I’ve always loved Groovy builders concept for handling (mostly creating) hierarchical documents. On the other hand I find StAX, pull-based processing API, to be one of my favorite methods for dealing with simple XML processing. It’s simple and fast, so what more can I ask for? Additionally, thanks to the Jettison project you can also use the StAX API to handle JSON documents. So, basically we can use one simple (standard) API to handle both XML and JSON documents in the same manner. The next logical step is to merge these two great pieces of technology into one.

I want to talk a little about Android. I am very much going to sidestep the holy war about is it or isn’t it Java, except to say, this looks a lot like something that would have been derived from the Danger stack. The commonalities are striking. As a Sidekick owner, I am terribly pleased with “Java-ish” development for that platform, and I think seeing something similar in wide deployment is great. That said…

First, lets talk about the Android UI API. I recall last year at Sun Tech Days,”The Gos” was asked what, in retrospect he would do different with Java. The first thing he came up with was the Swing API. The “747 Cockpit” feel of the API is overwhelming to new users. Frankly, Android takes this to a whole new level. Just look at the JavaDoc for the Checkbox class:

Constants inherited from class android.view.View

FOCUS_BACKWARD, FOCUS_DOWN, FOCUS_FORWARD, FOCUS_LEFT, FOCUS_RIGHT, FOCUS_UP, GONE, INVISIBLE, NORMAL_FOCUS, NO_ID, VIEW_LOG_TAG, VISIBLE, WEAK_FOCUS

			Value
int	FOCUS_BACKWARD	Use with focusSearch(int).	1	0×00000001
int	FOCUS_DOWN	Use with focusSearch(int).	130	0×00000082
int	FOCUS_FORWARD	Use with focusSearch(int).	2	0×00000002
int	FOCUS_LEFT	Use with focusSearch(int).	17	0×00000011
int	FOCUS_RIGHT	Use with focusSearch(int).	66	0×00000042
int	FOCUS_UP	Use with focusSearch(int).	33	0×00000021
int	GONE	This view is invisible, and it doesn’t take any space for layout purposes.	8	0×00000008
int	INVISIBLE	This view is invisible, but it still takes up space for layout purposes.	4	0×00000004
int	NORMAL_FOCUS	This view wants keystrokes.	0	0×00000000
int	NO_ID	Used to mark a View that has no ID.	-1	0xffffffff
String	VIEW_LOG_TAG	The logging tag used by this class with android.util.Log.	“View”
int	VISIBLE	This view is visible.	0	0×00000000
int	WEAK_FOCUS	This view wants keystrokes, but only if none of its children has focus.	2	0×00000002

Fields inherited from class android.view.View

mBottom, mContext, mLayoutParams, mLeft, mOnClickListener, mOnFocusChangeListener, mPaddingBottom, mPaddingLeft, mPaddingRight, mPaddingTop, mParent, mRight, mScrollX, mScrollY, mTag, mTop, mWindowLeft, mWindowTop

protected			int	mBottom	The distance in pixels from the bottom edge of this view’s parent to the bottom edge of this view.
protected			Context	mContext	The application environment this view lives in.
protected			LayoutParams	mLayoutParams	The layout parameters associated with this view and used by the parent ViewGroup to determine how this view should be laid out.
protected			int	mLeft	The distance in pixels from the left edge of this view’s parent to the left edge of this view.
protected			OnClickListener	mOnClickListener	Listener used to dispatch click events.
protected			OnFocusChangeListener	mOnFocusChangeListener	Listener used to dispatch focus change events.
protected			int	mPaddingBottom	The bottom padding in pixels, that is the distance in pixels between the bottom edge of this view and the bottom edge of its content.
protected			int	mPaddingLeft	The left padding in pixels, that is the distance in pixels between the left edge of this view and the left edge of its content.
protected			int	mPaddingRight	The right padding in pixels, that is the distance in pixels between the right edge of this view and the right edge of its content.
protected			int	mPaddingTop	The top padding in pixels, that is the distance in pixels between the top edge of this view and the top edge of its content.
protected			ViewParent	mParent	The parent this view is attached to.
protected			int	mRight	The distance in pixels from the right edge of this view’s parent to the right edge of this view.
protected			int	mScrollX	The offset, in pixels, by which the content of this view is scrolled horizontally.
protected			int	mScrollY	The offset, in pixels, by which the content of this view is scrolled vertically.
protected			Object	mTag	The view’s tag.
protected			int	mTop	The distance in pixels from the top edge of this view’s parent to the top edge of this view.
protected			int	mWindowLeft	The distance in pixels from the left edge of this view’s enclosing window to the left edge of this view.
protected			int	mWindowTop	The distance in pixels from the top edge of this view’s enclosing window to the top edge of this view.

