Skip to content
This repository has been archived by the owner. It is now read-only.
Permalink
Browse files
8235792: LineNumberReader.getLineNumber() behavior is inconsistent wi…
…th respect to EOF

Reviewed-by: alanb, darcy, rriggs
  • Loading branch information
Brian Burkhalter committed Aug 5, 2020
1 parent cde65cc commit 6d6fd5faf0b247a3c95225f7dcdf3dae9090e0f2
Show file tree
Hide file tree
Showing 3 changed files with 136 additions and 24 deletions.
@@ -1,5 +1,5 @@
/*
* Copyright (c) 1996, 2019, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1996, 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -302,6 +302,8 @@ public int read(char cbuf[], int off, int len) throws IOException {
* (EOF).
*
* @param ignoreLF If true, the next '\n' will be skipped
* @param term Output: Whether a line terminator was encountered
* while reading the line; may be {@code null}.
*
* @return A String containing the contents of the line, not including
* any line-termination characters, or null if the end of the
@@ -311,13 +313,14 @@ public int read(char cbuf[], int off, int len) throws IOException {
*
* @throws IOException If an I/O error occurs
*/
String readLine(boolean ignoreLF) throws IOException {
String readLine(boolean ignoreLF, boolean[] term) throws IOException {
StringBuilder s = null;
int startChar;

synchronized (lock) {
ensureOpen();
boolean omitLF = ignoreLF || skipLF;
if (term != null) term[0] = false;

bufferLoop:
for (;;) {
@@ -344,6 +347,7 @@ String readLine(boolean ignoreLF) throws IOException {
for (i = nextChar; i < nChars; i++) {
c = cb[i];
if ((c == '\n') || (c == '\r')) {
if (term != null) term[0] = true;
eol = true;
break charLoop;
}
@@ -389,7 +393,7 @@ String readLine(boolean ignoreLF) throws IOException {
* @see java.nio.file.Files#readAllLines
*/
public String readLine() throws IOException {
return readLine(false);
return readLine(false, null);
}

/**
@@ -1,5 +1,5 @@
/*
* Copyright (c) 1996, 2019, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1996, 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -25,30 +25,40 @@

package java.io;


/**
* A buffered character-input stream that keeps track of line numbers. This
* class defines methods {@link #setLineNumber(int)} and {@link
* #getLineNumber()} for setting and getting the current line number
* respectively.
*
* <p> By default, line numbering begins at 0. This number increments at every
* <a href="#lt">line terminator</a> as the data is read, and can be changed
* with a call to {@code setLineNumber(int)}. Note however, that
* {@code setLineNumber(int)} does not actually change the current position in
* the stream; it only changes the value that will be returned by
* <a href="#lt">line terminator</a> as the data is read, and at the end of the
* stream if the last character in the stream is not a line terminator. This
* number can be changed with a call to {@code setLineNumber(int)}. Note
* however, that {@code setLineNumber(int)} does not actually change the current
* position in the stream; it only changes the value that will be returned by
* {@code getLineNumber()}.
*
* <p> A line is considered to be <a id="lt">terminated</a> by any one of a
* line feed ('\n'), a carriage return ('\r'), or a carriage return followed
* immediately by a linefeed.
* immediately by a linefeed, or any of the previous terminators followed by
* end of stream, or end of stream not preceded by another terminator.
*
* @author Mark Reinhold
* @since 1.1
*/

public class LineNumberReader extends BufferedReader {

/** Previous character types */
private static final int NONE = 0; // no previous character
private static final int CHAR = 1; // non-line terminator
private static final int EOL = 2; // line terminator
private static final int EOF = 3; // end-of-file

/** The previous character type */
private int prevChar = NONE;

/** The current line number */
private int lineNumber = 0;

@@ -111,8 +121,10 @@ public int getLineNumber() {

/**
* Read a single character. <a href="#lt">Line terminators</a> are
* compressed into single newline ('\n') characters. Whenever a line
* terminator is read the current line number is incremented.
* compressed into single newline ('\n') characters. The current line
* number is incremented whenever a line terminator is read, or when the
* end of the stream is reached and the last character in the stream is
* not a line terminator.
*
* @return The character read, or -1 if the end of the stream has been
* reached
@@ -134,16 +146,27 @@ public int read() throws IOException {
skipLF = true;
case '\n': /* Fall through */
lineNumber++;
prevChar = EOL;
return '\n';
case -1:
if (prevChar == CHAR)
lineNumber++;
prevChar = EOF;
break;
default:
prevChar = CHAR;
break;
}
return c;
}
}

