ch.vorburger.exec.RollingLogOutputStream Maven / Gradle / Ivy
/*
* #%L
* MariaDB4j
* %%
* Copyright (C) 2012 - 2014 Michael Vorburger
* %%
* 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.
* #L%
*/
package ch.vorburger.exec;
import java.util.Collection;
import org.apache.commons.collections.buffer.CircularFifoBuffer;
import org.apache.commons.exec.LogOutputStream;
/**
* Rolling Process Output Buffer.
*
* @author Michael Vorburger
*/
// intentionally package local for now
class RollingLogOutputStream extends LogOutputStream {
private final Collection ringBuffer;
@SuppressWarnings("unchecked")
RollingLogOutputStream(int maxLines) {
ringBuffer = new CircularFifoBuffer(maxLines);
}
@Override
protected synchronized void processLine(String line, @SuppressWarnings("unused") int level) {
ringBuffer.add(line);
}
/**
* Returns recent lines (up to maxLines from constructor).
*
* The implementation is relatively expensive here; the design is intended for many
* processLine() calls and few getRecentLines().
*
* @return recent Console output
*/
public synchronized String getRecentLines() {
StringBuilder sb = new StringBuilder();
for (String line : ringBuffer) {
if (sb.length() > 0)
sb.append('\n');
sb.append(line);
}
return sb.toString();
}
}