logfile.java

MoMELog是J2ME的日志框架。它是非常简单的

      {
        closeConnection();
      }
  }

  /*
   * (non-Javadoc)
   * 
   * @see javax.microedition.io.file.FileSystemListener#rootChanged(int,
   *      java.lang.String)
   */
  public void rootChanged(int eventType, String root)
  {
    if (eventType == FileSystemListener.ROOT_REMOVED && this.canLog)
      this.canLog = !root.equals(this.root);
    else if (!this.canLog)
      this.canLog = root.equals(this.root);
  }

  /**
   * <p>
   * Returns {@code footer} line to be written at the end of the destination
   * file or {@code null}, if no line should be written.
   * </p>
   * <p>
   * <strong>Note:</strong> {@code footer} line is written only when
   * {@link #close()} method is called at the end of application's run (e.g.
   * from {@code MIDlet.destroyApp(boolean unconditional)} method).
   * </p>
   * 
   * @return {@code footer} line to be written at the end of the destination
   *         file or {@code null}, if no line should be written.
   */
  public String getFooter()
  {
    return this.footer;
  }

  /**
   * <p>
   * Sets {@code footer} line to be written at the end of the destination file.
   * <p>
   * <strong>Note:</strong> {@code footer} line is written only when
   * {@link #close()} method is called at the end of application's run (e.g.
   * from {@code MIDlet.destroyApp(boolean unconditional)} method).
   * </p>
   * 
   * @param footer
   *          {@code footer} line to be written at the end of the destination
   *          file or {@code null}, if no line should be written.
   */
  public synchronized void setFooter(String footer)
  {
    this.footer = footer;
  }

  /**
   * Returns {@code header} line to be written at the start of the destination
   * file or {@code null}, if no line should be written.
   * </p>
   * <p>
   * <strong>Note:</strong> {@code header} line is written only, if
   * {@link LogFile} creates or rewrites the destination file.
   * </p>
   * 
   * @return {@code header} line to be written at the start of the destination
   *         file or {@code null}, if no line should be written.
   */
  public String getHeader()
  {
    return this.header;
  }

  /**
   * Sets {@code header} line to be written at the start of the destination
   * file.
   * <p>
   * <strong>Note:</strong> {@code header} line is written only, if
   * {@link LogFile} creates or rewrites the destination file.
   * </p>
   * 
   * @param header
   *          line to be written at the start of the destination file or
   *          {@code null}, if no line should be written.
   */
  public synchronized void setHeader(String header)
  {
    this.header = header;
  }

  /**
   * Returns string to be written at the start of each logging line or
   * {@code null}, if no string should be written.
   * 
   * @return string to be written at the start of each logging line or
   *         {@code null}, if no string should be written.
   */
  public String getPrefix()
  {
    return this.prefix;
  }

  /**
   * Sets string to be written at the start of each logging line.
   * 
   * @param prefix
   *          string to be written at the start of each logging line or
   *          {@code null}, if no string should be written.
   */
  public synchronized void setPrefix(String prefix)
  {
    this.prefix = prefix;
  }

  /**
   * Returns string to be written at the end of each logging line or
   * {@code null}, if no string should be written.
   * 
   * @return string to be written at the end of each logging line or
   *         {@code null}, if no string should be written.
   */
  public String getSuffix()
  {
    return this.suffix;
  }

  /**
   * Sets string to be written at the end of each logging line.
   * 
   * @param suffix
   *          string to be written at the end of each logging line or
   *          {@code null}, if no string should be written.
   */
  public synchronized void setSuffix(String suffix)
  {
    this.suffix = suffix;
  }