Public Constructors

					CheckBox(Context context)
					CheckBox(Context context, AttributeSet attrs, Map inflateParams)
					CheckBox(Context context, AttributeSet attrs, Map inflateParams, int defStyle)

Methods inherited from class android.widget.CompoundButton

isChecked, onDraw, onKeyDown, performClick, setButtonDrawable, setButtonDrawable, setChecked, setOnCheckedChangeListener, toggle

				boolean	isChecked()
				void	onDraw(Canvas canvas)
					Implement this to do your drawing.
				boolean	onKeyDown(int keyCode, KeyEvent event)
					Called when a key down event has occurred.
				boolean	performClick()
					Call this view’s OnClickListener, if it is defined.
				void	setButtonDrawable(int resid)
					Set the background to a given Drawable, identified by its resource id.
				void	setButtonDrawable(Drawable d)
					Set the background to a given Drawable
				void	setChecked(boolean checked)
					Changes the checked state of this button.
				void	setOnCheckedChangeListener(OnCheckedChangeListener listener)
					Register a callback to be invoked when the checked state of this button changes.
				void	toggle()

Methods inherited from class android.widget.Button

createDrawableState, onMotionEvent, performClick

				int[]	createDrawableState()
					Generate the new drawable state for this view.
				boolean	onMotionEvent(MotionEvent ev)
					Implement this method to handle MotionEvent events.
				boolean	performClick()
					Call this view’s OnClickListener, if it is defined.

Methods inherited from class android.widget.TextView

addTextChangedListener, append, append, computeHorizontalScrollRange, computeScroll, computeVerticalScrollRange, debug, getBaseline, getDisabledTextColor, getFilters, getFocusedTextColor, getHintTextColor, getInputMethod, getInterestingRect, getLayout, getLineBounds, getLineCount, getLineHeight, getMovementMethod, getNormalTextColor, getPaint, getPaintFlags, getSelectedTextColor, getText, getTextScaleX, getTextSize, getTransformationMethod, getTypeface, length, onDraw, onFocusChanged, onKeyDown, onKeyUp, onMeasure, onTextChanged, restoreState, saveState, saveStateAndText, setAlignment, setCursorVisible, setDisabledTextColor, setEms, setFilters, setFocusedTextColor, setGravity, setHeight, setHiliteColor, setHint, setHint, setHintTextColor, setHorizontallyScrolling, setIncludeFontPadding, setInputMethod, setLineSpacing, setLines, setMaxEms, setMaxHeight, setMaxLines, setMaxWidth, setMinEms, setMinHeight, setMinLines, setMinWidth, setMovementMethod, setNormalTextColor, setPadding, setPaintFlags, setScroller, setSelectAllOnFocus, setSelectedTextColor, setShadowLayer, setSingleLine, setSingleLine, setText, setText, setText, setText, setText, setText, setTextColor, setTextScaleX, setTextSize, setTextSize, setTransformationMethod, setTypeface, setWidth, windowFocusChanged

