1 /* 2 * ==================================================================== 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * ==================================================================== 20 * 21 * This software consists of voluntary contributions made by many 22 * individuals on behalf of the Apache Software Foundation. For more 23 * information on the Apache Software Foundation, please see 24 * <http://www.apache.org/>. 25 * 26 */ 27 28 package org.apache.hc.core5.http.impl.io; 29 30 import java.io.IOException; 31 import java.io.InputStream; 32 33 import org.apache.hc.core5.http.StreamClosedException; 34 import org.apache.hc.core5.http.io.SessionInputBuffer; 35 import org.apache.hc.core5.util.Args; 36 37 /** 38 * Input stream that reads data without any transformation. The end of the 39 * content entity is demarcated by closing the underlying connection 40 * (EOF condition). Entities transferred using this input stream can be of 41 * unlimited length. 42 * <p> 43 * Note that this class NEVER closes the underlying stream, even when 44 * {@link #close()} gets called. Instead, the stream will be marked as 45 * closed and no further reading will be permitted. 46 * 47 * @since 4.0 48 */ 49 public class IdentityInputStream extends InputStream { 50 51 private final SessionInputBuffer buffer; 52 private final InputStream inputStream; 53 54 private boolean closed; 55 56 /** 57 * Default constructor. 58 * 59 * @param buffer Session input buffer 60 * @param inputStream Input stream 61 */ 62 public IdentityInputStream(final SessionInputBuffer buffer, final InputStream inputStream) { 63 super(); 64 this.buffer = Args.notNull(buffer, "Session input buffer"); 65 this.inputStream = Args.notNull(inputStream, "Input stream"); 66 } 67 68 @Override 69 public int available() throws IOException { 70 if (this.closed) { 71 return 0; 72 } 73 final int n = this.buffer.length(); 74 return n > 0 ? n : this.inputStream.available(); 75 } 76 77 /** 78 * Marks this stream as closed, but does NOT close the underlying stream. 79 * @throws IOException If an I/O problem occurs. 80 */ 81 @Override 82 public void close() throws IOException { 83 this.closed = true; 84 } 85 86 @Override 87 public int read() throws IOException { 88 if (this.closed) { 89 throw new StreamClosedException(); 90 } 91 return this.buffer.read(this.inputStream); 92 } 93 94 @Override 95 public int read(final byte[] b, final int off, final int len) throws IOException { 96 if (this.closed) { 97 throw new StreamClosedException(); 98 } 99 return this.buffer.read(b, off, len, this.inputStream); 100 } 101 102 }