Bug 147407 Preview the attached report in the web viewer first time and then click the TOC button will cause NPE error
Description: It just can be reprouduced at first time preview. Step to reproduce: 1. please use attach report file 2. preview it in the web viewer 3. click the "Toggle table of contents" button Actual result: As the atteched screenshot shows,There is a NPE error.And if you preview it in the Web viewer again, the phenomenon is disappear.But reopen the eclipse and preview it at first time, it will be occured.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
import java.io.File;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import org.apache.axis.AxisFault;
import org.eclipse.birt.report.IBirtConstants;
/**
 * Utilites class for all types of URl related operatnios.
 * <p>
 */
public class ParameterAccessor
{
	
	/**
	 * Servlet path for parameter model.
	 */
	public static final String SERVLET_PATH_PARAMETER = "/parameter"; 
	/**
	 * Servlet path for preview model.
	 */