package org.jboss.resteasy.jsapi;
import org.jboss.resteasy.jsapi.i18n.LogMessages;
import org.jboss.resteasy.jsapi.i18n.Messages;
import org.jboss.resteasy.util.PathHelper;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.zip.GZIPOutputStream;
/**
* @author Stéphane Épardaud <stef@epardaud.fr>
*/
public class JSAPIWriter
{
private static final long serialVersionUID = -1985015444704126795L;
public void writeJavaScript(String base, HttpServletRequest req, HttpServletResponse resp,
Map<String, ServiceRegistry> serviceRegistries) throws IOException
{
LogMessages.LOGGER.debug(Messages.MESSAGES.startResteasyClient());
// RESTEASY-776
// before writing generated javascript, we generate Etag and compare it with client request.
// If nothing changed, we send back 304 Not Modified for client browser to use cached js.
String ifNoneMatch = req.getHeader("If-None-Match");
String etag = generateEtag(serviceRegistries);
resp.setHeader("Etag", etag);
if (ifNoneMatch != null && ifNoneMatch.equals(etag))
{
resp.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
return;
}
for (Map.Entry<String, ServiceRegistry> entry : serviceRegistries.entrySet())
{
String uri = base;
if (entry.getKey() != null) uri += entry.getKey();
StringWriter stringWriter = new StringWriter();
PrintWriter writer = new PrintWriter(new BufferedWriter(stringWriter));
writeJavaScript(uri, writer, entry.getValue());
writer.flush();
writer.close();
if (clientIsGzipSupported(req))
{
ByteArrayOutputStream compressedContent = new ByteArrayOutputStream();
GZIPOutputStream gzipstream = new GZIPOutputStream(compressedContent);
gzipstream.write(stringWriter.toString().getBytes());
gzipstream.finish();
// get the compressed content
byte[] compressedBytes = compressedContent.toByteArray();
// set appropriate HTTP headers
resp.setContentLength(compressedBytes.length);
resp.addHeader("Content-Encoding", "gzip");
ServletOutputStream output = resp.getOutputStream();
output.write(compressedBytes);
output.flush();
output.close();
}
else
{
ServletOutputStream output = resp.getOutputStream();
byte[] bytes = stringWriter.toString().getBytes();
resp.setContentLength(bytes.length);
output.write(bytes);
output.flush();
output.close();
}
}
}
private boolean clientIsGzipSupported(HttpServletRequest req)
{
String encoding = req.getHeader("Accept-Encoding");
return encoding != null && encoding.contains("gzip");
}
public void writeJavaScript(String uri, PrintWriter writer,
ServiceRegistry serviceRegistry) throws IOException
{
copyResource("/resteasy-client.js", writer);
LogMessages.LOGGER.debug(Messages.MESSAGES.startJaxRsApi());
LogMessages.LOGGER.debug(Messages.MESSAGES.restApiUrl(uri));
writer.println("REST.apiURL = '" + uri + "';");
Set<String> declaredPrefixes = new HashSet<String>();
printService(writer, serviceRegistry, declaredPrefixes);
}
private String generateEtag(Map<String, ServiceRegistry> serviceRegistries)
{
StringBuilder etagBuilder = new StringBuilder();
for (Map.Entry<String, ServiceRegistry> entry : serviceRegistries.entrySet())
{
if (entry.getKey() != null) etagBuilder.append(entry.getKey()).append(':');
generateEtag(entry.getValue(), etagBuilder);
}
return String.valueOf(Math.abs(etagBuilder.toString().hashCode()));
}
private void generateEtag(ServiceRegistry serviceRegistry, StringBuilder etagBuilder)
{
for (MethodMetaData methodMetaData : serviceRegistry.getMethodMetaData())
{
etagBuilder.append(methodMetaData.hashCode());
for (ServiceRegistry subService : serviceRegistry.getLocators())
{
generateEtag(subService, etagBuilder);
}
}
}
private void printService(PrintWriter writer,
ServiceRegistry serviceRegistry, Set<String> declaredPrefixes)
{
for (MethodMetaData methodMetaData : serviceRegistry.getMethodMetaData())
{
LogMessages.LOGGER.debug(Messages.MESSAGES.path(methodMetaData.getUri()));
LogMessages.LOGGER.debug(Messages.MESSAGES.invoker(methodMetaData.getInvoker()));
String declaringPrefix = methodMetaData.getFunctionPrefix(); // TODO Add prefix path segment
declarePrefix(writer, declaringPrefix, declaredPrefixes);
for (String httpMethod : methodMetaData.getHttpMethods())
{
print(writer, httpMethod, methodMetaData);
}
}
for (ServiceRegistry subService : serviceRegistry.getLocators())
printService(writer, subService, declaredPrefixes);
}
private void declarePrefix(PrintWriter writer, String declaringPrefix, Set<String> declaredPrefixes)
{
if (declaredPrefixes.add(declaringPrefix))
{
int lastDot = declaringPrefix.lastIndexOf(".");
if (lastDot == -1)
writer.println("var " + declaringPrefix + " = {};");
