expr.java

来自「RESIN 3.2 最新源码」· Java 代码 · 共 1,371 行 · 第 1/3 页

  }

  @Override
  public Class<?> getExpectedType()
  {
    return Object.class;
  }

  @Override
  public Class<?> getType(ELContext context)
    throws PropertyNotFoundException,
	   ELException
  {
    Object value = getValue(context);

    if (value == null)
      return null;
    else
      return value.getClass();
  }

  //
  // Static convenience methods
  //

  /**
   * Returns true for a double or double-equivalent.
   */
  public static boolean isDouble(Object o)
  {
    if (o instanceof Double)
      return true;
    else if (o instanceof Float)
      return true;
    else if (! (o instanceof String))
      return false;
    else {
      String s = (String) o;
      int len = s.length();

      for (int i = 0; i < len; i++) {
	char ch = s.charAt(i);

	if (ch == '.' || ch == 'e' || ch == 'E')
	  return true;
      }

      return false;
    }
  }

  /**
   * Converts some unknown value to a string.
   *
   * @param value the value to be converted.
   *
   * @return the string-converted value.
   */
  public static String toStringWithNull(Object value, ELContext env)
  {
    if (value == null || value instanceof String)
      return (String) value;
    else
      return value.toString();
  }

  /**
   * Converts some unknown value to a string.
   *
   * @param value the value to be converted.
   *
   * @return the string-converted value.
   */
  public static String toString(Object value, ELContext env)
  {
    if (value == null)
      return "";
    else if (value instanceof String)
      return (String) value;
    else
      return value.toString();
  }

  /**
   * Converts some unknown value to a string.
   *
   * @param value the value to be converted.
   *
   * @return the string-converted value.
   */
  public static String toString(long value, ELContext env)
  {
    return String.valueOf(value);
  }

  /**
   * Converts some unknown value to a string.
   *
   * @param value the value to be converted.
   *
   * @return the string-converted value.
   */
  public static String toString(double value, ELContext env)
  {
    return String.valueOf(value);
  }

  /**
   * Converts some unknown value to a string.
   *
   * @param value the value to be converted.
   *
   * @return the string-converted value.
   */
  public static String toString(boolean value, ELContext env)
  {
    return String.valueOf(value);
  }

  /**
   * Converts some unknown value to a string.
   *
   * @param value the value to be converted.
   *
   * @return the string-converted value.
   */
  public static String toString(char value, ELContext env)
  {
    return String.valueOf(value);
  }

  /**
   * Converts some unknown value to a string.
   *
   * @param value the value to be converted.
   *
   * @return the string-converted value.
   */
  public static char toCharacter(Object value, ELContext env)
    throws ELException
  {
    if (value == null)
      return (char) 0;
    else if (value instanceof Character) {
      return ((Character) value).charValue();
    }
    else if (value instanceof String) {
      String s = (String) value;

      if (s == null || s.length() == 0)
	return (char) 0;
      else
	return s.charAt(0);
    }
    else if (value instanceof Number) {
      Number number = (Number) value;

      return (char) number.intValue();
    }
    else if (value instanceof Boolean) {
      ELException e = new ELException(L.l("can't convert {0} to character.",
                                          value.getClass().getName()));

      throw e;
      /*
      error(e, env);

      return (char) 0;
      */
    }
    else
      return (char) toLong(value, env);
  }

  /**
   * Converts some unknown value to a boolean.
   *
   * @param value the value to be converted.
   *
   * @return the boolean-converted value.
   */
  public static boolean toBoolean(Object value, ELContext env)
    throws ELException
  {
    if (value == null || value.equals(""))
      return false;
    else if (value instanceof Boolean)
      return ((Boolean) value).booleanValue();
    else if (value instanceof String)
      return value.equals("true") || value.equals("yes");
    else {
      ELException e = new ELException(L.l("can't convert {0} to boolean.",
                                          value.getClass().getName()));

      // jsp/18s1
      throw e;
      /*
      error(e, env);

      return false;
      */
    }
  }

  /**
   * Converts some unknown value to a double.
   *
   * @param value the value to be converted.
   *
   * @return the double-converted value.
   */
  public static double toDouble(Object value, ELContext env)
    throws ELException
  {
    if (value == null)
      return 0;
    else if (value instanceof Number) {
      double dValue = ((Number) value).doubleValue();

      if (Double.isNaN(dValue))
        return 0;
      else
        return dValue;
    }
    else if (value.equals(""))
      return 0;
    else if (value instanceof String) {
      double dValue = Double.parseDouble((String) value);

      if (Double.isNaN(dValue))
        return 0;
      else
        return dValue;
    }
    else if (value instanceof Character) {
      // jsp/18s7
      return ((Character) value).charValue();
    }
    else {
      ELException e = new ELException(L.l("can't convert {0} to double.",
                                          value.getClass().getName()));
      
