com.gitee.starblues.loader.jar.ZipInflaterInputStream Maven / Gradle / Ivy
/*
* Copyright 2012-2021 the original author or authors.
* Copy from spring-boot-loader
*
* 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 com.gitee.starblues.loader.jar;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;
/**
* {@link InflaterInputStream} that supports the writing of an extra "dummy" byte (which
* is required with JDK 6) and returns accurate available() results.
*
* @author Phillip Webb
*/
public class ZipInflaterInputStream extends InflaterInputStream {
private int available;
private boolean extraBytesWritten;
ZipInflaterInputStream(InputStream inputStream, int size) {
super(inputStream, new Inflater(true), getInflaterBufferSize(size));
this.available = size;
}
@Override
public int available() throws IOException {
if (this.available < 0) {
return super.available();
}
return this.available;
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
int result = super.read(b, off, len);
if (result != -1) {
this.available -= result;
}
return result;
}
@Override
public void close() throws IOException {
super.close();
this.inf.end();
}
@Override
protected void fill() throws IOException {
try {
super.fill();
} catch (EOFException ex) {
if (this.extraBytesWritten) {
throw ex;
}
this.len = 1;
this.buf[0] = 0x0;
this.extraBytesWritten = true;
this.inf.setInput(this.buf, 0, this.len);
}
}
private static int getInflaterBufferSize(long size) {
// inflater likes some space
size += 2;
size = (size > 65536) ? 8192 : size;
size = (size <= 0) ? 4096 : size;
return (int) size;
}
}