else
{
declarePrefix(writer, declaringPrefix.substring(0, lastDot), declaredPrefixes);
writer.println(declaringPrefix + " = {};");
}
}
}
private void copyResource(String name, PrintWriter writer)
throws IOException
{
Reader reader = new InputStreamReader(getClass()
.getResourceAsStream(name));
char[] array = new char[1024];
int read;
while ((read = reader.read(array)) >= 0)
{
writer.write(array, 0, read);
}
reader.close();
}
private void print(PrintWriter writer, String httpMethod,
MethodMetaData methodMetaData)
{
String uri = methodMetaData.getUri();
writer.println("// " + httpMethod + " " + uri);
writer
.println(methodMetaData.getFunctionName() + " = function(_params){");
writer.println(" var params = _params ? _params : {};");
writer.println(" var request = new REST.Request();");
writer.println(" request.setMethod('" + httpMethod + "');");
writer
.println(" var uri = params.$apiURL ? params.$apiURL : REST.apiURL;");
if (uri.contains("{"))
{
printURIParams(uri, writer);
}
else
{
writer.println(" uri += '" + uri + "';");
}
printOtherParams(methodMetaData, writer);
writer.println(" request.setURI(uri);");
writer.println(" if(params.$username && params.$password)");
writer
.println(" request.setCredentials(params.$username, params.$password);");
writer.println(" if(params.$accepts)");
writer.println(" request.setAccepts(params.$accepts);");
if (methodMetaData.getWants() != null)
{
writer.println(" else");
writer.println(" request.setAccepts('" + methodMetaData.getWants()
+ "');");
}
writer.println("if (REST.antiBrowserCache == true) {");
writer.println(" request.addQueryParameter('resteasy_jsapi_anti_cache', (new Date().getTime()));");
writer.println(" var cached_obj = REST._get_cache_signature(REST._generate_cache_signature(uri));");
writer.println(" if (cached_obj != null) { request.addHeader('If-Modified-Since', cached_obj[1]['Last-Modified']); request.addHeader('If-None-Match', cached_obj[1]['Etag']);}");
writer.println("}");
writer.println(" if(params.$contentType)");
writer.println(" request.setContentType(params.$contentType);");
writer.println(" else");
writer.println(" request.setContentType('"
+ methodMetaData.getConsumesMIMEType() + "');");
writer.println(" if(params.$callback){");
writer.println(" request.execute(params.$callback);");
writer.println(" }else{");
writer.println(" var returnValue;");
writer.println(" request.setAsync(false);");
writer
.println(" var callback = function(httpCode, xmlHttpRequest, value){ returnValue = value;};");
writer.println(" request.execute(callback);");
writer.println(" return returnValue;");
writer.println(" }");
writer.println("};");
}
private void printOtherParams(MethodMetaData methodMetaData,
PrintWriter writer)
{
List<MethodParamMetaData> params = methodMetaData.getParameters();
for (MethodParamMetaData methodParamMetaData : params)
{
printParameter(methodParamMetaData, writer);
}
}
private void printParameter(MethodParamMetaData metaData,
PrintWriter writer)
{
switch (metaData.getParamType())
{
case QUERY_PARAMETER:
print(metaData, writer, "QueryParameter");
break;
case HEADER_PARAMETER:
print(metaData, writer, "Header");
// FIXME: warn about forbidden headers:
// http://www.w3.org/TR/XMLHttpRequest/#the-setrequestheader-method
break;
case COOKIE_PARAMETER:
print(metaData, writer, "Cookie");
break;
case MATRIX_PARAMETER:
print(metaData, writer, "MatrixParameter");
break;
case FORM_PARAMETER:
print(metaData, writer, "FormParameter");
break;
case FORM:
print(metaData, writer, "Form");
break;
case ENTITY_PARAMETER:
// the entity
writer.println(" if(params.$entity)");
writer.println(" request.setEntity(params.$entity);");
break;
}
}
private void print(MethodParamMetaData metaData, PrintWriter writer,
String type)
{
String paramName = metaData.getParamName();
writer.println(String.format(" if(Object.prototype.hasOwnProperty.call(params, '%s'))\n request.add%s('%s', params.%s);", paramName, type, paramName, paramName));
}
private void printURIParams(String uri, PrintWriter writer)
{
String replacedCurlyURI = PathHelper.replaceEnclosedCurlyBraces(uri);
Matcher matcher = PathHelper.URI_PARAM_PATTERN.matcher(replacedCurlyURI);
int i = 0;
while (matcher.find())
{
if (matcher.start() > i)
{
writer.println(" uri += '"
+ replacedCurlyURI.substring(i, matcher.start()) + "';");
}
String name = matcher.group(1);
writer.println(" uri += REST.Encoding.encodePathSegment(params." + name + ");");
i = matcher.end();
}
if (i < replacedCurlyURI.length())
writer.println(" uri += '" + replacedCurlyURI.substring(i) + "';");
}
}