/**
* Read characters into a portion of an array. Whenever a <a
* href="#lt">line terminator</a> is read the current line number is
* incremented.
* Read characters into a portion of an array.
* <a href="#lt">Line terminators</a> are compressed into single newline
* ('\n') characters. The current line number is incremented whenever a
* line terminator is read, or when the end of the stream is reached and
* the last character in the stream is not a line terminator.
*
* @param cbuf
* Destination buffer
@@ -154,8 +177,8 @@ public int read() throws IOException {
* @param len
* Maximum number of characters to read
*
* @return The number of bytes read, or -1 if the end of the stream has
* already been reached
* @return The number of characters read, or -1 if the end of the stream
* has already been reached
*
* @throws IOException
* If an I/O error occurs
@@ -167,6 +190,13 @@ public int read(char cbuf[], int off, int len) throws IOException {
synchronized (lock) {
int n = super.read(cbuf, off, len);

if (n == -1) {
if (prevChar == CHAR)
lineNumber++;
prevChar = EOF;
return -1;
}

for (int i = off; i < off + n; i++) {
int c = cbuf[i];
if (skipLF) {
@@ -183,13 +213,28 @@ public int read(char cbuf[], int off, int len) throws IOException {
}
}

if (n > 0) {
switch ((int)cbuf[off + n - 1]) {
case '\r':
case '\n': /* Fall through */
prevChar = EOL;
break;
default:
prevChar = CHAR;
break;
}
}

return n;
}
}

/**
* Read a line of text. Whenever a <a href="#lt">line terminator</a> is
* read the current line number is incremented.
* Read a line of text. <a href="#lt">Line terminators</a> are compressed
* into single newline ('\n') characters. The current line number is
* incremented whenever a line terminator is read, or when the end of the
* stream is reached and the last character in the stream is not a line
* terminator.
*
* @return A String containing the contents of the line, not including
* any <a href="#lt">line termination characters</a>, or
@@ -200,10 +245,17 @@ public int read(char cbuf[], int off, int len) throws IOException {
*/
public String readLine() throws IOException {
synchronized (lock) {
String l = super.readLine(skipLF);
boolean[] term = new boolean[1];
String l = super.readLine(skipLF, term);
skipLF = false;
if (l != null)
if (l != null) {
lineNumber++;
prevChar = term[0] ? EOL : EOF;
} else { // l == null
if (prevChar == CHAR)
lineNumber++;
prevChar = EOF;
}
return l;
}
}
@@ -242,6 +294,9 @@ public long skip(long n) throws IOException {
break;
r -= nc;
}
if (n - r > 0) {
prevChar = NONE;
}
return n - r;
}
}
@@ -1,5 +1,5 @@
/*
* Copyright (c) 1998, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1998, 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -22,16 +22,24 @@
*/

/* @test
@bug 4074875 4063511
@bug 4074875 4063511 8235792
@summary Make sure LineNumberReader.read(char, int , int) will increase
the linenumber correctly.
*/

import java.io.*;
import java.io.IOException;
import java.io.LineNumberReader;
import java.io.StringReader;
import java.util.function.Consumer;

public class Read {

public static void main(String[] args) throws Exception {
testReadChars();
testEofs();
}

private static void testReadChars() throws Exception {
String s = "aaaa\nbbb\n";
char[] buf = new char[5];
int n = 0;
@@ -49,4 +57,49 @@ public static void main(String[] args) throws Exception {
throw new Exception("Failed test: Expected line number: 2, got "
+ line);
}

private static void testEofs() throws Exception {
String string = "first \n second";

Consumer<LineNumberReader> c = (LineNumberReader r) -> {
try {
while (r.read() != -1)
continue;
} catch (IOException e) {
throw new RuntimeException(e);
}
};
testEof(c, string, 2);

c = (LineNumberReader r) -> {
try {
char[] buf = new char[128];
while (r.read(buf) != -1)
continue;
} catch (IOException e) {
throw new RuntimeException(e);
}
};
testEof(c, string, 2);

c = (LineNumberReader r) -> {
try {
while (r.readLine() != null)
continue;
} catch (IOException e) {
throw new RuntimeException(e);
}
};
testEof(c, string, 2);
}

private static void testEof(Consumer<LineNumberReader> c, String s, int n)
throws Exception {
LineNumberReader r = new LineNumberReader(new StringReader(s));
c.accept(r);
int line;
if ((line = r.getLineNumber()) != n)
throw new Exception("Failed test: Expected line number: " + n +
" , got " + line);
}
}

0 comments on commit 6d6fd5f

Please sign in to comment.