      // error(e, env);

      // return 0;

      throw e;
    }
  }

  /**
   * Converts some unknown value to a big decimal
   *
   * @param value the value to be converted.
   *
   * @return the BigDecimal-converted value.
   */
  public static BigDecimal toBigDecimal(Object value, ELContext env)
    throws ELException
  {
    if (value == null)
      return BIG_DECIMAL_ZERO;
    else if  (value instanceof BigDecimal)
      return (BigDecimal) value;
    else if (value instanceof Number) {
      double dValue = ((Number) value).doubleValue();

      return new BigDecimal(dValue);
    }
    else if (value.equals(""))
      return BIG_DECIMAL_ZERO;
    else if (value instanceof String) {
      return new BigDecimal((String) value);
    }
    else if (value instanceof Character) {
      return new BigDecimal(((Character) value).charValue());
    }
    else {
      ELException e = new ELException(L.l("can't convert {0} to BigDecimal.",
                                          value.getClass().getName()));
      
      error(e, env);

      return BIG_DECIMAL_ZERO;
    }
  }

  /**
   * Converts some unknown value to a big integer
   *
   * @param value the value to be converted.
   *
   * @return the BigInteger-converted value.
   */
  public static BigInteger toBigInteger(Object value, ELContext env)
    throws ELException
  {
    if (value == null)
      return BIG_INTEGER_ZERO;
    else if  (value instanceof BigInteger)
      return (BigInteger) value;
    else if (value instanceof Number) {
      // return new BigInteger(value.toString());
      return new BigDecimal(value.toString()).toBigInteger();
    }
    else if (value.equals(""))
      return BIG_INTEGER_ZERO;
    else if (value instanceof String) {
      return new BigInteger((String) value);
    }
    else if (value instanceof Character) {
      return new BigInteger(String.valueOf((int) ((Character) value).charValue()));
    }
    else {
      ELException e = new ELException(L.l("can't convert {0} to BigInteger.",
                                          value.getClass().getName()));
      
      error(e, env);

      return BIG_INTEGER_ZERO;
    }
  }

  /**
   * Converts some unknown value to a long.
   *
   * @param value the value to be converted.
   *
   * @return the long-converted value.
   */
  public static long toLong(Object value, ELContext env)
    throws ELException
  {
    if (value == null)
      return 0;
    else if (value instanceof Number)
      return ((Number) value).longValue();
    else if (value.equals(""))
      return 0;
    else if (value instanceof String) {
      try {
	return (long) Double.parseDouble((String) value);
      } catch (Exception e) {
	throw new ELException(e);
      }
    }
    else if (value instanceof Character) {
      // jsp/18s6
      return ((Character) value).charValue();
    }
    else {
      ELException e = new ELException(L.l("can't convert {0} to long.",
                                          value.getClass().getName()));
      
      // error(e, env);

      // return 0;

      throw e;
    }
  }

  /**
   * Write to the stream.
   *
   * @param out the output stream
   * @param value the value to be written.
   *
   * @return true for null
   */
  public static boolean toStream(JspWriter out,
				 Object value,
				 boolean isEscaped)
    throws IOException
  {
    if (value == null)
      return true;
    
    if (isEscaped)
      toStreamEscaped(out, value);
    else
      toStream(out, value);

    return false;
  }

  /**
   * Write to the stream.
   *
   * @param out the output stream
   * @param value the value to be written.
   */
  public static void toStream(WriteStream out, Object value)
    throws IOException
  {
    if (value == null)
      return;
    else if (value instanceof String)
      out.print((String) value);
    else if (value instanceof Reader) {
      out.writeStream((Reader) value);
    }
    else
      out.print(value.toString());
  }

  /**
   * Write to the stream.
   *
   * @param out the output stream
   * @param value the value to be written.
   */
  public static void toStream(JspWriter out, Object value)
    throws IOException
  {
    if (value == null)
      return;
    else if (value instanceof String)
      out.print((String) value);
    else if (value instanceof Reader) {
      Reader reader = (Reader) value;
      int ch;

      while ((ch = reader.read()) > 0) {
	out.print((char) ch);
      }
    }
    else
      out.print(value.toString());
  }

  /**
   * Write to the *.java stream escaping Java reserved characters.
   *
   * @param out the output stream to the *.java code.
   *
   * @param value the value to be converted.
   */
  public static void printEscapedString(WriteStream os, String string)
    throws IOException
  {
    int length = string.length();
    for (int i = 0; i < length; i++) {
      char ch = string.charAt(i);

      switch (ch) {
      case '\\':
        os.print("\\\\");
        break;
      case '\n':
        os.print("\\n");
        break;
      case '\r':
        os.print("\\r");
        break;
      case '\"':
        os.print("\\\"");