freemarker.ext.jsp.FreeMarkerPageContext Maven / Gradle / Ivy
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Google App Engine compliant variation of FreeMarker.
FreeMarker is a "template engine"; a generic tool to generate text output based on templates.
/*
* Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package freemarker.ext.jsp;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.ListIterator;
import javax.servlet.GenericServlet;
import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import javax.servlet.http.HttpSession;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.BodyContent;
import freemarker.core.Environment;
import freemarker.ext.servlet.FreemarkerServlet;
import freemarker.ext.servlet.HttpRequestHashModel;
import freemarker.ext.servlet.ServletContextHashModel;
import freemarker.ext.util.WrapperTemplateModel;
import freemarker.template.AdapterTemplateModel;
import freemarker.template.ObjectWrapper;
import freemarker.template.TemplateBooleanModel;
import freemarker.template.TemplateHashModelEx;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
import freemarker.template.TemplateModelIterator;
import freemarker.template.TemplateNumberModel;
import freemarker.template.TemplateScalarModel;
import freemarker.template.utility.UndeclaredThrowableException;
/**
*/
abstract class FreeMarkerPageContext extends PageContext implements TemplateModel
{
private static final Class OBJECT_CLASS = Object.class;
private final Environment environment;
private List tags = new ArrayList();
private List outs = new ArrayList();
private final GenericServlet servlet;
private HttpSession session;
private final HttpServletRequest request;
private final HttpServletResponse response;
private final ObjectWrapper wrapper;
private JspWriter jspOut;
protected FreeMarkerPageContext() throws TemplateModelException
{
environment = Environment.getCurrentEnvironment();
TemplateModel appModel = environment.getGlobalVariable(
FreemarkerServlet.KEY_APPLICATION_PRIVATE);
if(!(appModel instanceof ServletContextHashModel)) {
appModel = environment.getGlobalVariable(
FreemarkerServlet.KEY_APPLICATION);
}
if(appModel instanceof ServletContextHashModel) {
this.servlet = ((ServletContextHashModel)appModel).getServlet();
}
else {
throw new TemplateModelException("Could not find an instance of " +
ServletContextHashModel.class.getName() +
" in the data model under either the name " +
FreemarkerServlet.KEY_APPLICATION_PRIVATE + " or " +
FreemarkerServlet.KEY_APPLICATION);
}
TemplateModel requestModel =
environment.getGlobalVariable(FreemarkerServlet.KEY_REQUEST_PRIVATE);
if(!(requestModel instanceof HttpRequestHashModel)) {
requestModel = environment.getGlobalVariable(
FreemarkerServlet.KEY_REQUEST);
}
if(requestModel instanceof HttpRequestHashModel) {
HttpRequestHashModel reqHash = (HttpRequestHashModel)requestModel;
this.request = reqHash.getRequest();
this.session = request.getSession(false);
this.response = reqHash.getResponse();
this.wrapper = reqHash.getObjectWrapper();
}
else {
throw new TemplateModelException("Could not find an instance of " +
HttpRequestHashModel.class.getName() +
" in the data model under either the name " +
FreemarkerServlet.KEY_REQUEST_PRIVATE + " or " +
FreemarkerServlet.KEY_REQUEST);
}
// Register page attributes as per spec
setAttribute(REQUEST, request);
setAttribute(RESPONSE, response);
if (session != null)
setAttribute(SESSION, session);
setAttribute(PAGE, servlet);
setAttribute(CONFIG, servlet.getServletConfig());
setAttribute(PAGECONTEXT, this);
setAttribute(APPLICATION, servlet.getServletContext());
}