				void	addTextChangedListener(TextWatcher watcher)
					Adds a TextWatcher to the list of those whose methods are called whenever this TextView’s text changes.
		final		void	append(CharSequence text)
					Convenience method: Append the specified text to the TextView’s display buffer, upgrading it to BufferType.EDITABLE if it was not already editable.
				void	append(CharSequence text, int start, int end)
					Convenience method: Append the specified text slice to the TextView’s display buffer, upgrading it to BufferType.EDITABLE if it was not already editable.
				int	computeHorizontalScrollRange()
					Compute the horizontal range that the horizontal scrollbar represents.
				void	computeScroll()
					Called by a parent to request that a child update its values for mScrollX and mScrollY if necessary.
				int	computeVerticalScrollRange()
					Compute the vertical range that the vertical scrollbar represents.
				void	debug(int depth)
					Prints information about this view in the log output, with the tag VIEW_LOG_TAG.
				int	getBaseline()
					Return the offset of the widget’s text baseline from the widget’s top boundary.
				int	getDisabledTextColor()
				InputFilter[]	getFilters()
					Returns the current list of input filters.
				int	getFocusedTextColor()
		final		int	getHintTextColor()
					Return the color used to paint the hint text.
		final		InputMethod	getInputMethod()
				void	getInterestingRect(Rect r)
					The rectangle that this view would like to make visible if it is being scrolled within its parent.
		final		Layout	getLayout()
				int	getLineBounds(int line, Rect bounds)
					Return the baseline for the specified line (0…getLineCount() - 1) If bounds is not null, return the top, left, right, bottom extents of the specified line in it.
				int	getLineCount()
					Return the number of lines of text, or 0 if the internal Layout has not been built.
				int	getLineHeight()
		final		MovementMethod	getMovementMethod()
				int	getNormalTextColor()
				Paint	getPaint()
				int	getPaintFlags()
				int	getSelectedTextColor()
				CharSequence	getText()
					Return the text the TextView is displaying.
				float	getTextScaleX()
				float	getTextSize()
		final		TransformationMethod	getTransformationMethod()
				Typeface	getTypeface()
				int	length()
					Returns the length, in characters, of the text managed by this TextView
				void	onDraw(Canvas canvas)
					Implement this to do your drawing.
				void	onFocusChanged(boolean focused, int direction)
					Called by the view system when the focus state of this view changes.
				boolean	onKeyDown(int keyCode, KeyEvent event)
					Called when a key down event has occurred.
				boolean	onKeyUp(int keyCode, KeyEvent event)
					Called when a key up event has occurred.
				void	onMeasure(int widthMeasureSpec, int heightMeasureSpec)
					Measure the view and its content to determine the measured width and the measured height.
				void	onTextChanged(CharSequence text, int start, int before, int after)
					This method is called when the text is changed, in case any subclasses would like to know.
				boolean	restoreState(Bundle state)
				Bundle	saveState()
				Bundle	saveStateAndText()
				void	setAlignment(Alignment align)
					Sets the alignment of this view’s text.
				void	setCursorVisible(boolean visible)
					Set whether the cursor is visible.
				void	setDisabledTextColor(int color)
					Sets the text color for this View when it is disabled.
				void	setEms(int ems)
					Makes the TextView exactly this many ems wide
				void	setFilters(InputFilter[] filters)
					Sets the list of input filters that will be used if the buffer is Editable.
				void	setFocusedTextColor(int color)
					Sets the text color for this text view when it has focus.
				void	setGravity(int gravity)
					Sets the vertical gravity that will be used when there is extra space in the TextView beyond what is required for the text itself.
				void	setHeight(int pixels)
					Makes the TextView exactly this many pixels tall.
				void	setHiliteColor(int color)
					Sets the color used to display the selection highlight.
		final		void	setHint(CharSequence hint)
					Sets the text to be displayed when the text of the TextView is empty.
