Bug 156166 Error occour when previewing attached report in web viewer.
Decription:Error occour when previewing attached report in web viewer. Steps to reproduce: 1.run attached reports in web viewer. Expeceted results: preview properly Actual results: Error occour when previewing the reports in web viewer while it works properly in html and PDF
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/document/util/ExprDataReader2.java
private DataInputStream rowExprsDis;
	
	protected int rowCount;
	
	private int lastRowIndex;
	private int currRowIndex;
	
	private int currRowLenReadIndex;
	
	private RowIndexUtil rowIndexUtil;
	
	private int nextDestIndex; 
	
	private Map exprValueMap;	
	private Map rowIDMap;
	private List exprKeys;
	private int metaOffset;
	
	/**
	 * @param rowExprsIs
	 * @param rowLenIs
	 * @throws DataException 
	 */
	ExprDataReader2( RAInputStream rowExprsIs, RAInputStream rowLenIs ) throws DataException
	{
		try
		{
			
			IOUtil.readInt( rowExprsIs );