com.jcabi.http.wire.UserAgentWire Maven / Gradle / Ivy
/**
* Copyright (c) 2011-2014, jcabi.com
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met: 1) Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer. 2) Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution. 3) Neither the name of the jcabi.com nor
* the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.jcabi.http.wire;
import com.jcabi.aspects.Immutable;
import com.jcabi.http.ImmutableHeader;
import com.jcabi.http.Request;
import com.jcabi.http.Response;
import com.jcabi.http.Wire;
import com.jcabi.manifests.Manifests;
import java.io.IOException;
import java.util.Collection;
import java.util.LinkedList;
import java.util.Map;
import javax.validation.constraints.NotNull;
import javax.ws.rs.core.HttpHeaders;
import lombok.EqualsAndHashCode;
import lombok.ToString;
/**
* Wire with default user agent.
*
* This wire adds an extra HTTP header {@code User-Agent} to the request,
* if it's not yet provided, for example:
*
*
String html = new JdkRequest("http://goggle.com")
* .through(UserAgentWire.class)
* .fetch()
* .body();
*
* An actual HTTP request will be sent with {@code User-Agent}
* header with a value {@code ReXSL-0.1/abcdef0 Java/1.6} (for example). It
* is recommended to use this wire decorator when you're working with
* third party RESTful services, to properly identify yourself and avoid
* troubles.
*
*
The class is immutable and thread-safe.
*
* @author Yegor Bugayenko ([email protected])
* @version $Id$
* @since 0.10
* @see RFC 2616 section 14.43 "User-Agent"
*/
@Immutable
@ToString
@EqualsAndHashCode(of = "origin")
public final class UserAgentWire implements Wire {
/**
* Default user agent.
*/
private static final String AGENT = String.format(
"jcabi-%s/%s Java/%s",
Manifests.read("JCabi-Version"),
Manifests.read("JCabi-Build"),
System.getProperty("java.version")
);
/**
* Original wire.
*/
private final transient Wire origin;
/**
* Public ctor.
* @param wire Original wire
*/
public UserAgentWire(@NotNull(message = "wire can't be NULL")
final Wire wire) {
this.origin = wire;
}
/**
* {@inheritDoc}
* @checkstyle ParameterNumber (7 lines)
*/
@Override
public Response send(final Request req, final String home,
final String method,
final Collection> headers,
final byte[] content) throws IOException {
final Collection> hdrs =
new LinkedList>();
boolean absent = true;
for (final Map.Entry header : headers) {
hdrs.add(header);
if (header.getKey().equals(HttpHeaders.USER_AGENT)) {
absent = false;
}
}
if (absent) {
hdrs.add(
new ImmutableHeader(
HttpHeaders.USER_AGENT,
UserAgentWire.AGENT
)
);
}
return this.origin.send(req, home, method, hdrs, content);
}
}