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.geronimo.javamail.transport.nntp; 21 22 import java.io.IOException; 23 import java.io.InputStream; 24 import java.io.UnsupportedEncodingException; 25 import java.util.List; 26 27 /** 28 * @version $Rev: 437941 $ $Date: 2006-08-28 23:56:02 -0400 (Mon, 28 Aug 2006) $ 29 */ 30 public class StringListInputStream extends InputStream { 31 // the list of lines we're reading from 32 protected List lines; 33 34 // the next line to process. 35 protected int nextLine = 0; 36 37 // current buffer of bytes to read from 38 byte[] buffer; 39 40 // current offset within the buffer; 41 int offset; 42 43 // indicator that we've left off at a split between the CR and LF of a line 44 // break. 45 boolean atLineBreak = false; 46 47 public StringListInputStream(List lines) throws IOException { 48 this.lines = lines; 49 nextLine = 0; 50 buffer = null; 51 offset = 0; 52 atLineBreak = false; 53 54 // if we have at least one line in the list, get the bytes now. 55 if (lines.size() > 0) { 56 nextBuffer(); 57 } 58 } 59 60 /** 61 * Just override the single byte read version, which handles all of the 62 * lineend markers correctly. 63 * 64 * @return The next byte from the stream or -1 if we've hit the EOF. 65 */ 66 public int read() throws IOException { 67 // leave off at the split between a line? 68 if (atLineBreak) { 69 // flip this off and return the second line end character. Also step 70 // to the next line. 71 atLineBreak = false; 72 nextBuffer(); 73 return '\n'; 74 } 75 // gone past the end? Got an EOF 76 if (buffer == null) { 77 return -1; 78 } 79 80 // reach the end of the line? 81 if (offset >= buffer.length) { 82 // we're now working on a virtual linebreak 83 atLineBreak = true; 84 return '\r'; 85 } 86 // just return the next byte 87 return buffer[offset++]; 88 89 } 90 91 /** 92 * Step to the next buffer of string data. 93 * 94 * @exception IOException 95 */ 96 protected void nextBuffer() throws IOException { 97 // give an eof check. 98 if (nextLine >= lines.size()) { 99 buffer = null; 100 } else { 101 try { 102 String next = (String) lines.get(nextLine++); 103 buffer = next.getBytes("US-ASCII"); 104 105 } catch (UnsupportedEncodingException e) { 106 throw new IOException("Invalid string encoding"); 107 } 108 } 109 110 offset = 0; 111 } 112 }