constructor.java

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  /**
   * Get a String representation of the Constructor. A Constructor's String
   * representation is "<modifier> <classname>(<paramtypes>)
   * throws <exceptions>", where everything after ')' is omitted if
   * there are no exceptions.<br> Example:
   * <code>public java.io.FileInputStream(java.lang.Runnable)
   * throws java.io.FileNotFoundException</code>
   *
   * @return the String representation of the Constructor
   */
  public String toString()
  {
    // 128 is a reasonable buffer initial size for constructor
    StringBuilder sb = new StringBuilder(128);
    Modifier.toString(getModifiers(), sb).append(' ');
    sb.append(getDeclaringClass().getName()).append('(');
    Class[] c = getParameterTypes();
    if (c.length > 0)
      {
        sb.append(ClassHelper.getUserName(c[0]));
        for (int i = 1; i < c.length; i++)
          sb.append(',').append(ClassHelper.getUserName(c[i]));
      }
    sb.append(')');
    c = getExceptionTypes();
    if (c.length > 0)
      {
        sb.append(" throws ").append(c[0].getName());
        for (int i = 1; i < c.length; i++)
          sb.append(',').append(c[i].getName());
      }
    return sb.toString();
  }

  /* FIXME[GENERICS]: Add X extends GenericDeclaration and TypeVariable<X> */
  static void addTypeParameters(StringBuilder sb, TypeVariable[] typeArgs)
  {
    if (typeArgs.length == 0)
      return;
    sb.append('<');
    for (int i = 0; i < typeArgs.length; ++i)
      {
        if (i > 0)
          sb.append(',');
        sb.append(typeArgs[i]);
      }
    sb.append("> ");
  }

  public String toGenericString()
  {
    StringBuilder sb = new StringBuilder(128);
    Modifier.toString(getModifiers(), sb).append(' ');
    addTypeParameters(sb, getTypeParameters());
    sb.append(getDeclaringClass().getName()).append('(');
    Type[] types = getGenericParameterTypes();
    if (types.length > 0)
      {
        sb.append(types[0]);
        for (int i = 1; i < types.length; ++i)
          sb.append(',').append(types[i]);
      }
    sb.append(')');
    types = getGenericExceptionTypes();
    if (types.length > 0)
      {
        sb.append(" throws ").append(types[0]);
        for (int i = 1; i < types.length; i++)
          sb.append(',').append(types[i]);
      }
    return sb.toString();
  }

  /**
   * Create a new instance by invoking the constructor. Arguments are
   * automatically unwrapped and widened, if needed.<p>
   *
   * If this class is abstract, you will get an
   * <code>InstantiationException</code>. If the constructor takes 0
   * arguments, you may use null or a 0-length array for <code>args</code>.<p>
   *
   * If this Constructor enforces access control, your runtime context is
   * evaluated, and you may have an <code>IllegalAccessException</code> if
   * you could not create this object in similar compiled code. If the class
   * is uninitialized, you trigger class initialization, which may end in a
   * <code>ExceptionInInitializerError</code>.<p>
   *
   * Then, the constructor is invoked. If it completes normally, the return
   * value will be the new object. If it completes abruptly, the exception is
   * wrapped in an <code>InvocationTargetException</code>.
   *
   * @param args the arguments to the constructor
   * @return the newly created object
   * @throws IllegalAccessException if the constructor could not normally be
   *         called by the Java code (i.e. it is not public)
   * @throws IllegalArgumentException if the number of arguments is incorrect;
   *         or if the arguments types are wrong even with a widening
   *         conversion
   * @throws InstantiationException if the class is abstract
   * @throws InvocationTargetException if the constructor throws an exception
   * @throws ExceptionInInitializerError if construction triggered class
   *         initialization, which then failed
   */
  public Object newInstance(Object args[])
    throws InstantiationException, IllegalAccessException,
           InvocationTargetException
  {
    return constructNative(args, declaringClass, parameterTypes, slot, flag);
  }

  /**
   * Returns an array of <code>TypeVariable</code> objects that represents
   * the type variables declared by this constructor, in declaration order.
   * An array of size zero is returned if this constructor has no type
   * variables.
   *
   * @return the type variables associated with this constructor.
   * @throws GenericSignatureFormatError if the generic signature does
   *         not conform to the format specified in the Virtual Machine
   *         specification, version 3.
   * @since 1.5
   */
  /* FIXME[GENERICS]: Add <Constructor<T>> */
  public TypeVariable[] getTypeParameters()
  {
    String sig = getSignature(declaringClass, slot);
    if (sig == null)
      return new TypeVariable[0];
    MethodSignatureParser p = new MethodSignatureParser(this, sig);
    return p.getTypeParameters();
  }

  /**
   * Returns an array of <code>Type</code> objects that represents
   * the exception types declared by this constructor, in declaration order.
   * An array of size zero is returned if this constructor declares no
   * exceptions.
   *
   * @return the exception types declared by this constructor. 
   * @throws GenericSignatureFormatError if the generic signature does
   *         not conform to the format specified in the Virtual Machine
   *         specification, version 3.
   * @since 1.5
   */
  public Type[] getGenericExceptionTypes()
  {
    String sig = getSignature(declaringClass, slot);
    if (sig == null)
      return getExceptionTypes();
    MethodSignatureParser p = new MethodSignatureParser(this, sig);
    return p.getGenericExceptionTypes();
  }

  /**
   * Returns an array of <code>Type</code> objects that represents
   * the parameter list for this constructor, in declaration order.
   * An array of size zero is returned if this constructor takes no
   * parameters.
   *
   * @return a list of the types of the constructor's parameters
   * @throws GenericSignatureFormatError if the generic signature does
   *         not conform to the format specified in the Virtual Machine
   *         specification, version 3.
   * @since 1.5
   */
  public Type[] getGenericParameterTypes()
  {
    String sig = getSignature(declaringClass, slot);
    if (sig == null)
      return getParameterTypes();
    MethodSignatureParser p = new MethodSignatureParser(this, sig);
    return p.getGenericParameterTypes();
  }

  public Annotation getAnnotation(Class annoClass)
  {
    Annotation[] annos = getDeclaredAnnotations();
    for (int i = 0; i < annos.length; i++)
      if (annos[i].annotationType() == annoClass)
	return annos[i];
    return null;
  }

  public Annotation[] getDeclaredAnnotations()
  {
    return getDeclaredAnnotationsNative(declaringClass, slot);
  }

  public Annotation[][] getParameterAnnotations()
  {
    return getParameterAnnotationsNative(declaringClass, slot);
  }

  /*
   * NATIVE HELPERS
   */

  /**
   * Return the String in the Signature attribute for this constructor. If there
   * is no Signature attribute, return null.
   */
  private native String getSignature(Class declaringClass, int slot);

  /**
   * Return the raw modifiers for this constructor.  In particular
   * this will include the synthetic and varargs bits.
   * @return the constructor's modifiers
   */
  private native int getConstructorModifiers(Class declaringClass, int slot);

  private native Object constructNative(Object[] args, Class declaringClass,
					Class[] parameterTypes, int slot,
					boolean noAccessCheck)
    throws InstantiationException, IllegalAccessException,
           InvocationTargetException;

  private native Annotation[] getDeclaredAnnotationsNative(Class declaringClass, int slot);
  private native Annotation[][] getParameterAnnotationsNative(Class declaringClass, int slot);
}