001/*
002 * ====================================================================
003 * Licensed to the Apache Software Foundation (ASF) under one
004 * or more contributor license agreements.  See the NOTICE file
005 * distributed with this work for additional information
006 * regarding copyright ownership.  The ASF licenses this file
007 * to you under the Apache License, Version 2.0 (the
008 * "License"); you may not use this file except in compliance
009 * with the License.  You may obtain a copy of the License at
010 *
011 *   http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing,
014 * software distributed under the License is distributed on an
015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
016 * KIND, either express or implied.  See the License for the
017 * specific language governing permissions and limitations
018 * under the License.
019 * ====================================================================
020 *
021 * This software consists of voluntary contributions made by many
022 * individuals on behalf of the Apache Software Foundation.  For more
023 * information on the Apache Software Foundation, please see
024 * <http://www.apache.org/>.
025 *
026 */
027
028package org.apache.http.entity;
029
030import java.io.ByteArrayInputStream;
031import java.io.ByteArrayOutputStream;
032import java.io.IOException;
033import java.io.InputStream;
034import java.io.OutputStream;
035
036import org.apache.http.util.Args;
037
038/**
039 * Entity that delegates the process of content generation
040 * to a {@link ContentProducer}.
041 *
042 * @since 4.0
043 */
044public class EntityTemplate extends AbstractHttpEntity {
045
046    private final ContentProducer contentproducer;
047
048    public EntityTemplate(final ContentProducer contentproducer) {
049        super();
050        this.contentproducer = Args.notNull(contentproducer, "Content producer");
051    }
052
053    @Override
054    public long getContentLength() {
055        return -1;
056    }
057
058    @Override
059    public InputStream getContent() throws IOException {
060        final ByteArrayOutputStream buf = new ByteArrayOutputStream();
061        writeTo(buf);
062        return new ByteArrayInputStream(buf.toByteArray());
063    }
064
065    @Override
066    public boolean isRepeatable() {
067        return true;
068    }
069
070    @Override
071    public void writeTo(final OutputStream outstream) throws IOException {
072        Args.notNull(outstream, "Output stream");
073        this.contentproducer.writeTo(outstream);
074    }
075
076    @Override
077    public boolean isStreaming() {
078        return false;
079    }
080
081}