class.java

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   * <code>checkPackageAccess</code> both having to succeed.
   *
   * @return all declared fields in this class
   * @throws SecurityException if the security check fails
   * @since 1.1
   */
  public Field[] getDeclaredFields()
  {
    memberAccessCheck(Member.DECLARED);
    return getDeclaredFields(false);
  }

  Field[] getDeclaredFields (boolean publicOnly)
  {
    return VMClass.getDeclaredFields (this, publicOnly);
  }

  /**
   * Get a method declared in this class, where name is its simple name. The
   * implicit methods of Object are not available from arrays or interfaces.
   * Constructors (named "&lt;init&gt;" in the class file) and class initializers
   * (name "&lt;clinit&gt;") are not available.  The Virtual Machine allows
   * multiple methods with the same signature but differing return types; in
   * such a case the most specific return types are favored, then the final
   * choice is arbitrary. If the method takes no argument, an array of zero
   * elements and null are equivalent for the types argument. A security
   * check may be performed, with
   * <code>checkMemberAccess(this, Member.DECLARED)</code> as well as
   * <code>checkPackageAccess</code> both having to succeed.
   *
   * @param methodName the name of the method
   * @param types the type of each parameter
   * @return the method
   * @throws NoSuchMethodException if the method does not exist
   * @throws SecurityException if the security check fails
   * @see #getDeclaredMethods()
   * @since 1.1
   */
  public Method getDeclaredMethod(String methodName, Class[] types)
    throws NoSuchMethodException
  {
    memberAccessCheck(Member.DECLARED);
    Method match = matchMethod(getDeclaredMethods(false), methodName, types);
    if (match == null)
      throw new NoSuchMethodException(methodName);
    return match;
  }

  /**
   * Get all the declared methods in this class, but not those inherited from
   * superclasses. This returns an array of length 0 if there are no methods,
   * including for primitive types. This does include the implicit methods of
   * arrays and interfaces which mirror methods of Object, nor does it
   * include constructors or the class initialization methods. The Virtual
   * Machine allows multiple methods with the same signature but differing
   * return types; all such methods are in the returned array. A security
   * check may be performed, with
   * <code>checkMemberAccess(this, Member.DECLARED)</code> as well as
   * <code>checkPackageAccess</code> both having to succeed.
   *
   * @return all declared methods in this class
   * @throws SecurityException if the security check fails
   * @since 1.1
   */
  public Method[] getDeclaredMethods()
  {
    memberAccessCheck(Member.DECLARED);
    return getDeclaredMethods(false);
  }

  Method[] getDeclaredMethods (boolean publicOnly)
  {
    return VMClass.getDeclaredMethods (this, publicOnly);
  }
 
  /**
   * If this is a nested or inner class, return the class that declared it.
   * If not, return null.
   *
   * @return the declaring class of this class
   * @since 1.1
   */
  public Class getDeclaringClass()
  {
    return VMClass.getDeclaringClass (this);
  }

  /**
   * Get a public field declared or inherited in this class, where name is
   * its simple name. If the class contains multiple accessible fields by
   * that name, an arbitrary one is returned. The implicit length field of
   * arrays is not available. A security check may be performed, with
   * <code>checkMemberAccess(this, Member.PUBLIC)</code> as well as
   * <code>checkPackageAccess</code> both having to succeed.
   *
   * @param fieldName the name of the field
   * @return the field
   * @throws NoSuchFieldException if the field does not exist
   * @throws SecurityException if the security check fails
   * @see #getFields()
   * @since 1.1
   */
  public Field getField(String fieldName)
    throws NoSuchFieldException
  {
    memberAccessCheck(Member.PUBLIC);
    Field field = internalGetField(fieldName);
    if (field == null)
      throw new NoSuchFieldException(fieldName);
    return field;
  }

  /**
   * Get all the public fields declared in this class or inherited from
   * superclasses. This returns an array of length 0 if there are no fields,
   * including for primitive types. This does not return the implicit length
   * field of arrays. A security check may be performed, with
   * <code>checkMemberAccess(this, Member.PUBLIC)</code> as well as
   * <code>checkPackageAccess</code> both having to succeed.
   *
   * @return all public fields in this class
   * @throws SecurityException if the security check fails
   * @since 1.1
   */
  public Field[] getFields()
  {
    memberAccessCheck(Member.PUBLIC);
    return internalGetFields();
  }

