Univocity - 多次读取期间文件头验证问题
Univocity - Issue in file header validation during multiple reads
我正在使用 Univocity-Parser 的 bean 迭代器读取文件的每一行并获取 bean。当我尝试多次读取同一个文件时，我在库中观察到一个奇怪的行为。
将 File 对象传递给 CsvParser 实例时的代码：
private static void testBeanIterator() 抛出异常 {
try {
File sampleFile = generateFile(0);
/*
System.out.println("Sample file content = " + FileUtils.readFileToString(sampleFile,
Charset.defaultCharset()));
*/
for (int i = 0; i < 1000; i++) {
BufferedReader reader =
new BufferedReader(new InputStreamReader(new FileInputStream(sampleFile),
StandardCharsets.UTF_8));
AtomicInteger atomicInteger = new AtomicInteger();
final BeanProcessor<CustomerSegmentMapping> rowProcessor =
new BeanProcessor<CustomerSegmentMapping>(CustomerSegmentMapping.class) {
@Override
public void beanProcessed(@Nonnull final CustomerSegmentMapping customerSegmentMapping,
@Nonnull final ParsingContext context) {
try {
System.out.println(OBJECT_MAPPER.writeValueAsString(customerSegmentMapping));
atomicInteger.getAndAdd(1);
} catch (Exception ex) {
throw new RuntimeException("error");
}
}
};
rowProcessor.setStrictHeaderValidationEnabled(true);
final CsvParserSettings parserSettings = new CsvParserSettings();
parserSettings.setRowProcessor(rowProcessor);
parserSettings.setHeaderExtractionEnabled(true);
final CsvParser parser = new CsvParser(parserSettings);
//parser.parse(reader);
parser.parse(sampleFile);
System.out.println("Finished parser");
if (atomicInteger.get() != 10) {
throw new Exception("mismatch");
}
reader.close();
}
} catch (Exception ex) {
throw new RuntimeException("exception = " + ex.getMessage(), ex);
} finally {
}
}
执行代码时，控制台输出如下：
{"customerId":"6bc12a7a-2c28-4aea-a7be-6be45e16ffb2","segmentId":"S1"}
{"customerId":"da736310-e508-47ff-92b8-59d490e37a72","segmentId":"S1"}
{"customerId":"9a5d4454-e6d4-49a5-bb04-8354154d0493","segmentId":"S1"}
{"customerId":"ec2ed5cc-cd18-443b-bd69-e56fc09ba0f5","segmentId":"S1"}
{"customerId":"94ea24b0-0c83-4039-a391-1d2439c88be8","segmentId":"S1"}
{"customerId":"2baef5f9-d8cd-451d-b579-a626cb58b284","segmentId":"S1"}
{"customerId":"022a184b-1b06-49aa-b1c4-b94a6f343b04","segmentId":"S1"}
{"customerId":"bcb3984c-0495-4da8-b146-9af3983cc158","segmentId":"S1"}
{"customerId":"feef62de-1aaf-43d4-a83b-afe053db97cf","segmentId":"S1"}
{"customerId":"5825c924-55d5-4fd6-8468-ca36d47a7cae","segmentId":"S1"}
Finished parser
{"customerId":"6bc12a7a-2c28-4aea-a7be-6be45e16ffb2","segmentId":"S1"}
{"customerId":"da736310-e508-47ff-92b8-59d490e37a72","segmentId":"S1"}
{"customerId":"9a5d4454-e6d4-49a5-bb04-8354154d0493","segmentId":"S1"}
{"customerId":"ec2ed5cc-cd18-443b-bd69-e56fc09ba0f5","segmentId":"S1"}
{"customerId":"94ea24b0-0c83-4039-a391-1d2439c88be8","segmentId":"S1"}
{"customerId":"2baef5f9-d8cd-451d-b579-a626cb58b284","segmentId":"S1"}
{"customerId":"022a184b-1b06-49aa-b1c4-b94a6f343b04","segmentId":"S1"}
{"customerId":"bcb3984c-0495-4da8-b146-9af3983cc158","segmentId":"S1"}
{"customerId":"feef62de-1aaf-43d4-a83b-afe053db97cf","segmentId":"S1"}
{"customerId":"5825c924-55d5-4fd6-8468-ca36d47a7cae","segmentId":"S1"}
