/**
* JBoss, Home of Professional Open Source
* Copyright Red Hat, Inc., and individual contributors.
*
* 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 org.jboss.aerogear.unifiedpush.rest.util;
import javax.inject.Inject;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* This filter will change the older api versions to the current one using json diff transform.
*/
@WebFilter(urlPatterns = "*")
public class VersionFilter implements Filter {
private static final String AEROGEAR_VERSION_PREFIX = "aerogear.v";
public static final int VERSION_LENGTH = 3;
@Inject
private RequestTransformer requestTransformer;
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
HttpServletRequest httpRequest = (HttpServletRequest) request;
final String accept = httpRequest.getHeader("accept");
if (accept != null) {
final int index = accept.indexOf(AEROGEAR_VERSION_PREFIX);
if (index != -1) {
final int beginIndex = index + AEROGEAR_VERSION_PREFIX.length();
final String version = accept.substring(beginIndex, beginIndex + VERSION_LENGTH);
chain.doFilter(new TransformHttpServletRequestWrapper(version, httpRequest), response);
return;
}
}
chain.doFilter(request, response);
}
@Override
public void destroy() {
}
private class TransformHttpServletRequestWrapper extends HttpServletRequestWrapper {
private final StringBuilder jsonRequest = new StringBuilder();
private final String path;
private final String version;
TransformHttpServletRequestWrapper(String version, HttpServletRequest httpRequest) throws IOException {
super(httpRequest);
try (BufferedReader reader = httpRequest.getReader()) {
String line;
while ((line = reader.readLine()) != null) {
jsonRequest.append(line);
}
}
String contextPath = httpRequest.getContextPath();
this.path = httpRequest.getRequestURI().substring(contextPath.length());
this.version = version;
}
@Override
public ServletInputStream getInputStream() throws IOException {
StringBuilder data = requestTransformer.transform(path, version, jsonRequest);
final byte[] bytes = data.toString().getBytes();
return new ServletInputStream() {
private InputStream inputStream = new BufferedInputStream(new ByteArrayInputStream(bytes));
@Override
public int read() throws IOException {
return inputStream.read();
}
};
}
}
}