  /**
   * Like <code>getFields()</code> but without the security checks.
   */
  private Field[] internalGetFields()
  {
    HashSet set = new HashSet();
    set.addAll(Arrays.asList(getDeclaredFields(true)));
    Class[] interfaces = getInterfaces();
    for (int i = 0; i < interfaces.length; i++)
      set.addAll(Arrays.asList(interfaces[i].internalGetFields()));
    Class superClass = getSuperclass();
    if (superClass != null)
      set.addAll(Arrays.asList(superClass.internalGetFields()));
    return (Field[])set.toArray(new Field[set.size()]);
  }

  /**
   * Returns the <code>Package</code> in which this class is defined
   * Returns null when this information is not available from the
   * classloader of this class or when the classloader of this class
   * is null.
   *
   * @return the package for this class, if it is available
   * @since 1.2
   */
  public Package getPackage()
  {
    ClassLoader cl = getClassLoader();
    if (cl != null)
      return cl.getPackage(getPackagePortion(getName()));
    else
      return VMClassLoader.getPackage(getPackagePortion(getName()));
  }

  /**
   * Get the interfaces this class <em>directly</em> implements, in the
   * order that they were declared. This returns an empty array, not null,
   * for Object, primitives, void, and classes or interfaces with no direct
   * superinterface. Array types return Cloneable and Serializable.
   *
   * @return the interfaces this class directly implements
   */
  public Class[] getInterfaces()
  {
    return VMClass.getInterfaces (this);
  }

  private static final class MethodKey
  {
    private String name;
    private Class[] params;
    private Class returnType;
    private int hash;
    
    MethodKey(Method m)
    {
      name = m.getName();
      params = m.getParameterTypes();
      returnType = m.getReturnType();
      hash = name.hashCode() ^ returnType.hashCode();
      for(int i = 0; i < params.length; i++)
	{
	  hash ^= params[i].hashCode();
	}
    }
    
    public boolean equals(Object o)
    {
      if(o instanceof MethodKey)
	{
	  MethodKey m = (MethodKey)o;
	  if(m.name.equals(name) && m.params.length == params.length && m.returnType == returnType)
	    {
	      for(int i = 0; i < params.length; i++)
		{
		  if(m.params[i] != params[i])
		    {
		      return false;
		    }
		}
	      return true;
	    }
	}
      return false;
    }
    
    public int hashCode()
    {
      return hash;
    }
  }
  
  /**
   * Get a public method declared or inherited in this class, where name is
   * its simple name. The implicit methods of Object are not available from
   * interfaces.  Constructors (named "&lt;init&gt;" in the class file) and class
   * initializers (name "&lt;clinit&gt;") are not available.  The Virtual
   * Machine allows multiple methods with the same signature but differing
   * return types, and the class can inherit multiple methods of the same
   * return type; in such a case the most specific return types are favored,
   * then the final choice is arbitrary. If the method takes no argument, an
   * array of zero elements and null are equivalent for the types argument.
   * A security check may be performed, with
   * <code>checkMemberAccess(this, Member.PUBLIC)</code> as well as
   * <code>checkPackageAccess</code> both having to succeed.
   *
   * @param methodName the name of the method
   * @param types the type of each parameter
   * @return the method
   * @throws NoSuchMethodException if the method does not exist
   * @throws SecurityException if the security check fails
   * @see #getMethods()
   * @since 1.1
   */
  public Method getMethod(String methodName, Class[] types)
    throws NoSuchMethodException
  {
    memberAccessCheck(Member.PUBLIC);
    Method method = internalGetMethod(methodName, types);
    if (method == null)
      throw new NoSuchMethodException(methodName);
    return method;
  }

  /**
   * Like <code>getMethod(String,Class[])</code> but without the security
   * checks and returns null instead of throwing NoSuchMethodException.
   */
  private Method internalGetMethod(String methodName, Class[] args)
  {
    Method match = matchMethod(getDeclaredMethods(true), methodName, args);
    if (match != null)
      return match;
    Class superClass = getSuperclass();
    if (superClass != null)
      {
	match = superClass.internalGetMethod(methodName, args);
	if(match != null)
	  return match;
      }
    Class[] interfaces = getInterfaces();
    for (int i = 0; i < interfaces.length; i++)
      {
	match = interfaces[i].internalGetMethod(methodName, args);
	if (match != null)
	  return match;
      }
    return null;
  }