  /**
   * <p>
   * Configures {@link LogFile} instance from the given character sequence.
   * Character sequence should consist of lines separated by {@code new-line}
   * character ({@code '\n'}). Each line should contain the name-value pair
   * separated by equal sign ({@code =}). Spaces around properties names are
   * allowed and ignored. Spaces around properties values are allowed.
   * </p>
   * <p>
   * {@link LogFile} supports following properties. All properties names are in
   * lower-case. If some property is specified more than one time, the last
   * occurrence prevails. <table width="100%" border="1" cellpadding="2"
   * cellspacing="0"> <col width="15%"> <col width="*"> <col width="15%">
   * <tr valign="top">
   * <td>
   * <p>
   * <strong>Property Name</strong>
   * </p>
   * </td>
   * <td>
   * <p>
   * <strong>Description</strong>
   * </p>
   * </td>
   * <td>
   * <p>
   * <strong>Default Value</strong>
   * </p>
   * </td>
   * </tr>
   * <tr>
   * <td>
   * <p align="left">
   * <strong>&quot;outfile&quot;</strong>
   * </p>
   * </td>
   * <td>
   * <p align="left">
   * Specifies the location of the destination file. It is specified as fully
   * qualified path-name, that includes starting slash ({@code /}) and root's
   * name. In other words, it is a file's url without protocol and host
   * specifiers (i.e. {@code file://}). For example file identified by url
   * {@code file:///SDCard/logs/myapp/log.txt} can be specified by path-name
   * {@code /SDCard/logs/myapp/log.txt}.
   * </p>
   * <p>
   * The default value is set to the {@code "momelog.log"} file in first root
   * returned from {@link FileSystemRegistry#listRoots()} method.
   * </p>
   * <p>
   * <strong>Note:</strong> Spaces around value of this property are ignored.
   * </p>
   * <p>
   * <em>Since version 1.0</em>
   * </p>
   * </td>
   * <td>
   * <p align="center">
   * {@code "/<1st-root>/momelog.log"}
   * </p>
   * </td>
   * </tr>
   * <tr>
   * <td>
   * <p align="left">
   * <strong>&quot;append&quot;</strong>
   * </p>
   * </td>
   * <td>
   * <p align="left">
   * If {@code false}, destination file is rewritten on open, if it already
   * exists. If {@code true} and destination file exists, no
   * {@code header} is written and logging lines are appended to the end of the
   * destination file. The default value is {@code false}.
   * </p>
   * <p>
   * <strong>Note:</strong> Spaces around value of this property are ignored.
   * </p>
   * <p>
   * <em>Since version 1.0</em>
   * </p>
   * </td>
   * <td>
   * <p align="center">
   * {@code false}
   * </p>
   * </td>
   * </tr>
   * <tr>
   * <td>
   * <p align="left">
   * <strong>&quot;encoding&quot;</strong>
   * </p>
   * </td>
   * <td>
   * <p align="left">
   * Specifies character encoding to be used for writing the destination file.
   * The default value is {@code UTF-8}.
   * </p>
   * <p>
   * <strong>Note:</strong> Spaces around value of this property are ignored.
   * </p>
   * <p>
   * <em>Since version 1.0</em>
   * </p>
   * </td>
   * <td>
   * <p align="center">
   * {@code UTF-8}
   * </p>
   * </td>
   * </tr>
   * <tr>
   * <td>
   * <p align="left">
   * <strong>&quot;footer&quot;</strong>
   * </p>
   * </td>
   * <td>
   * <p align="left">
   * Specifies line to be written at the end of the destination file. The
   * default value is {@code null} (i.e. no line is written).
   * </p>
   * <p>
   * <strong>Note:</strong> {@code footer} line is only written, if method
   * {@link #close()} is called at the end of the application's run (e.g. from
   * {@code MIDlet.destroyApp(boolean unconditional)} method).
   * </p>
   * <p>
   * <strong>Note:</strong> Spaces around value of this property are
   * <strong>significant</strong>.
   * </p>
   * <p>
   * <em>Since version 1.0</em>
   * </p>
   * </td>
   * <td>
   * <p align="center">
   * {@code null} (no line is written).
   * </p>
   * </td>
   * </tr>
   * <tr>
   * <td>
   * <p align="left">
   * <strong>&quot;header&quot;</strong>
   * </p>
   * </td>
   * <td>
   * <p align="left">
   * Specifies line to be written at the start of the destination file. The
   * default value is {@code null} (i.e. no line is written).
   * </p>
   * <p>
   * <strong>Note:</strong> {@code header} line is only written, if 
   * {@link LogFile} creates or rewrites the destination file.
   * </p>
   * <p>
   * <strong>Note:</strong> Spaces around value of this property are
   * <strong>significant</strong>.
   * </p>
   * <p>
   * <em>Since version 1.0</em>
   * </p>
   * </td>
   * <td>
   * <p align="center">
   * {@code null} (no line is written).
   * </p>
   * </td>
   * </tr>
   * <tr>
   * <td>
   * <p align="left">
   * <strong>&quot;prefix&quot;</strong>
   * </p>
   * </td>
   * <td>
   * <p align="left">
   * Specifies string to be written at the start of each logging line. The
   * default value is {@code null} (i.e. no string is written).
   * </p>
   * <p>
   * <strong>Note:</strong> Spaces around value of this property are
   * <strong>significant</strong>.
   * </p>
   * <p>
   * <em>Since version 1.0</em>
   * </p>
   * </td>
   * <td>
   * <p align="center">
   * {@code null} (no string is written).
   * </p>
   * </td>
   * </tr>
   * <tr>
   * <td>
   * <p align="left">
   * <strong>&quot;suffix&quot;</strong>
   * </p>
   * </td>
   * <td>
   * <p align="left">
   * Specifies string to be written at the end of each logging line. The default
   * value is {@code null} (i.e. no string is written).
   * </p>
   * <p>
   * <strong>Note:</strong> Spaces around value of this property are
   * <strong>significant</strong>.
   * </p>
   * <p>
   * <em>Since version 1.0</em>
   * </p>
   * </td>
   * <td>
   * <p align="center">
   * {@code null} (no string is written).
   * </p>
   * </td>
   * </tr>
   * </table>
   * 
   * <p>
   * For example: following configuration file snippet configures
   * {@link LogFile} to append all logging to the existent file
   * {@code "/root2/logs/my-app.log} using {@code UTF-16} encoding, sets
   * {@code header} and {@code footer} to
   * {@code '   ***  Logging from MyApp   ***   '}, prefix to {@code '['} and
   * suffix to {@code ']'}.
   * </p>
   * 
   * <pre>
   *    
   *  #setting LogListener
   *  listener = momelog.listener.LogFile
   *    
   *  #setting log file.
   *  listener.outfile = /root2/logs/my-app.log
   *    
   *  #don't rewrite
   *  listener.append = true
   *    
   *  #encoding setting.
   *  listener.encoding = UTF-16
   *    
   *  #header setting. spaces are significant.
   *  listener.header =   ***  Logging from MyApp   ***
   *  #footer setting. spaces are significant.
   *  listener.footer =   ***  Logging from MyApp   ***
   *  #prefix setting. spaces are significant.
   *  listener.prefix =[
   *  #suffix setting. spaces are significant.
   *  listener.suffix =]
   * </pre>
   * 
   * @see momelog.Configurable#configure(char[], int, int)
   */
  public void configure(char[] lines, int offset, int length)
  {
    if (length < 0)
      throw new IllegalArgumentException("length: " + length + " < 0");
    if (offset < 0 || offset > lines.length)
      throw new ArrayIndexOutOfBoundsException("offset: "
          + Integer.toString(offset));
    if ((length += offset) > lines.length)
      length = lines.length;