ObjectWrapper getObjectWrapper() {
return wrapper;
}
public void initialize(
Servlet servlet, ServletRequest request, ServletResponse response,
String errorPageURL, boolean needsSession, int bufferSize,
boolean autoFlush)
{
throw new UnsupportedOperationException();
}
public void release() {
}
public void setAttribute(String name, Object value) {
setAttribute(name, value, PAGE_SCOPE);
}
public void setAttribute(String name, Object value, int scope) {
switch(scope) {
case PAGE_SCOPE: {
try {
environment.setGlobalVariable(name, wrapper.wrap(value));
break;
}
catch(TemplateModelException e) {
throw new UndeclaredThrowableException(e);
}
}
case REQUEST_SCOPE: {
getRequest().setAttribute(name, value);
break;
}
case SESSION_SCOPE: {
getSession(true).setAttribute(name, value);
break;
}
case APPLICATION_SCOPE: {
getServletContext().setAttribute(name, value);
break;
}
default: {
throw new IllegalArgumentException("Invalid scope " + scope);
}
}
}
public Object getAttribute(String name)
{
return getAttribute(name, PAGE_SCOPE);
}
public Object getAttribute(String name, int scope)
{
switch (scope) {
case PAGE_SCOPE: {
try {
TemplateModel m = environment.getGlobalNamespace().get(name);
if (m instanceof AdapterTemplateModel) {
return ((AdapterTemplateModel) m).getAdaptedObject(OBJECT_CLASS);
}
if (m instanceof WrapperTemplateModel) {
return ((WrapperTemplateModel)m).getWrappedObject();
}
if (m instanceof TemplateScalarModel) {
return ((TemplateScalarModel) m).getAsString();
}
if (m instanceof TemplateNumberModel) {
return ((TemplateNumberModel) m).getAsNumber();
}
if (m instanceof TemplateBooleanModel) {
return Boolean.valueOf(((TemplateBooleanModel) m).getAsBoolean());
}
return m;
}
catch (TemplateModelException e) {
throw new UndeclaredThrowableException(e);
}
}
case REQUEST_SCOPE: {
return getRequest().getAttribute(name);
}
case SESSION_SCOPE: {
HttpSession session = getSession(false);
if(session == null) {
return null;
}
return session.getAttribute(name);
}
case APPLICATION_SCOPE: {
return getServletContext().getAttribute(name);
}
default: {
throw new IllegalArgumentException("Invalid scope " + scope);
}
}
}
public Object findAttribute(String name)
{
Object retval = getAttribute(name, PAGE_SCOPE);
if(retval != null) return retval;
retval = getAttribute(name, REQUEST_SCOPE);
if(retval != null) return retval;
retval = getAttribute(name, SESSION_SCOPE);
if(retval != null) return retval;
return getAttribute(name, APPLICATION_SCOPE);
}
public void removeAttribute(String name) {
removeAttribute(name, PAGE_SCOPE);
removeAttribute(name, REQUEST_SCOPE);
removeAttribute(name, SESSION_SCOPE);
removeAttribute(name, APPLICATION_SCOPE);
}
public void removeAttribute(String name, int scope) {
switch(scope) {
case PAGE_SCOPE: {
environment.getGlobalNamespace().remove(name);
break;
}
case REQUEST_SCOPE: {
getRequest().removeAttribute(name);
break;
}
case SESSION_SCOPE: {
HttpSession session = getSession(false);
if(session != null) {
session.removeAttribute(name);
}
break;
}
case APPLICATION_SCOPE: {
getServletContext().removeAttribute(name);
break;
}
default: {
throw new IllegalArgumentException("Invalid scope: " + scope);
}
}
}
public int getAttributesScope(String name) {
if(getAttribute(name, PAGE_SCOPE) != null) return PAGE_SCOPE;
if(getAttribute(name, REQUEST_SCOPE) != null) return REQUEST_SCOPE;
if(getAttribute(name, SESSION_SCOPE) != null) return SESSION_SCOPE;
if(getAttribute(name, APPLICATION_SCOPE) != null) return APPLICATION_SCOPE;
return 0;
}
public Enumeration getAttributeNamesInScope(int scope) {
switch(scope) {
case PAGE_SCOPE: {
try {
return