  /** 
   * Find the best matching method in <code>list</code> according to
   * the definition of ``best matching'' used by <code>getMethod()</code>
   *
   * <p>
   * Returns the method if any, otherwise <code>null</code>.
   *
   * @param list List of methods to search
   * @param name Name of method
   * @param args Method parameter types
   * @see #getMethod(String, Class[])
   */
  private static Method matchMethod(Method[] list, String name, Class[] args)
  {
    Method match = null;
    for (int i = 0; i < list.length; i++)
      {
	Method method = list[i];
	if (!method.getName().equals(name))
	  continue;
	if (!matchParameters(args, method.getParameterTypes()))
	  continue;
	if (match == null
	    || match.getReturnType().isAssignableFrom(method.getReturnType()))
	  match = method;
      }
    return match;
  }

  /**
   * Check for an exact match between parameter type lists.
   * Either list may be <code>null</code> to mean a list of
   * length zero.
   */
  private static boolean matchParameters(Class[] types1, Class[] types2)
  {
    if (types1 == null)
      return types2 == null || types2.length == 0;
    if (types2 == null)
      return types1 == null || types1.length == 0;
    if (types1.length != types2.length)
      return false;
    for (int i = 0; i < types1.length; i++)
      {
	if (types1[i] != types2[i])
	  return false;
      }
    return true;
  }
  
  /**
   * Get all the public methods declared in this class or inherited from
   * superclasses. This returns an array of length 0 if there are no methods,
   * including for primitive types. This does not include the implicit
   * methods of interfaces which mirror methods of Object, nor does it
   * include constructors or the class initialization methods. The Virtual
   * Machine allows multiple methods with the same signature but differing
   * return types; all such methods are in the returned array. A security
   * check may be performed, with
   * <code>checkMemberAccess(this, Member.PUBLIC)</code> as well as
   * <code>checkPackageAccess</code> both having to succeed.
   *
   * @return all public methods in this class
   * @throws SecurityException if the security check fails
   * @since 1.1
   */
  public Method[] getMethods()
  {
    memberAccessCheck(Member.PUBLIC);
    // NOTE the API docs claim that no methods are returned for arrays,
    // but Sun's implementation *does* return the public methods of Object
    // (as would be expected), so we follow their implementation instead
    // of their documentation.
    return internalGetMethods();
  }

  /**
   * Like <code>getMethods()</code> but without the security checks.
   */
  private Method[] internalGetMethods()
  {
    HashMap map = new HashMap();
    Method[] methods;
    Class[] interfaces = getInterfaces();
    for(int i = 0; i < interfaces.length; i++)
      {
	methods = interfaces[i].internalGetMethods();
	for(int j = 0; j < methods.length; j++)
	  {
	    map.put(new MethodKey(methods[j]), methods[j]);
	  }
      }
    Class superClass = getSuperclass();
    if(superClass != null)
      {
	methods = superClass.internalGetMethods();
	for(int i = 0; i < methods.length; i++)
	  {
	    map.put(new MethodKey(methods[i]), methods[i]);
	  }
      }
    methods = getDeclaredMethods(true);
    for(int i = 0; i < methods.length; i++)
      {
	map.put(new MethodKey(methods[i]), methods[i]);
      }
    return (Method[])map.values().toArray(new Method[map.size()]);
  }

  /**
   * Get the modifiers of this class.  These can be decoded using Modifier,
   * and is limited to one of public, protected, or private, and any of
   * final, static, abstract, or interface. An array class has the same
   * public, protected, or private modifier as its component type, and is
   * marked final but not an interface. Primitive types and void are marked
   * public and final, but not an interface.
   *
   * @return the modifiers of this class
   * @see Modifier
   * @since 1.1
   */
  public int getModifiers()
  {
    return VMClass.getModifiers (this, false);
  }
  
  /**
   * Get the name of this class, separated by dots for package separators.
   * If the class represents a primitive type, or void, then the
   * name of the type as it appears in the Java programming language
   * is returned.  For instance, <code>Byte.TYPE.getName()</code>
   * returns "byte".
   *
   * Arrays are specially encoded as shown on this table.
   * <pre>
   * array type          [<em>element type</em>
   *                     (note that the element type is encoded per
   *                      this table)
   * boolean             Z
   * byte                B
   * char                C
   * short               S
   * int                 I
   * long                J
   * float               F
   * double              D
   * void                V
   * class or interface, alone: &lt;dotted name&gt;
   * class or interface, as element type: L&lt;dotted name&gt;;
   * </pre>
   *
   * @return the name of this class
   */
  public String getName()
  { 
    return VMClass.getName (this);