fish.payara.micro.boot.loader.jar.Bytes Maven / Gradle / Ivy
/*
* Copyright 2012-2013 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 fish.payara.micro.boot.loader.jar;
import java.io.IOException;
import java.io.InputStream;
import fish.payara.micro.boot.loader.data.RandomAccessData;
import fish.payara.micro.boot.loader.data.RandomAccessData.ResourceAccess;
/**
* Utilities for dealing with bytes from ZIP files.
*
* @author Phillip Webb
*/
final class Bytes {
private static final byte[] EMPTY_BYTES = new byte[] {};
private Bytes() {
}
public static byte[] get(RandomAccessData data) throws IOException {
InputStream inputStream = data.getInputStream(ResourceAccess.ONCE);
try {
return get(inputStream, data.getSize());
}
finally {
inputStream.close();
}
}
public static byte[] get(InputStream inputStream, long length) throws IOException {
if (length == 0) {
return EMPTY_BYTES;
}
byte[] bytes = new byte[(int) length];
if (!fill(inputStream, bytes)) {
throw new IOException("Unable to read bytes");
}
return bytes;
}
public static boolean fill(InputStream inputStream, byte[] bytes) throws IOException {
return fill(inputStream, bytes, 0, bytes.length);
}
private static boolean fill(InputStream inputStream, byte[] bytes, int offset,
int length) throws IOException {
while (length > 0) {
int read = inputStream.read(bytes, offset, length);
if (read == -1) {
return false;
}
offset += read;
length = -read;
}
return true;
}
public static long littleEndianValue(byte[] bytes, int offset, int length) {
long value = 0;
for (int i = length - 1; i >= 0; i--) {
value = ((value << 8) | (bytes[offset + i] & 0xFF));
}
return value;
}
}