1 /* 2 * Copyright (C) 2007 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.io; 18 19 import com.google.common.base.Function; 20 import com.google.common.collect.Lists; 21 22 import java.io.BufferedReader; 23 import java.io.FilterReader; 24 import java.io.IOException; 25 import java.io.Reader; 26 import java.io.StringReader; 27 import java.nio.CharBuffer; 28 import java.util.Arrays; 29 import java.util.List; 30 31 /** 32 * Unit tests for {@link LineBuffer} and {@link LineReader}. 33 * 34 * @author Chris Nokleberg 35 */ 36 public class LineBufferTest extends IoTestCase { 37 testProcess()38 public void testProcess() throws IOException { 39 bufferHelper(""); 40 bufferHelper("\n", "\n"); 41 bufferHelper("\r\n", "\r\n"); 42 bufferHelper("\n\r", "\n", "\r"); 43 bufferHelper("\r", "\r"); 44 bufferHelper("\n\n", "\n", "\n"); 45 bufferHelper("\r\n\r\n", "\r\n", "\r\n"); 46 bufferHelper("\r\r", "\r", "\r"); 47 bufferHelper("\ra\r\n\n\r\r", "\r", "a\r\n", "\n", "\r", "\r"); 48 bufferHelper("no newlines at all", "no newlines at all"); 49 bufferHelper("two lines\nbut no newline at end", 50 "two lines\n", "but no newline at end"); 51 bufferHelper("\nempty first line\nno newline at end", 52 "\n", "empty first line\n", "no newline at end"); 53 bufferHelper("three\rlines\rno newline at end", 54 "three\r", "lines\r", "no newline at end"); 55 bufferHelper("mixed\nline\rendings\r\n", 56 "mixed\n", "line\r", "endings\r\n"); 57 } 58 59 private static final int[] CHUNK_SIZES = { 1, 2, 3, Integer.MAX_VALUE }; 60 bufferHelper(String input, String... expect)61 private static void bufferHelper(String input, String... expect) 62 throws IOException { 63 64 List<String> expectProcess = Arrays.asList(expect); 65 List<String> expectRead = Lists.transform(expectProcess, 66 new Function<String, String>() { 67 @Override 68 public String apply(String value) { 69 return value.replaceAll("[\\r\\n]", ""); 70 } 71 }); 72 73 for (int chunk : CHUNK_SIZES) { 74 chunk = Math.max(1, Math.min(chunk, input.length())); 75 assertEquals(expectProcess, bufferHelper(input, chunk)); 76 assertEquals(expectRead, readUsingJava(input, chunk)); 77 assertEquals(expectRead, readUsingReader(input, chunk, true)); 78 assertEquals(expectRead, readUsingReader(input, chunk, false)); 79 } 80 } 81 bufferHelper(String input, int chunk)82 private static List<String> bufferHelper(String input, int chunk) 83 throws IOException { 84 final List<String> lines = Lists.newArrayList(); 85 LineBuffer lineBuf = new LineBuffer() { 86 @Override protected void handleLine(String line, String end) { 87 lines.add(line + end); 88 } 89 }; 90 char[] chars = input.toCharArray(); 91 int off = 0; 92 while (off < chars.length) { 93 int len = Math.min(chars.length, off + chunk) - off; 94 lineBuf.add(chars, off, len); 95 off += len; 96 } 97 lineBuf.finish(); 98 return lines; 99 } 100 readUsingJava(String input, int chunk)101 private static List<String> readUsingJava(String input, int chunk) 102 throws IOException { 103 BufferedReader r = new BufferedReader(getChunkedReader(input, chunk)); 104 List<String> lines = Lists.newArrayList(); 105 String line; 106 while ((line = r.readLine()) != null) { 107 lines.add(line); 108 } 109 r.close(); 110 return lines; 111 } 112 readUsingReader(String input, int chunk, boolean asReader)113 private static List<String> readUsingReader(String input, int chunk, 114 boolean asReader) throws IOException { 115 Readable readable = asReader 116 ? getChunkedReader(input, chunk) 117 : getChunkedReadable(input, chunk); 118 LineReader r = new LineReader(readable); 119 List<String> lines = Lists.newArrayList(); 120 String line; 121 while ((line = r.readLine()) != null) { 122 lines.add(line); 123 } 124 return lines; 125 } 126 127 // Returns a Readable that is *not* a Reader. getChunkedReadable(String input, int chunk)128 private static Readable getChunkedReadable(String input, int chunk) { 129 final Reader reader = getChunkedReader(input, chunk); 130 return new Readable() { 131 @Override 132 public int read(CharBuffer cbuf) throws IOException { 133 return reader.read(cbuf); 134 } 135 }; 136 } 137 138 private static Reader getChunkedReader(String input, final int chunk) { 139 return new FilterReader(new StringReader(input)) { 140 @Override public int read(char[] cbuf, int off, int len) 141 throws IOException { 142 return super.read(cbuf, off, Math.min(chunk, len)); 143 } 144 }; 145 } 146 } 147