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[CSV-304] Accessors for header/trailer comments 

Add accessors for header comments (before the header row)
and trailer comments (after the last record)
Also add javadoc and tests
This commit is contained in:
Peter Hull 2022-09-06 14:37:34 +01:00
parent c51b595e34
commit 31a546adab
2 changed files with 177 additions and 2 deletions
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55
src/main/java/org/apache/commons/csv/CSVParser.java
View File

@ -352,6 +352,9 @@ public final class CSVParser implements Iterable<CSVRecord>, Closeable {
return new CSVParser(new InputStreamReader(url.openStream(), charset), format);
}
private String headerComment;
private String trailerComment;
private final CSVFormat format;
@ -480,10 +483,12 @@ public final class CSVParser implements Iterable<CSVRecord>, Closeable {
final CSVRecord nextRecord = this.nextRecord();
if (nextRecord != null) {
headerRecord = nextRecord.values();
headerComment = nextRecord.getComment();
}
} else {
if (this.format.getSkipHeaderRecord()) {
this.nextRecord();
final CSVRecord csvRecord = this.nextRecord();
headerComment = csvRecord.getComment();
}
headerRecord = formatHeader;
}
@ -596,7 +601,49 @@ public final class CSVParser implements Iterable<CSVRecord>, Closeable {
public List<String> getHeaderNames() {
return Collections.unmodifiableList(headers.headerNames);
}
/**
* Checks whether this parser has a header comment, false otherwise.
* The header comment appears before the header record.
* Note that if the parser's format has been given an explicit header
* (with {@link CSVFormat.Builder#setHeader(String... )} or another overload)
* and the header record is not being skipped
* ({@link CSVFormat.Builder#setSkipHeaderRecord} is false) then any initial comments
* will be associated with the first record, not the header.
*
* @return true if this parser has seen a header comment, false otherwise
*/
public boolean hasHeaderComment() {
return headerComment != null;
}
/**
* Returns the header comment for this parser, if any.
* The header comment appears before the header record.
*
* @return the header comment for this stream, or null if no comment is available.
*/
public String getHeaderComment() {
return headerComment;
}
/**
* Checks whether this parser has seen a trailer comment, false otherwise.
* Trailer comments are located between the last record and EOF.
* The trailer comments will only be available after the parser has
* finished processing this stream.
*
* @return true if this parser has seen a trailer comment, false otherwise
*/
public boolean hasTrailerComment() {
return trailerComment != null;
}
/**
* Returns the trailer comment for this record, if any.
* Trailer comments are located between the last record and EOF
*
* @return the trailer comment for this stream, or null if no comment is available.
*/
public String getTrailerComment() {
return trailerComment;
}
/**
* Returns the current record number in the input stream.
*
@ -713,6 +760,10 @@ public final class CSVParser implements Iterable<CSVRecord>, Closeable {
case EOF:
if (this.reusableToken.isReady) {
this.addRecordValue(true);
} else {
if (sb != null) {
trailerComment = sb.toString();
}
}
break;
case INVALID:

