org.springframework.core.io.buffer.DataBufferInputStream Maven / Gradle / Ivy
/*
* Copyright 2002-2022 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
*
* https://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.springframework.core.io.buffer;
import java.io.IOException;
import java.io.InputStream;
import org.springframework.util.Assert;
/**
* An {@link InputStream} that reads from a {@link DataBuffer}.
*
* @author Arjen Poutsma
* @since 6.0
* @see DataBuffer#asInputStream(boolean)
*/
final class DataBufferInputStream extends InputStream {
private final DataBuffer dataBuffer;
private final int end;
private final boolean releaseOnClose;
private boolean closed;
private int mark;
public DataBufferInputStream(DataBuffer dataBuffer, boolean releaseOnClose) {
Assert.notNull(dataBuffer, "DataBuffer must not be null");
this.dataBuffer = dataBuffer;
int start = this.dataBuffer.readPosition();
this.end = start + this.dataBuffer.readableByteCount();
this.mark = start;
this.releaseOnClose = releaseOnClose;
}
@Override
public int read() throws IOException {
checkClosed();
if (available() == 0) {
return -1;
}
return this.dataBuffer.read() & 0xFF;
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
checkClosed();
int available = available();
if (available == 0) {
return -1;
}
len = Math.min(available, len);
this.dataBuffer.read(b, off, len);
return len;
}
@Override
public boolean markSupported() {
return true;
}
@Override
public void mark(int readLimit) {
Assert.isTrue(readLimit > 0, "readLimit must be greater than 0");
this.mark = this.dataBuffer.readPosition();
}
@Override
public int available() {
return Math.max(0, this.end - this.dataBuffer.readPosition());
}
@Override
public void reset() {
this.dataBuffer.readPosition(this.mark);
}
@Override
public void close() {
if (this.closed) {
return;
}
if (this.releaseOnClose) {
DataBufferUtils.release(this.dataBuffer);
}
this.closed = true;
}
private void checkClosed() throws IOException {
if (this.closed) {
throw new IOException("DataBufferInputStream is closed");
}
}
}