new TemplateHashModelExEnumeration(environment.getGlobalNamespace());
}
catch(TemplateModelException e) {
throw new UndeclaredThrowableException(e);
}
}
case REQUEST_SCOPE: {
return getRequest().getAttributeNames();
}
case SESSION_SCOPE: {
HttpSession session = getSession(false);
if(session != null) {
return session.getAttributeNames();
}
return Collections.enumeration(Collections.EMPTY_SET);
}
case APPLICATION_SCOPE: {
return getServletContext().getAttributeNames();
}
default: {
throw new IllegalArgumentException("Invalid scope " + scope);
}
}
}
public JspWriter getOut() {
return jspOut;
}
private HttpSession getSession(boolean create) {
if(session == null) {
session = request.getSession(create);
if(session != null) {
setAttribute(SESSION, session);
}
}
return session;
}
public HttpSession getSession() {
return getSession(false);
}
public Object getPage() {
return servlet;
}
public ServletRequest getRequest() {
return request;
}
public ServletResponse getResponse() {
return response;
}
public Exception getException() {
throw new UnsupportedOperationException();
}
public ServletConfig getServletConfig() {
return servlet.getServletConfig();
}
public ServletContext getServletContext() {
return servlet.getServletContext();
}
public void forward(String url) throws ServletException, IOException {
//TODO: make sure this is 100% correct by looking at Jasper output
request.getRequestDispatcher(url).forward(request, response);
}
public void include(String url) throws ServletException, IOException {
jspOut.flush();
request.getRequestDispatcher(url).include(request, response);
}
public void include(String url, boolean flush) throws ServletException, IOException {
if(flush) {
jspOut.flush();
}
final PrintWriter pw = new PrintWriter(jspOut);
request.getRequestDispatcher(url).include(request, new HttpServletResponseWrapper(response) {
public PrintWriter getWriter() {
return pw;
}
public ServletOutputStream getOutputStream() {
throw new UnsupportedOperationException("JSP-included resource must use getWriter()");
}
});
pw.flush();
}
public void handlePageException(Exception e) {
throw new UnsupportedOperationException();
}
public void handlePageException(Throwable e) {
throw new UnsupportedOperationException();
}
public BodyContent pushBody() {
return (BodyContent)pushWriter(new TagTransformModel.BodyContentImpl(getOut(), true));
}
public JspWriter pushBody(Writer w) {
return pushWriter(new JspWriterAdapter(w));
}
public JspWriter popBody() {
popWriter();
return (JspWriter) getAttribute(OUT);
}
Object peekTopTag(Class tagClass) {
for (ListIterator iter = tags.listIterator(tags.size()); iter.hasPrevious();)
{
Object tag = iter.previous();
if(tagClass.isInstance(tag)) {
return tag;
}
}
return null;
}
void popTopTag() {
tags.remove(tags.size() - 1);
}
void popWriter() {
jspOut = (JspWriter)outs.remove(outs.size() - 1);
setAttribute(OUT, jspOut);
}
void pushTopTag(Object tag) {
tags.add(tag);
}
JspWriter pushWriter(JspWriter out) {
outs.add(jspOut);
jspOut = out;
setAttribute(OUT, jspOut);
return out;
}
private static class TemplateHashModelExEnumeration implements Enumeration {
private final TemplateModelIterator it;
private TemplateHashModelExEnumeration(TemplateHashModelEx hashEx) throws TemplateModelException {
it = hashEx.keys().iterator();
}
public boolean hasMoreElements() {
try {
return it.hasNext();
} catch (TemplateModelException tme) {
throw new UndeclaredThrowableException(tme);
}
}
public Object nextElement() {
try {
return ((TemplateScalarModel) it.next()).getAsString();
} catch (TemplateModelException tme) {
throw new UndeclaredThrowableException(tme);
}
}
}
}