org.camunda.bpm.engine.rest.filter.EmptyBodyFilter Maven / Gradle / Ivy
/*
* Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH
* under one or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information regarding copyright
* ownership. Camunda licenses this file to you under the Apache License,
* Version 2.0; 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.camunda.bpm.engine.rest.filter;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PushbackInputStream;
import java.io.InputStream;
import java.nio.charset.Charset;
import java.util.regex.Pattern;
/**
* @author Tassilo Weidner
*/
public class EmptyBodyFilter implements Filter {
protected static final Pattern CONTENT_TYPE_JSON_PATTERN = Pattern.compile("^application\\/json((;)(.*)?)?$", Pattern.CASE_INSENSITIVE);
@Override
public void doFilter(final ServletRequest req, final ServletResponse resp, FilterChain chain) throws IOException, ServletException {
final boolean isContentTypeJson =
CONTENT_TYPE_JSON_PATTERN.matcher(req.getContentType() == null ? "" : req.getContentType()).find();
if (isContentTypeJson) {
final PushbackInputStream requestBody = new PushbackInputStream(req.getInputStream());
int firstByte = requestBody.read();
final boolean isBodyEmpty = firstByte == -1;
requestBody.unread(firstByte);
HttpServletRequestWrapper wrappedRequest = new HttpServletRequestWrapper((HttpServletRequest) req) {
@Override
public ServletInputStream getInputStream() throws IOException {
return new ServletInputStream() {
InputStream inputStream = isBodyEmpty ? new ByteArrayInputStream("{}".getBytes(Charset.forName("UTF-8"))) : requestBody;
@Override
public int read() throws IOException {
return inputStream.read();
}
@Override
public int available() throws IOException {
return inputStream.available();
}
@Override
public void close() throws IOException {
inputStream.close();
}
@Override
public synchronized void mark(int readlimit) {
inputStream.mark(readlimit);
}
@Override
public synchronized void reset() throws IOException {
inputStream.reset();
}
@Override
public boolean markSupported() {
return inputStream.markSupported();
}
};
}
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(this.getInputStream()));
}
};
chain.doFilter(wrappedRequest, resp);
} else {
chain.doFilter(req, resp);
}
}
@Override
public void destroy() {
}
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
}