
   * @param message
   *          message to log.
   * @since 1.1
   */
  public static void log(Project project, String message)
  {
    if (project != null) project.log(message);
  }

  /**
   * Logs specified <code>message</code> using given <code>project</code>
   * and <code>priority</code> if <code>project</code> is not
   * <code>null</code>. Does nothing if <code>project</code> is
   * <code>null</code>.
   * 
   * @param project
   *          project that logs the message.
   * @param message
   *          message to log.
   * @param priority
   *          priority with which to log the message.
   * @since 1.1
   */
  public static void log(Project project, String message, int priority)
  {
    if (project != null) project.log(message, priority);
  }

  /**
   * Logs specified <code>message</code> using given <code>task</code> if
   * <code>task</code> is not <code>null</code>. Does nothing if
   * <code>task</code> is <code>null</code>.
   * 
   * @param task
   *          task that logs the message.
   * @param message
   *          message to log.
   * @since 1.1
   */
  public static void log(Task task, String message)
  {
    if (task != null) task.log(message);
  }

  /**
   * Logs specified <code>message</code> using given <code>task</code> and
   * <code>priority</code> if <code>task</code> is not <code>null</code>.
   * Does nothing if <code>task</code> is <code>null</code>.
   * 
   * @param task
   *          task that logs the message.
   * @param message
   *          message to log.
   * @param priority
   *          priority with which to log the message.
   * @since 1.1
   */
  public static void log(Task task, String message, int priority)
  {
    if (task != null) task.log(message, priority);
  }

  /**
   * Creates and returns unique directory with name composed of specified prefix
   * and random numeric part not greater than given value. Directory is created
   * in specified <code>parent</code> directory.
   * 
   * @param parent
   *          parent directory to create directory in. If <code>null</code>
   *          current directory is used.
   * @param prefix
   *          prefix of created directory.
   * @param maxNumber
   *          maximum value of random numeric part. For example
   *          <code>99999</code> for five characters long random part.
   * @return created directory.
   * @throws BuildException
   *           if an error occurred during directory creation.
   * @since 1.1.2
   */
  public static File createUniqueDirectory(File parent, String prefix,
      int maxNumber)
  {
    File dir = null;
    for (Random random = new Random(); dir == null || dir.exists(); dir = new File(
        parent, prefix + random.nextInt(maxNumber)));
    if (!dir.mkdir()) throw new BuildException("Error creating directory "
        + dir.getAbsolutePath());
    return dir;
  }
}