field.java

来自「java jdk 1.4的源码」· Java 代码 · 共 835 行 · 第 1/2 页

/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written 
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, Lotus
 * Development Corporation., http://www.lotus.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xml.utils.synthetic.reflection;

import org.apache.xml.utils.synthetic.Class;
import org.apache.xml.utils.synthetic.SynthesisException;

/**
 * <meta name="usage" content="internal"/>
 * A Field provides information about, and dynamic access
 * to, a single field of a class or an interface. The reflected
 * field may be a class (static) field or an instance field.
 * <p>
 * A Field permits widening conversions to occur during a
 * get or set access operation, but throws an
 * IllegalArgumentException if a narrowing conversion
 * would occur.
 *
 */
public class Field extends Object implements Member
{

  /** Field name, initializer          */
  public String name, initializer = null;

  /** Field modifiers          */
  int modifiers;

  /** Field realfield          */
  java.lang.reflect.Field realfield = null;

  /** Field declaringClass, type          */
  Class declaringClass, type;

  /**
   * Proxy constructor 
   *
   * @param realfield
   * @param declaringClass
   */
  public Field(java.lang.reflect.Field realfield,
               org.apache.xml.utils.synthetic.Class declaringClass)
  {

    this(realfield.getName(), declaringClass);

    this.realfield = realfield;
    this.type =
      org.apache.xml.utils.synthetic.Class.forClass(realfield.getType());
  }

  /**
   * Synthesis constructor 
   *
   * @param name
   * @param declaringClass
   */
  public Field(String name,
               org.apache.xml.utils.synthetic.Class declaringClass)
  {
    this.name = name;
    this.declaringClass = declaringClass;
  }

  /**
   * Compares this Field against the specified object.
   * Returns true if the objects are the same. Two
   * Fields are the same if they were declared by the
   * same class and have the same name and type.
   *
   * @param obj
   *
   */
  public boolean equals(Object obj)
  {

    if (realfield != null)
      return realfield.equals(obj);
    else if (obj instanceof Field)
    {
      Field objf = (Field) obj;

      return (declaringClass.equals(objf.declaringClass)
              && name.equals(objf.name) && type.equals(objf.type));
    }
    else
      return false;
  }

  /**
   * Returns the value of the field represented by this
   * Field, on the specified object. The value is
   * automatically wrapped in an object if it has a
   * primitive type.
   * <p>
   * The underlying field's value is obtained as follows:
   * <p>
   * If the underlying field is a static field, the object
   * argument is ignored; it may be null.
   * <p>
   * Otherwise, the underlying field is an instance
   * field. If the specified object argument is null, the
   * method throws a NullPointerException. If the
   * specified object is not an instance of the class or
   * interface declaring the underlying field, the
   * method throws an IllegalArgumentException.
   * <p>
   * If this Field object enforces Java language access
   * control, and the underlying field is inaccessible,
   * the method throws an IllegalAccessException.
   * <p>
   * Otherwise, the value is retrieved from the
   * underlying instance or static field. If the field has a
   * primitive type, the value is wrapped in an object
   * before being returned, otherwise it is returned as
   * is.
   *
   *
   * @param obj
   *
   * @throws IllegalAccessException
   * if the underlying constructor is inaccessible.
   * @throws IllegalArgumentException
   * if the specified object is not an instance of
   * the class or interface declaring the
   * underlying field.
   * @throws NullPointerException
   * if the specified object is null.
   */
  public Object get(Object obj)
          throws IllegalArgumentException, IllegalAccessException
  {

    if (realfield != null)
      return realfield.get(obj);

    throw new java.lang.IllegalStateException();
  }

  /**
   * Get the value of a field as a boolean on specified
   * object.
   *
   *
   * @param obj
   *
   * @throws IllegalAccessException
   * if the underlying constructor is inaccessible.
   * @throws IllegalArgumentException
   * if the field value cannot be converted to the
   * return type by a widening conversion.
   */
  public boolean getBoolean(Object obj)
          throws IllegalArgumentException, IllegalAccessException
  {

    if (realfield != null)
      return realfield.getBoolean(obj);