Finished parser
{"customerId":"6bc12a7a-2c28-4aea-a7be-6be45e16ffb2","segmentId":"S1"}
{"customerId":"da736310-e508-47ff-92b8-59d490e37a72","segmentId":"S1"}
{"customerId":"9a5d4454-e6d4-49a5-bb04-8354154d0493","segmentId":"S1"}
{"customerId":"ec2ed5cc-cd18-443b-bd69-e56fc09ba0f5","segmentId":"S1"}
{"customerId":"94ea24b0-0c83-4039-a391-1d2439c88be8","segmentId":"S1"}
{"customerId":"2baef5f9-d8cd-451d-b579-a626cb58b284","segmentId":"S1"}
{"customerId":"022a184b-1b06-49aa-b1c4-b94a6f343b04","segmentId":"S1"}
{"customerId":"bcb3984c-0495-4da8-b146-9af3983cc158","segmentId":"S1"}
{"customerId":"feef62de-1aaf-43d4-a83b-afe053db97cf","segmentId":"S1"}
{"customerId":"5825c924-55d5-4fd6-8468-ca36d47a7cae","segmentId":"S1"}
Finished parser
Exception in thread "main" java.lang.RuntimeException: exception = Could not find fields [CustomerId]' in input. Names found: [ustomerId, SegmentId]
Internal state when error was thrown: line=2, column=0, record=1, charIndex=60, headers=[ustomerId, SegmentId]
at com.poppins.cube.common.UnivocityNahiHatanaHai.testBeanIterator(UnivocityNahiHatanaHai.java:95)
at com.poppins.cube.common.UnivocityNahiHatanaHai.main(UnivocityNahiHatanaHai.java:37)
Caused by: com.univocity.parsers.common.DataProcessingException: Could not find fields [CustomerId]' in input. Names found: [ustomerId, SegmentId]
Internal state when error was thrown: line=2, column=0, record=1, charIndex=60, headers=[ustomerId, SegmentId]
at com.univocity.parsers.common.processor.core.BeanConversionProcessor.mapFieldIndexes(BeanConversionProcessor.java:414)
at com.univocity.parsers.common.processor.core.BeanConversionProcessor.mapValuesToFields(BeanConversionProcessor.java:340)
at com.univocity.parsers.common.processor.core.BeanConversionProcessor.createBean(BeanConversionProcessor.java:508)
at com.univocity.parsers.common.processor.core.AbstractBeanProcessor.rowProcessed(AbstractBeanProcessor.java:54)
at com.univocity.parsers.common.Internal.process(Internal.java:21)
at com.univocity.parsers.common.AbstractParser.rowProcessed(AbstractParser.java:596)
at com.univocity.parsers.common.AbstractParser.parse(AbstractParser.java:133)
at com.univocity.parsers.common.AbstractParser.parse(AbstractParser.java:605)
at com.poppins.cube.common.UnivocityNahiHatanaHai.testBeanIterator(UnivocityNahiHatanaHai.java:83)
... 1 more
Process finished with exit code 1
文件内容如下：
CustomerId,SegmentId
6bc12a7a-2c28-4aea-a7be-6be45e16ffb2,S1
da736310-e508-47ff-92b8-59d490e37a72,S1
9a5d4454-e6d4-49a5-bb04-8354154d0493,S1
ec2ed5cc-cd18-443b-bd69-e56fc09ba0f5,S1
94ea24b0-0c83-4039-a391-1d2439c88be8,S1
2baef5f9-d8cd-451d-b579-a626cb58b284,S1
022a184b-1b06-49aa-b1c4-b94a6f343b04,S1
bcb3984c-0495-4da8-b146-9af3983cc158,S1
feef62de-1aaf-43d4-a83b-afe053db97cf,S1
5825c924-55d5-4fd6-8468-ca36d47a7cae,S1
据我所知，问题的出现是因为我将 File 对象传递给 CsvParser。 CsvParser 在内部创建一个未关闭的 InputStream 对象。
如果我传递的是 Buffered reader 对象而不是 File 对象，则不会出现此问题。
我无法理解这是否是 Univocity-Parsers 的一个已知问题，或者我在理解方面是否遗漏了什么。
这里是图书馆的作者。我可以看到你的异常显示它得到 header ustomerId 而不是 CustomerId.
