/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.shindig.gadgets.servlet;
import org.apache.commons.io.IOUtils;
import org.apache.shindig.common.servlet.InjectedServlet;
import org.json.JSONException;
import org.json.JSONObject;
import com.google.inject.Inject;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.regex.Pattern;
/**
* Handles RPC metadata requests.
*/
public class RpcServlet extends InjectedServlet {
static final String GET_REQUEST_REQ_PARAM = "req";
static final String GET_REQUEST_CALLBACK_PARAM = "callback";
// Starts with alpha or underscore, followed by alphanum, underscore or period
static final Pattern GET_REQUEST_CALLBACK_PATTERN = Pattern.compile("[A-Za-z_][A-Za-z0-9_\\.]+");
private static final int POST_REQUEST_MAX_SIZE = 1024 * 128;
private static final Logger logger = Logger.getLogger("org.apache.shindig.gadgets");
private JsonRpcHandler jsonHandler;
@Inject
public void setJsonRpcHandler(JsonRpcHandler jsonHandler) {
this.jsonHandler = jsonHandler;
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException {
String reqValue;
String callbackValue;
try {
reqValue = validateParameterValue(request, GET_REQUEST_REQ_PARAM);
callbackValue = validateParameterValue(request, GET_REQUEST_CALLBACK_PARAM);
if (!GET_REQUEST_CALLBACK_PATTERN.matcher(callbackValue).matches()) {
throw new IllegalArgumentException("Wrong format for parameter '" +
GET_REQUEST_CALLBACK_PARAM + "' specified. Expected: " +
GET_REQUEST_CALLBACK_PATTERN.toString());
}
} catch (IllegalArgumentException e) {
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
logger.log(Level.INFO, e.getMessage(), e);
return;
}
Result result = process(request, response, reqValue.getBytes());
response.getWriter().write(result.isSuccess()
? callbackValue + '(' + result.getOutput() + ')'
: result.getOutput());
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws IOException {
int length = request.getContentLength();
if (length <= 0) {
logger.info("No Content-Length specified.");
response.setStatus(HttpServletResponse.SC_LENGTH_REQUIRED);
return;
}
if (length > POST_REQUEST_MAX_SIZE) {
logger.info("Request size too large: " + length);
response.setStatus(HttpServletResponse.SC_REQUEST_ENTITY_TOO_LARGE);
return;
}
ServletInputStream is = request.getInputStream();
byte[] body = IOUtils.toByteArray(is);
if (body.length != length) {
logger.info("Wrong size. Length: " + length + " real: " + body.length);
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
return;
}
Result result = process(request, response, body);
response.getWriter().write(result.getOutput());
}
private String validateParameterValue(HttpServletRequest request, String parameter)
throws IllegalArgumentException {
String result = request.getParameter(parameter);
if (result == null) {
throw new IllegalArgumentException("No parameter '" + parameter + "' specified.");
}
return result;
}
private Result process(HttpServletRequest request, HttpServletResponse response, byte[] body) {
try {
String encoding = getRequestCharacterEncoding(request);
JSONObject req = new JSONObject(new String(body, encoding));
JSONObject resp = jsonHandler.process(req);
response.setStatus(HttpServletResponse.SC_OK);
response.setContentType("application/json; charset=utf-8");
response.setHeader("Content-Disposition", "attachment;filename=rpc.txt");
return new Result(resp.toString(), true);
} catch (UnsupportedEncodingException e) {
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
logger.log(Level.INFO, e.getMessage(), e);
return new Result("Unsupported input character set", false);
} catch (JSONException e) {
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
return new Result("Malformed JSON request.", false);
} catch (RpcException e) {
response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
logger.log(Level.INFO, e.getMessage(), e);
return new Result(e.getMessage(), false);
}
}
private String getRequestCharacterEncoding(HttpServletRequest request) {
String encoding = request.getCharacterEncoding();
if (encoding == null) {
encoding = "UTF-8";
}
return encoding;
}
private static class Result {
private final String output;
private final boolean success;
public Result(String output, boolean success) {
this.output = output;
this.success = success;
}
public String getOutput() {
return output;
}
public boolean isSuccess() {
return success;
}
}
}