Mutable HttpServletRequest

MutableHttpServletRequest.java

public class MutableHttpServletRequest extends HttpServletRequestWrapper {
	
	private Map<String,String[]> parameters = new HashMap<String,String[]>();

	public MutableHttpServletRequest(HttpServletRequest request) {
		super(request);
	}

	public void setParameter(String name, String value) {
		parameters.put(name, new String[] {value});
	}

	@Override
	public String getParameter(String name) {
		if (parameters.get(name) != null) {
			return parameters.get(name)[0];
		}
		HttpServletRequest req = (HttpServletRequest) super.getRequest();
		return req.getParameter(name);
	}

	public Map<String, String[]> getParameterMap() {
		Map<String, String[]> result = new HashMap<String, String[]>();
		result.putAll(super.getRequest().getParameterMap());
		result.putAll(parameters);
		return Collections.<String, String[]>unmodifiableMap(result);
	}

	public Enumeration<String> getParameterNames() {
		Set<String> result = new HashSet<String>(Collections.list(super.getRequest().getAttributeNames()));
		result.addAll(parameters.keySet());
		return new Vector<String>(result).elements();
	}

	public String[] getParameterValues(String name) {
		if (parameters.get(name) != null) {
			return parameters.get(name);
		}
		HttpServletRequest req = (HttpServletRequest) super.getRequest();
		return req.getParameterValues(name);
	}
}

Nice