axiom-api/src/main/java/org/apache/axiom/mime/PartBlobFactory.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.apache.axiom.mime;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.axiom.ext.io.StreamCopyException;

/**
 * Factory for the {@link PartBlob} instances returned by {@link Part#getBlob()}. This may be used to
 * create {@link PartBlob} instances that wrap some other type of objects representing the content of
 * MIME parts.
 */
public interface PartBlobFactory {
    /**
     * Default factory that creates {@link PartBlob} instances that lazily access the underlying
     * content.
     */
    PartBlobFactory DEFAULT = new PartBlobFactory() {
        @Override
        public PartBlob createBlob(Part part) {
            return new PartBlob() {
                @Override
                public Part getPart() {
                    return part;
                }

                @Override
                public InputStream getInputStream() throws IOException {
                    return part.getBlob().getInputStream();
                }
                
                @Override
                public void writeTo(OutputStream out) throws StreamCopyException {
                    part.getBlob().writeTo(out);
                }
                
                @Override
                public long getSize() {
                    return part.getBlob().getSize();
                }
            };
        }
    };

    /**
     * Create a {@link PartBlob} for the given MIME part.
     * 
     * @param part
     *            the MIME part
     * @return the blob
     */
    PartBlob createBlob(Part part);
}