1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 */ 19 20 package org.apache.commons.compress.archivers.zip; 21 22 import java.io.IOException; 23 import java.io.InputStream; 24 import org.apache.commons.compress.utils.BitInputStream; 25 import java.nio.ByteOrder; 26 27 /** 28 * Iterates over the bits of an InputStream. For each byte the bits 29 * are read from the right to the left. 30 * 31 * @since 1.7 32 */ 33 class BitStream extends BitInputStream { 34 BitStream(final InputStream in)35 BitStream(final InputStream in) { 36 super(in, ByteOrder.LITTLE_ENDIAN); 37 } 38 39 /** 40 * Returns the next bit. 41 * 42 * @return The next bit (0 or 1) or -1 if the end of the stream has been reached 43 */ nextBit()44 int nextBit() throws IOException { 45 return (int) readBits(1); 46 } 47 48 /** 49 * Returns the integer value formed by the n next bits (up to 8 bits). 50 * 51 * @param n the number of bits read (up to 8) 52 * @return The value formed by the n bits, or -1 if the end of the stream has been reached 53 */ nextBits(final int n)54 long nextBits(final int n) throws IOException { 55 return readBits(n); 56 } 57 nextByte()58 int nextByte() throws IOException { 59 return (int) readBits(8); 60 } 61 } 62