/*
* Copyright 2013 Agorava
*
* 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.agorava.oauth.helpers.extractors;
import org.agorava.api.exception.OAuthParametersMissingException;
import org.agorava.api.extractor.ExtractorType;
import org.agorava.api.extractor.StringExtractor;
import org.agorava.api.oauth.OAuthRequest;
import org.agorava.api.service.OAuthEncoder;
import org.agorava.api.service.Preconditions;
import java.util.Map;
import static org.agorava.api.extractor.ExtractorType.Type.HEADER;
/**
* Extracts HEADER. Conforms to OAuth 1.0a
*
* @author Pablo Fernandez
*/
@ExtractorType(HEADER)
public class HeaderExtractor implements StringExtractor {
private static final String PARAM_SEPARATOR = ", ";
private static final String PREAMBLE = "OAuth ";
/**
* {@inheritDoc}
*/
@Override
public String extract(OAuthRequest request) {
checkPreconditions(request);
Map<String, String> parameters = request.getOauthParameters();
StringBuffer header = new StringBuffer(parameters.size() * 20);
header.append(PREAMBLE);
for (String key : parameters.keySet()) {
if (header.length() > PREAMBLE.length()) {
header.append(PARAM_SEPARATOR);
}
header.append(String.format("%s=\"%s\"", key, OAuthEncoder.encode(parameters.get(key))));
}
return header.toString();
}
private void checkPreconditions(OAuthRequest request) {
Preconditions.checkNotNull(request, "Cannot extract a header from a null object");
if (request.getOauthParameters() == null || request.getOauthParameters().size() <= 0) {
throw new OAuthParametersMissingException(request);
}
}
}