    throw new java.lang.IllegalStateException();
  }

  /**
   * Get the value of a field as a byte on specified
   * object.
   *
   *
   * @param obj
   *
   * @throws IllegalAccessException
   * if the underlying constructor is inaccessible.
   * @throws IllegalArgumentException
   * if the field value cannot be converted to the
   * return type by a widening conversion.
   */
  public byte getByte(Object obj)
          throws IllegalArgumentException, IllegalAccessException
  {

    if (realfield != null)
      return realfield.getByte(obj);

    throw new java.lang.IllegalStateException();
  }

  /**
   * Get the value of a field as a char on specified
   * object.
   *
   *
   * @param obj
   *
   * @throws IllegalAccessException
   * if the underlying constructor is inaccessible.
   * @throws IllegalArgumentException
   * if the field value cannot be converted to the
   * return type by a widening conversion.
   */
  public char getChar(Object obj)
          throws IllegalArgumentException, IllegalAccessException
  {

    if (realfield != null)
      return realfield.getChar(obj);

    throw new java.lang.IllegalStateException();
  }

  /**
   * Returns the Class object representing the class or
   * interface that declares the field represented by this
   * Field object.
   *
   */
  public org.apache.xml.utils.synthetic.Class getDeclaringClass()
  {

    if (realfield != null)
      return org.apache.xml.utils.synthetic.Class.forClass(
        realfield.getDeclaringClass());

    throw new java.lang.IllegalStateException();
  }

  /**
   * Get the value of a field as a double on specified
   * object.
   *
   *
   * @param obj
   *
   * @throws IllegalAccessException
   * if the underlying constructor is inaccessible.
   * @throws IllegalArgumentException
   * if the field value cannot be converted to the
   * return type by a widening conversion.
   */
  public double getDouble(Object obj)
          throws IllegalArgumentException, IllegalAccessException
  {

    if (realfield != null)
      return realfield.getDouble(obj);

    throw new java.lang.IllegalStateException();
  }

  /**
   * Get the value of a field as a float on specified
   * object.
   *
   *
   * @param obj
   *
   * @throws IllegalAccessException
   * if the underlying constructor is inaccessible.
   * @throws IllegalArgumentException
   * if the field value cannot be converted to the
   * return type by a widening conversion.
   */
  public float getFloat(Object obj)
          throws IllegalArgumentException, IllegalAccessException
  {

    if (realfield != null)
      return realfield.getFloat(obj);

    throw new java.lang.IllegalStateException();
  }

  /**
   * Get the value of a field as a int on specified object.
   *
   *
   * @param obj
   *
   * @throws IllegalAccessException
   * if the underlying constructor is inaccessible.
   * @throws IllegalArgumentException
   * if the field value cannot be converted to the
   * return type by a widening conversion.
   */
  public int getInt(Object obj)
          throws IllegalArgumentException, IllegalAccessException
  {

    if (realfield != null)
      return realfield.getInt(obj);

    throw new java.lang.IllegalStateException();
  }

  /**
   * Get the value of a field as a long on specified
   * object.
   *
   *
   * @param obj
   *
   * @throws IllegalAccessException
   * if the underlying constructor is inaccessible.
   * @throws IllegalArgumentException
   * if the field value cannot be converted to the
   * return type by a widening conversion.
   */
  public long getLong(Object obj)
          throws IllegalArgumentException, IllegalAccessException
  {

    if (realfield != null)
      return realfield.getLong(obj);

    throw new java.lang.IllegalStateException();
  }

  /**
   * Returns the Java language modifiers for the field
   * represented by this Field object, as an integer. The
   * Modifier class should be used to decode the
   * modifiers.
   *
   */
  public int getModifiers()
  {

    if (realfield != null)
      modifiers = realfield.getModifiers();

    return modifiers;
  }

  /**
   * Method getInitializer 
   *
   *
   * (getInitializer) @return
   */
  public String getInitializer()
  {
    return initializer;
  }

  /**
   * Method setInitializer 
   *
   *
   * @param i
   *
   * @throws SynthesisException
   */
  public void setInitializer(String i) throws SynthesisException
  {

    if (realfield != null)
      throw new SynthesisException(SynthesisException.REIFIED);

    initializer = i;
  }

  /**
   * Insert the method's description here.
   * Creation date: (12-25-99 2:02:26 PM)
   * @return java.lang.String
   */