net.derquinse.common.jaxrs.ByteSourceOutput Maven / Gradle / Ivy
/*
* Copyright (C) the original author or authors.
*
* 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 net.derquinse.common.jaxrs;
import static com.google.common.base.Preconditions.checkNotNull;
import java.io.IOException;
import java.io.OutputStream;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.Response.ResponseBuilder;
import javax.ws.rs.core.StreamingOutput;
import net.derquinse.common.base.NotInstantiable;
import net.derquinse.common.io.MemoryByteSource;
import com.google.common.io.ByteSource;
/**
* Utility methods for building JAX-RS outputs based on {@link ByteSource}s.
* @author Andres Rodriguez.
*/
public final class ByteSourceOutput extends NotInstantiable {
/** Not instantiable. */
private ByteSourceOutput() {
}
private static T checkSource(T source) {
return checkNotNull(source, "The byte source must be provided");
}
/** Creates an {@link StreamingOutput} from the byte source. */
public static StreamingOutput output(final ByteSource source) {
checkSource(source);
return new StreamingOutput() {
@Override
public void write(OutputStream output) throws IOException, WebApplicationException {
source.copyTo(output);
}
};
}
/**
* Adds the Content-Length header to a response if the {@link ByteSource} is a
* {@link MemoryByteSource}.
* @return The provided response builder.
*/
public static ResponseBuilder addLength(ResponseBuilder builder, ByteSource source) {
if (checkSource(source) instanceof MemoryByteSource) {
builder.header(HttpHeaders.CONTENT_LENGTH, Long.toString(((MemoryByteSource)source).size()));
}
return builder;
}
}