    if (length > offset)
    {
      for (int lineEnd = offset; lineEnd < length; offset = ++lineEnd)
      {
        for (; offset < length
            && (lines[offset] == ' ' || lines[offset] == '\t'); offset++);
        for (lineEnd = offset; lineEnd < length && lines[lineEnd] != '\n'; lineEnd++);
        int nameEnd = offset;
        boolean notValid = true;
        for (; nameEnd < lineEnd && (notValid = (lines[nameEnd] != '=')); nameEnd++);
        if (!notValid)
        {
          int vStart = (nameEnd--) + 1;
          int vEnd = lineEnd;

          for (; nameEnd >= offset
              && (lines[nameEnd] == ' ' || lines[nameEnd] == '\t'); nameEnd--);
          String name = String.valueOf(lines, offset, ++nameEnd - offset);
          nameEnd = vStart;
          for (; vStart < length
              && (lines[vStart] == ' ' || lines[vStart] == '\t'); vStart++);
          for (int pos = vEnd - 1; vStart <= pos
              && (lines[pos] == ' ' || lines[pos] == '\t'); vEnd = pos--);
          try
          {
            if (name.equals("outfile"))
              setOutfile(String.valueOf(lines, vStart, vEnd - vStart));
            else if (name.equals("encoding"))
              setEncoding(String.valueOf(lines, vStart, vEnd - vStart));
            else if (name.equals("header"))
              setHeader(String.valueOf(lines, nameEnd, lineEnd - nameEnd));
            else if (name.equals("fotter"))
              setFooter(String.valueOf(lines, nameEnd, lineEnd - nameEnd));
            else if (name.equals("prefix"))
              setPrefix(String.valueOf(lines, nameEnd, lineEnd - nameEnd));
            else if (name.equals("suffix"))
              setSuffix(String.valueOf(lines, nameEnd, lineEnd - nameEnd));
            else if (name.equals("append"))
            {
              String value = String.valueOf(lines, vStart, vEnd - vStart);
              setAppend(value.equalsIgnoreCase("true")
                  || value.equalsIgnoreCase("yes")
                  || value.equalsIgnoreCase("on"));
            } else System.err.println("ERROR: Unknown property " + name
                + " of " + LogFile.class.getName() + ". Ignored.");
          } catch (Throwable e)
          {
            String message = e.getMessage();
            if (message != null && message.length() > 0)
              message = ": " + message;
            System.err.println("ERROR: Invalid value \""
                + String.valueOf(lines, vStart, vEnd - vStart)
                + "\" of property " + name + " of " + LogFile.class.getName()
                + message + ". Ignored.");
          }
        } else System.err.println("ERROR: Invalid properties line "
            + "\"listener." + String.valueOf(lines, offset, lineEnd - offset)
            + "\" of " + LogFile.class.getName() + ". Ignored.");
      }
    }
  }
}