[CSV-259] CSVFormat.printWithEscapes throws StringIndexOutOfBoundsException when value is Reader

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.8
• Fix Version/s: 1.9.0
• Component/s: Printer

Environment

windows 10

• Assignee: Unassigned
• Reporter: Chen
• Created: 13/Mar/20 07:25
• Updated: 17/Mar/20 14:51
• Resolved: 17/Mar/20 14:51

Description

//代码占位符
@Test
public void testPrintWithEscapeReader() throws IOException {
    final StringWriter sw = new StringWriter();
    final CSVFormat format = CSVFormat.DEFAULT.withEscape('!').withQuoteMode(QuoteMode.NONE);
    Reader reader = new FileReader("src/test/resources/testPrintWithReader.txt");
    try (final CSVPrinter printer = new CSVPrinter(sw, format)) {
        printer.print(reader);
        assertEquals("q!,w!,e", sw.toString());
    }
}

and the values in testPrintWithReader.txt is

//代码占位符
q,w,e

after tracing the code I think the problem cause by here

//代码占位符
private void printWithEscapes(final Reader reader, final Appendable out) throws IOException {
    int start = 0;
    int pos = 0;

    final char delim = getDelimiter();
    final char escape = getEscapeCharacter().charValue();
    final StringBuilder builder = new StringBuilder(IOUtils.DEFAULT_BUFFER_SIZE);

    int c;
    while (-1 != (c = reader.read())) {
        builder.append((char) c);
        if (c == CR || c == LF || c == delim || c == escape) {
            // write out segment up until this char
            if (pos > start) {
                out.append(builder.substring(start, pos));
                builder.setLength(0);
            }
            if (c == LF) {
                c = 'n';
            } else if (c == CR) {
                c = 'r';
            }

            out.append(escape);
            out.append((char) c);

            start = pos + 1; // start on the current char after this one
        }
        pos++;
    }

    // write last segment
    if (pos > start) {
        out.append(builder.substring(start, pos));
    }
}

that line 

//代码占位符
builder.setLength(0);

will cause the exception. After delete that line , the testcase will passed.

is that a bug? may be I could contribute to it

Issue Links

• links to: GitHub Pull Request #61