		final		void	setHint(int resid)
					Sets the text to be displayed when the text of the TextView is empty, from a resource.
		final		void	setHintTextColor(int color)
					Sets the color of the hint text.
				void	setHorizontallyScrolling(boolean whether)
					Sets whether the text should be allowed to be wider than the View is.
				void	setIncludeFontPadding(boolean includepad)
					Set whether the TextView includes extra top and bottom padding to make room for accents that go above the normal ascent and descent.
				void	setInputMethod(InputMethod input)
					Sets the input method to be used with this TextView.
				void	setLineSpacing(float add, float mult)
					Sets line spacing for this TextView.
				void	setLines(int lines)
					Makes the TextView exactly this many lines tall
				void	setMaxEms(int maxems)
					Makes the TextView at most this many ems wide
				void	setMaxHeight(int maxHeight)
					Makes the TextView at most this many pixels tall
				void	setMaxLines(int maxlines)
					Makes the TextView at most this many lines tall
				void	setMaxWidth(int maxpixels)
					Makes the TextView at most this many pixels wide
				void	setMinEms(int minems)
					Makes the TextView at least this many ems wide
				void	setMinHeight(int minHeight)
					Makes the TextView at least this many pixels tall
				void	setMinLines(int minlines)
					Makes the TextView at least this many lines tall
				void	setMinWidth(int minpixels)
					Makes the TextView at least this many pixels wide
		final		void	setMovementMethod(MovementMethod movement)
					Sets the movement method (arrow key handler) to be used for this TextView.
				void	setNormalTextColor(int color)
					Sets the text color for this View when it is unfocused and not selected.
				void	setPadding(int left, int top, int right, int bottom)
					Sets the padding.
				void	setPaintFlags(int flags)
					Sets flags on the Paint being used to display the text and reflows the text if they are different from the old flags.
				void	setScroller(Scroller s)
				void	setSelectAllOnFocus(boolean selectAllOnFocus)
					Set the TextView so that when it takes focus, all the text is selected.
				void	setSelectedTextColor(int color)
					Sets the text color for this text view when it has been selected.
				void	setShadowLayer(float radius, float dx, float dy, int color)
					Gives the text a shadow of the specified radius and color, the specified distance from its normal position.
				void	setSingleLine()
					Sets the properties of this field (lines, horizontally scrolling, transformation method) to be for a single-line input.
				void	setSingleLine(boolean singleLine)
					If true, sets the properties of this field (lines, horizontally scrolling, transformation method) to be for a single-line input; if false, restores these to the default conditions.
		final		void	setText(int resid)
		final		void	setText(int resid, BufferType type)
		final		void	setText(Cursor cursor, int column, BufferType type)
		final		void	setText(CharSequence text)
				void	setText(CharSequence text, BufferType type)
					Sets the text that this TextView is to display (see setText(CharSequence)) and also sets whether it is stored in a styleable/spannable buffer and whether it is editable.
		final		void	setText(Cursor cursor, int column)
				void	setTextColor(int color)
					Set the text color for all the states (normal, selected, focused) to be this color.
				void	setTextScaleX(float size)
					Sets the extent by which text should be stretched horizontally.
				void	setTextSize(int unit, float size)
					Set the default text size to a given unit and value.
				void	setTextSize(float size)
					Set the default text size to the given value, interpreted as “scaled pixel” units.
		final		void	setTransformationMethod(TransformationMethod method)
					Sets the transformation that is applied to the text that this TextView is displaying.
				void	setTypeface(Typeface tf)
					Sets the typeface and style in which the text should be displayed.
				void	setWidth(int pixels)
					Makes the TextView exactly this many pixels wide.
				void	windowFocusChanged(boolean hasWindowFocus)
					Called when the window containing this view gains or loses focus.

