net.logstash.logback.util.ProxyOutputStream Maven / Gradle / Ivy
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/*
* Copyright 2013-2021 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.logstash.logback.util;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
* A Proxy stream which acts as expected, that is it passes the method calls on
* to the proxied stream and doesn't change which methods are being called (unlike
* JDK {@link FilterOutputStream}).
*
* Note: This class is for internal use only and subject to backward incompatible change
* at any time.
*
* @author brenuart
*/
public class ProxyOutputStream extends OutputStream {
protected OutputStream delegate;
/**
* Constructs a new ProxyOutputStream.
*
* @param delegate the OutputStream to delegate to
*/
public ProxyOutputStream(final OutputStream delegate) {
this.delegate = delegate;
}
/**
* Invokes the delegate's write(int) method.
*
* @param b the byte to write
* @throws IOException if an I/O error occurs
*/
@Override
public void write(final int b) throws IOException {
try {
assertStreamConnected().write(b);
} catch (final IOException e) {
handleIOException(e);
}
}
/**
* Invokes the delegate's write(byte[]) method.
*
* @param b the bytes to write
* @throws IOException if an I/O error occurs
*/
@Override
public void write(final byte[] b) throws IOException {
try {
assertStreamConnected().write(b);
} catch (final IOException e) {
handleIOException(e);
}
}
/**
* Invokes the delegate's write(byte[]) method.
*
* @param b the bytes to write
* @param off The start offset
* @param len The number of bytes to write
* @throws IOException if an I/O error occurs
*/
@Override
public void write(final byte[] b, final int off, final int len) throws IOException {
try {
assertStreamConnected().write(b, off, len);
} catch (final IOException e) {
handleIOException(e);
}
}
/**
* Invokes the delegate's flush() method.
*
* @throws IOException if an I/O error occurs
*/
@Override
public void flush() throws IOException {
try {
assertStreamConnected().flush();
} catch (final IOException e) {
handleIOException(e);
}
}
/**
* Invokes the delegate's close() method.
*
* @throws IOException if an I/O error occurs
*/
@Override
public void close() throws IOException {
try {
assertStreamConnected().close();
} catch (final IOException e) {
handleIOException(e);
}
}
/**
* Handle any IOExceptions thrown.
*
* This method provides a point to implement custom exception handling. The
* default behavior is to re-throw the exception.
*
* @param e The IOException thrown
* @throws IOException if an I/O error occurs
*/
protected void handleIOException(final IOException e) throws IOException {
throw e;
}
/**
* Get the underlying OutputStream and assert it is connected.
*
* @return the underlying OutputStream
* @throws IOException thrown when the stream is not connected
*/
protected OutputStream assertStreamConnected() throws IOException {
if (this.delegate == null) {
throw new IOException("Stream is not connected");
}
return this.delegate;
}
}