JspImpl.java

package net.sf.jsptest.compiler.jsp20;

import java.util.Map;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.servlet.jsp.JspFactory;

import net.sf.jsptest.compiler.api.Jsp;
import net.sf.jsptest.compiler.api.JspExecution;
import net.sf.jsptest.compiler.jsp20.mock.MockHttpServletRequest;
import net.sf.jsptest.compiler.jsp20.mock.MockHttpServletResponse;
import net.sf.jsptest.compiler.jsp20.mock.MockHttpSession;
import net.sf.jsptest.compiler.jsp20.mock.MockJspFactory;
import net.sf.jsptest.compiler.jsp20.mock.MockJspWriter;
import net.sf.jsptest.compiler.jsp20.mock.MockPageContext;
import net.sf.jsptest.compiler.jsp20.mock.MockServletConfig;
import net.sf.jsptest.compiler.jsp20.mock.MockServletContext;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * @author Lasse Koskela
 * @author Ronaldo Webb
 */
public class JspImpl implements Jsp {

	private static final Log log = LogFactory.getLog(JspImpl.class);
	private final Class servletClass;
	private MockPageContext pageContext;

	public JspImpl(Class servletClass) {
		this.servletClass = servletClass;
	}

	public JspExecution request(String httpMethod, Map requestAttributes,
			Map sessionAttributes, Map requestParameters) {
		ServletContext servletContext = new MockServletContext();
		ServletConfig servletConfig = new MockServletConfig(servletContext);
		MockHttpSession session = configureHttpSession(sessionAttributes);
		MockHttpServletRequest request = configureHttpServletRequest(
				httpMethod, requestAttributes, requestParameters, session);
		MockHttpServletResponse response = new MockHttpServletResponse();
		MockJspWriter jspWriter = configureJspFactory(servletContext, request,
				session);
		initializeAndInvokeJsp(servletClass, servletConfig, request, response);
		return createExecutionResult(jspWriter.getContents());
	}

	private MockHttpSession configureHttpSession(Map sessionAttributes) {
		MockHttpSession httpSession = new MockHttpSession();
		httpSession.setAttributes(sessionAttributes);
		return httpSession;
	}

	private MockHttpServletRequest configureHttpServletRequest(
			String httpMethod, Map requestAttributes, Map requestParameters,
			MockHttpSession session) {
		MockHttpServletRequest request = new MockHttpServletRequest();
		request.setSession(session);
		request.setMethod(httpMethod);
		request.setAttributes(requestAttributes);
		request.setParameters(requestParameters);
		return request;
	}

	protected MockJspWriter configureJspFactory(ServletContext httpContext,
			HttpServletRequest httpRequest, HttpSession httpSession) {
		MockJspWriter jspWriter = new MockJspWriter();
		pageContext = configurePageContext(httpContext, httpRequest,
				httpSession, jspWriter);
		JspFactory.setDefaultFactory(new MockJspFactory(pageContext));
		return jspWriter;
	}

	private MockPageContext configurePageContext(ServletContext httpContext,
			HttpServletRequest httpRequest, HttpSession httpSession,
			MockJspWriter jspWriter) {
		MockPageContext pageContext = new MockPageContext();
		pageContext.setRequest(httpRequest);
		pageContext.setServletContext(httpContext);
		pageContext.setSession(httpSession);
		pageContext.setJspWriter(jspWriter);
		return pageContext;
	}

	protected void initializeAndInvokeJsp(Class jspClass,
			ServletConfig servletConfig, HttpServletRequest request,
			HttpServletResponse response) {
		try {
			log.debug("Instantiating Servlet: " + jspClass.getName());
			HttpServlet servlet = (HttpServlet) jspClass.newInstance();
			log.debug("Initializing Servlet: " + jspClass.getName());
			servlet.init(servletConfig);
			log.debug("Invoking Servlet: " + jspClass.getName());
			servlet.service(request, response);
			if (pageContext.getException() != null) {
				log.debug("An exception was stored into PageContext. Rethrowing it...");
				throw new RuntimeException(pageContext.getException());
			}
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	protected JspExecution createExecutionResult(String output) {
		return new JspExecutionImpl(output);
	}
}