Methods inherited from class android.view.View

awakenScrollBars, awakenScrollBars, bringToFront, clearAnimation, clearFocus, computeHorizontalScrollExtent, computeHorizontalScrollOffset, computeHorizontalScrollRange, computeScroll, computeVerticalScrollExtent, computeVerticalScrollOffset, computeVerticalScrollRange, copyWindowBitmap, createDrawableState, debug, debug, debugIndent, dispatchDraw, dispatchKeyEvent, dispatchMotionEvent, dispatchUnhandledMove, dispatchWindowFocusChanged, draw, drawableStateChanged, findFocus, findParentViewOfType, findViewById, findViewWithTag, focusSearch, focusSearchInDescendants, forceLayout, getAbsoluteLocationOnScreen, getBackground, getBaseline, getBlockDescendantFocus, getBlockUnmatchedKeyUps, getBottom, getContext, getCurrentAnimation, getDefaultSize, getDrawableState, getDrawingRect, getDrawingTime, getFocusType, getFocusables, getGlobalVisibleRect, getGlobalVisibleRect, getHeight, getHitRect, getHorizontalFadingEdgeLength, getId, getInterestingRect, getLayoutParams, getLeft, getLocalVisibleRect, getLocationOnScreen, getMeasuredHeight, getMeasuredWidth, getOnFocusChangeListener, getPaddingBottom, getPaddingLeft, getPaddingRight, getPaddingTop, getParent, getResources, getRight, getRootView, getScrollX, getScrollY, getTag, getTop, getVerticalFadingEdgeLength, getVisibility, getWidth, getWindowBottom, getWindowFrame, getWindowLeft, getWindowRight, getWindowSession, getWindowToken, getWindowTop, hasBackground, hasFocus, hasWindowFocus, initializeFadingEdge, initializeScrollbars, invalidate, invalidate, invalidate, invalidateDrawable, isEnabled, isFocusable, isFocused, isHorizontalFadingEdgeEnabled, isHorizontalScrollBarEnabled, isLayoutRequested, isSelected, isVerticalFadingEdgeEnabled, isVerticalScrollBarEnabled, layout, measure, offsetLeftAndRight, offsetTopAndBottom, onAttachedToWindow, onDetachedFromWindow, onDraw, onDrawAfterChildren, onDrawBackground, onFinishInflate, onFocusChanged, onKeyDown, onKeyUp, onLayout, onMeasure, onMotionEvent, onScrollChanged, onSizeChanged, performClick, postInvalidate, postInvalidateDelayed, refreshDrawableState, requestFocus, requestFocus, requestLayout, requestRectangleOnScreen, resolveSize, scheduleDrawable, scrollBy, scrollTo, setBackground, setBackground, setBackgroundColor, setBlockDescendantFocus, setBlockUnmatchedKeyUps, setCurrentAnimation, setEnabled, setFocusType, setFocusable, setHorizontalFadingEdgeEnabled, setHorizontalScrollBarEnabled, setId, setKeyListener, setLayoutParams, setMeasuredDimension, setOnClickListener, setOnFocusChangeListener, setPadding, setPreferredHeight, setPreferredWidth, setSelected, setTag, setVerticalFadingEdgeEnabled, setVerticalScrollBarEnabled, setVisibility, setWillNotDraw, startAnimation, takeFocus, unscheduleDrawable, unscheduleDrawable, verifyDrawable, willNotDraw, windowFocusChanged

				boolean	awakenScrollBars(int startDelay)
					Trigger the scrollbars to draw.
				boolean	awakenScrollBars()
					Trigger the scrollbars to draw.
				void	bringToFront()
					Change the view’s z order in the tree, so it’s on top of other sibling views
				void	clearAnimation()
					Cancels any animations for this view.
				void	clearFocus()
					Called when this view wants to give up focus.
				int	computeHorizontalScrollExtent()
					Compute the horizontal extent of the horizontal scrollbar’s thumb within the horizontal range.
				int	computeHorizontalScrollOffset()
					Compute the horizontal offset of the horizontal scrollbar’s thumb within the horizontal range.
				int	computeHorizontalScrollRange()
					Compute the horizontal range that the horizontal scrollbar represents.
				void	computeScroll()
					Called by a parent to request that a child update its values for mScrollX and mScrollY if necessary.
				int	computeVerticalScrollExtent()
					Compute the vertical extent of the horizontal scrollbar’s thumb within the vertical range.
				int	computeVerticalScrollOffset()
					Compute the vertical offset of the vertical scrollbar’s thumb within the horizontal range.
				int	computeVerticalScrollRange()
					Compute the vertical range that the vertical scrollbar represents.
				Bitmap	copyWindowBitmap()
					Return a copy of the bitmap holding the overall contents of the window this view is attached to.
				int[]	createDrawableState()
					Generate the new drawable state for this view.
				void	debug()
					Prints information about this view in the log output, with the tag VIEW_LOG_TAG.
				void	debug(int depth)
					Prints information about this view in the log output, with the tag VIEW_LOG_TAG.
			static	String	debugIndent(int depth)
					Creates an string of whitespaces used for indentation.
				void	dispatchDraw(Canvas<