用OpenCSV解析CSV，在带引号的字段中加双引号

Question

我正在尝试使用OpenCSV解析CSV文件。其中一列以YAML序列化格式存储数据，并被引用，因为其中可以包含逗号。它的内部也带有引号，因此可以通过添加两个引号来对其进行转义。我可以在Ruby中轻松解析此文件，但是使用OpenCSV不能完全解析它。这是UTF-8编码的文件。

这是我的Java代码段，正在尝试读取文件

CSVReader reader = new CSVReader(new InputStreamReader(new FileInputStream(csvFilePath), "UTF-8"), ',', '\"', '\\');

这里是此文件的2行。由于我猜测转义的双引号，第一行未正确解析，并且在""[Fair Trade Certified]""处被拆分。

1061658767,update,1196916,Product,28613099,Product::Source,"---
product_attributes:
-
- :name: Ornaments
  :brand_id: 49120
  :size: each
  :alcoholic: false
  :details: ""[Fair Trade Certified]""
  :gluten_free: false
  :kosher: false
  :low_fat: false
  :organic: false
  :sugar_free: false
  :fat_free: false
  :vegan: false
  :vegetarian: false
",,2015-11-01 00:06:19.796944,,,,,,
1061658768,create,,,28613100,Product::Source,"---
product_id:
retailer_id:
store_id:
source_id: 333790
locale: en_us
source_type: Product::PrehistoricProductDatum
priority: 1
is_definition:
product_attributes:
",,2015-11-01 00:06:19.927948,,,,,,

Answer 1

解决方案是使用Paul所建议的与RFC4180兼容的CSV解析器。我曾经使用过OpenCSV的CSVReader，但是它无法正常工作，或者可能无法正常工作。

我使用了FastCSV，这是RFC4180 CSV解析器，它可以无缝运行。

File file = new File(csvFilePath);
CsvReader csvReader = new CsvReader();
CsvContainer csv = csvReader.read(file, StandardCharsets.UTF_8);
for (CsvRow row : csv.getRows()) {
    System.out.println(row.getFieldCount());  
}

Answer 2

首先，我很高兴FastCSV为您工作，但我运行了可疑的子字符串，并通过3.9 openCSV运行了它，它与CsvParser和RFC4180Parser都可以使用。您能否提供一些有关它没有解析的细节，和/或使用3.9 openCSV进行尝试，看看是否遇到相同的问题，然后尝试以下配置。

这是我使用的测试：

CSVParser：

@Test
public void parseBigStringFromStackOverflowWithMultipleQuotesInLine() throws IOException {

    String bigline = "28613099,Product::Source,\"---\n" +
            "product_attributes:\n" +
            "-\n" +
            "- :name: Ornaments\n" +
            "  :brand_id: 49120\n" +
            "  :size: each\n" +
            "  :alcoholic: false\n" +
            "  :details: \"\"[Fair Trade Certified]\"\"\n" +
            "  :gluten_free: false\n" +
            "  :kosher: false\n" +
            "  :low_fat: false\n" +
            "  :organic: false\n" +
            "  :sugar_free: false\n" +
            "  :fat_free: false\n" +
            "  :vegan: false\n" +
            "  :vegetarian: false\n" +
            "\",,2015-11-01 00:06:19.796944";

    String suspectString = "---\n" +
            "product_attributes:\n" +
            "-\n" +
            "- :name: Ornaments\n" +
            "  :brand_id: 49120\n" +
            "  :size: each\n" +
            "  :alcoholic: false\n" +
            "  :details: \"[Fair Trade Certified]\"\n" +
            "  :gluten_free: false\n" +
            "  :kosher: false\n" +
            "  :low_fat: false\n" +
            "  :organic: false\n" +
            "  :sugar_free: false\n" +
            "  :fat_free: false\n" +
            "  :vegan: false\n" +
            "  :vegetarian: false\n" ;

    StringReader stringReader = new StringReader(bigline);

    CSVReaderBuilder builder = new CSVReaderBuilder(stringReader);
    CSVReader csvReader = builder.withFieldAsNull(CSVReaderNullFieldIndicator.BOTH).build();

    String item[] = csvReader.readNext();

    assertEquals(5, item.length);
    assertEquals("28613099", item[0]);
    assertEquals("Product::Source", item[1]);
    assertEquals(suspectString, item[2]);
}

RFC4180Parser

def 'parse big line from stackoverflow with complex string'() {
    given:
    RFC4180ParserBuilder builder = new RFC4180ParserBuilder()
    RFC4180Parser parser = builder.build()
    String bigline = "28613099,Product::Source,\"---\n" +
            "product_attributes:\n" +
            "-\n" +
            "- :name: Ornaments\n" +
            "  :brand_id: 49120\n" +
            "  :size: each\n" +
            "  :alcoholic: false\n" +
            "  :details: \"\"[Fair Trade Certified]\"\"\n" +
            "  :gluten_free: false\n" +
            "  :kosher: false\n" +
            "  :low_fat: false\n" +
            "  :organic: false\n" +
            "  :sugar_free: false\n" +
            "  :fat_free: false\n" +
            "  :vegan: false\n" +
            "  :vegetarian: false\n" +
            "\",,2015-11-01 00:06:19.796944"

    String suspectString = "---\n" +
            "product_attributes:\n" +
            "-\n" +
            "- :name: Ornaments\n" +
            "  :brand_id: 49120\n" +
            "  :size: each\n" +
            "  :alcoholic: false\n" +
            "  :details: \"[Fair Trade Certified]\"\n" +
            "  :gluten_free: false\n" +
            "  :kosher: false\n" +
            "  :low_fat: false\n" +
            "  :organic: false\n" +
            "  :sugar_free: false\n" +
            "  :fat_free: false\n" +
            "  :vegan: false\n" +
            "  :vegetarian: false\n"

    when:
    String[] values = parser.parseLine(bigline)

    then:
    values.length == 5
    values[0] == "28613099"
    values[1] == "Product::Source"
    values[2] == suspectString
}