org.apache.axiom.util.activation.DataHandlerUtils Maven / Gradle / Ivy
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* 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.util.activation;
import java.io.IOException;
import java.io.OutputStream;
import javax.activation.DataHandler;
import javax.activation.DataSource;
/**
* Contains utility methods to work with {@link DataHandler} objects.
*/
public final class DataHandlerUtils {
private DataHandlerUtils() {}
/**
* Check if the given {@link DataHandler} will produce a byte stream that is longer than a given
* limit. It will first attempt to determine the size using
* {@link DataSourceUtils#getSize(DataSource)}. If that fails, it will use
* {@link DataHandler#writeTo(OutputStream)} to determine if the size is larger than the limit.
*
* @param dh
* the {@link DataHandler} to check
* @param limit
* the limit
* @return {@code true} if the size is larger than {@code limit}, {@code false} otherwise
* @throws IOException
* if {@link DataHandler#writeTo(OutputStream)} produced an unexpected exception
*/
public static boolean isLargerThan(DataHandler dh, long limit) throws IOException {
long size = DataSourceUtils.getSize(dh.getDataSource());
if (size != -1) {
return size > limit;
} else {
// In all other cases, we prefer DataHandler#writeTo over DataSource#getInputStream.
// The reason is that if the DataHandler was constructed from an Object rather than
// a DataSource, a call to DataSource#getInputStream() will start a new thread and
// return a PipedInputStream. This is so for Geronimo's as well as Sun's JAF
// implementation. The reason is that DataContentHandler only has a writeTo and no
// getInputStream method. Obviously starting a new thread just to check the size of
// the data is an overhead that we should avoid.
try {
dh.writeTo(new SizeLimitedOutputStream(limit));
return false;
} catch (SizeLimitExceededException ex) {
return true;
}
}
}
}