124
src/test/java/org/apache/commons/csv/CSVParserTest.java
View File

@ -1375,4 +1375,128 @@ public class CSVParserTest {
parser.close();
}
@Test
public void getHeaderComment() throws IOException {
// File with no header comments
String text_1 = "A,B"+CRLF+"1,2"+CRLF;
// File with a single line header comment
String text_2 = "# comment"+CRLF+"A,B"+CRLF+"1,2"+CRLF;
// File with a multi-line header comment
String text_3 = "# multi-line" + CRLF + "# comment"+CRLF+"A,B"+CRLF+"1,2"+CRLF;
// Format with auto-detected header
CSVFormat format_a = CSVFormat.Builder.create(CSVFormat.DEFAULT).setCommentMarker('#').setHeader().build();
// Format with explicit header
CSVFormat format_b = CSVFormat.Builder.create(CSVFormat.DEFAULT)
.setSkipHeaderRecord(true)
.setCommentMarker('#')
.setHeader("A","B")
.build();
// Format with explicit header that does not skip the header line
CSVFormat format_c = CSVFormat.Builder.create(CSVFormat.DEFAULT)
.setCommentMarker('#')
.setHeader("A","B")
.build();
try (CSVParser parser = CSVParser.parse(text_1, format_a)) {
parser.getRecords();
// Expect no header comment
assertFalse(parser.hasHeaderComment());
assertNull(parser.getHeaderComment());
}
try (CSVParser parser = CSVParser.parse(text_2, format_a)) {
parser.getRecords();
// Expect a header comment
assertTrue(parser.hasHeaderComment());
assertEquals("comment", parser.getHeaderComment());
}
try (CSVParser parser = CSVParser.parse(text_3, format_a)) {
parser.getRecords();
// Expect a header comment
assertTrue(parser.hasHeaderComment());
assertEquals("multi-line"+LF+"comment", parser.getHeaderComment());
}
try (CSVParser parser = CSVParser.parse(text_1, format_b)) {
parser.getRecords();
// Expect no header comment
assertFalse(parser.hasHeaderComment());
assertNull(parser.getHeaderComment());
}
try (CSVParser parser = CSVParser.parse(text_2, format_b)) {
parser.getRecords();
// Expect a header comment
assertTrue(parser.hasHeaderComment());
assertEquals("comment", parser.getHeaderComment());
}
try (CSVParser parser = CSVParser.parse(text_1, format_c)) {
parser.getRecords();
// Expect no header comment
assertFalse(parser.hasHeaderComment());
assertNull(parser.getHeaderComment());
}
try (CSVParser parser = CSVParser.parse(text_2, format_c)) {
parser.getRecords();
// Expect no header comment - the text "comment" is attached to the first record
assertFalse(parser.hasHeaderComment());
assertNull(parser.getHeaderComment());
}
}
@Test
public void getTrailerComment() throws IOException {
// File with a header comment
String text_1 = "# header comment"+CRLF+"A,B"+CRLF+"1,2"+CRLF;
// File with a single line header and trailer comment
String text_2 = "# header comment"+CRLF+"A,B"+CRLF+"1,2"+CRLF + "# comment";
// File with a multi-line header and trailer comment
String text_3 = "# multi-line" + CRLF + "# header comment"+CRLF+"A,B"+CRLF+"1,2"+CRLF+"# multi-line"+CRLF+"# comment";
// Format with auto-detected header
CSVFormat format_a = CSVFormat.Builder.create(CSVFormat.DEFAULT).setCommentMarker('#').setHeader().build();
// Format with explicit header
CSVFormat format_b = CSVFormat.Builder.create(CSVFormat.DEFAULT)
.setSkipHeaderRecord(true)
.setCommentMarker('#')
.setHeader("A","B")
.build();
// Format with explicit header that does not skip the header line
CSVFormat format_c = CSVFormat.Builder.create(CSVFormat.DEFAULT)
.setCommentMarker('#')
.setHeader("A","B")
.build();
try (CSVParser parser = CSVParser.parse(text_1, format_a)) {
parser.getRecords();
assertFalse(parser.hasTrailerComment());
assertNull(parser.getTrailerComment());
}
try (CSVParser parser = CSVParser.parse(text_2, format_a)) {
parser.getRecords();
assertTrue(parser.hasTrailerComment());
assertEquals("comment", parser.getTrailerComment());
}
try (CSVParser parser = CSVParser.parse(text_3, format_a)) {
parser.getRecords();
assertTrue(parser.hasTrailerComment());
assertEquals("multi-line"+LF+"comment", parser.getTrailerComment());
}
try (CSVParser parser = CSVParser.parse(text_1, format_b)) {
parser.getRecords();
assertFalse(parser.hasTrailerComment());
assertNull(parser.getTrailerComment());
}
try (CSVParser parser = CSVParser.parse(text_2, format_b)) {
parser.getRecords();
assertTrue(parser.hasTrailerComment());
assertEquals("comment", parser.getTrailerComment());
}
try (CSVParser parser = CSVParser.parse(text_1, format_c)) {
parser.getRecords();
assertFalse(parser.hasTrailerComment());
assertNull(parser.getTrailerComment());
}
try (CSVParser parser = CSVParser.parse(text_2, format_c)) {
parser.getRecords();
assertTrue(parser.hasTrailerComment());
assertEquals("comment", parser.getTrailerComment());
}
}
}