这看起来像是 2.5.0 版中引入的错误，如果我没记错的话，它已在 2.5.6 版中修复。这困扰了我一段时间，因为这是一个很难追踪的内部并发问题。基本上当你传递一个没有显式编码的文件时，它会尝试在输入中找到一个 UTF BOM 标记（有效地消耗第一个字符）来自动确定编码。这仅发生在 InputStreams 和文件中。
无论如何，这个问题已经修复，所以只需更新到最新版本就可以解决您的问题（如果您使用的不是版本 2，请告诉我。5.something）
如果您想保留现有的当前版本，调用
错误将消失
parser.parse(sampleFile, Charset.defaultCharset());
这将阻止解析器尝试发现您的文件中是否有 BOM 标记，从而避免那个讨厌的错误。
希望对您有所帮助
我正在使用 Univocity-Parser 的 bean 迭代器读取文件的每一行并获取 bean。当我尝试多次读取同一个文件时，我在库中观察到一个奇怪的行为。
将 File 对象传递给 CsvParser 实例时的代码： private static void testBeanIterator() 抛出异常 {
try {
File sampleFile = generateFile(0);
/*
System.out.println("Sample file content = " + FileUtils.readFileToString(sampleFile,
Charset.defaultCharset()));
*/
for (int i = 0; i < 1000; i++) {
BufferedReader reader =
new BufferedReader(new InputStreamReader(new FileInputStream(sampleFile),
StandardCharsets.UTF_8));
AtomicInteger atomicInteger = new AtomicInteger();
final BeanProcessor<CustomerSegmentMapping> rowProcessor =
new BeanProcessor<CustomerSegmentMapping>(CustomerSegmentMapping.class) {
@Override
public void beanProcessed(@Nonnull final CustomerSegmentMapping customerSegmentMapping,
@Nonnull final ParsingContext context) {
try {
System.out.println(OBJECT_MAPPER.writeValueAsString(customerSegmentMapping));
atomicInteger.getAndAdd(1);
} catch (Exception ex) {
throw new RuntimeException("error");
}
}
};
rowProcessor.setStrictHeaderValidationEnabled(true);
final CsvParserSettings parserSettings = new CsvParserSettings();
parserSettings.setRowProcessor(rowProcessor);
parserSettings.setHeaderExtractionEnabled(true);
final CsvParser parser = new CsvParser(parserSettings);
//parser.parse(reader);
parser.parse(sampleFile);
System.out.println("Finished parser");
if (atomicInteger.get() != 10) {
throw new Exception("mismatch");
}
reader.close();
}
} catch (Exception ex) {
throw new RuntimeException("exception = " + ex.getMessage(), ex);
} finally {
}
}
执行代码时，控制台输出如下：
{"customerId":"6bc12a7a-2c28-4aea-a7be-6be45e16ffb2","segmentId":"S1"}
{"customerId":"da736310-e508-47ff-92b8-59d490e37a72","segmentId":"S1"}
{"customerId":"9a5d4454-e6d4-49a5-bb04-8354154d0493","segmentId":"S1"}
{"customerId":"ec2ed5cc-cd18-443b-bd69-e56fc09ba0f5","segmentId":"S1"}
{"customerId":"94ea24b0-0c83-4039-a391-1d2439c88be8","segmentId":"S1"}
{"customerId":"2baef5f9-d8cd-451d-b579-a626cb58b284","segmentId":"S1"}
{"customerId":"022a184b-1b06-49aa-b1c4-b94a6f343b04","segmentId":"S1"}
{"customerId":"bcb3984c-0495-4da8-b146-9af3983cc158","segmentId":"S1"}
{"customerId":"feef62de-1aaf-43d4-a83b-afe053db97cf","segmentId":"S1"}
{"customerId":"5825c924-55d5-4fd6-8468-ca36d47a7cae","segmentId":"S1"}
Finished parser
{"customerId":"6bc12a7a-2c28-4aea-a7be-6be45e16ffb2","segmentId":"S1"}
{"customerId":"da736310-e508-47ff-92b8-59d490e37a72","segmentId":"S1"}
{"customerId":"9a5d4454-e6d4-49a5-bb04-8354154d0493","segmentId":"S1"}
{"customerId":"ec2ed5cc-cd18-443b-bd69-e56fc09ba0f5","segmentId":"S1"}
{"customerId":"94ea24b0-0c83-4039-a391-1d2439c88be8","segmentId":"S1"}
{"customerId":"2baef5f9-d8cd-451d-b579-a626cb58b284","segmentId":"S1"}
{"customerId":"022a184b-1b06-49aa-b1c4-b94a6f343b04","segmentId":"S1"}
{"customerId":"bcb3984c-0495-4da8-b146-9af3983cc158","segmentId":"S1"}
{"customerId":"feef62de-1aaf-43d4-a83b-afe053db97cf","segmentId":"S1"}
{"customerId":"5825c924-55d5-4fd6-8468-ca36d47a7cae","segmentId":"S1"}
Finished parser
{"customerId":"6bc12a7a-2c28-4aea-a7be-6be45e16ffb2","segmentId":"S1"}
{"customerId":"da736310-e508-47ff-92b8-59d490e37a72","segmentId":"S1"}
{"customerId":"9a5d4454-e6d4-49a5-bb04-8354154d0493","segmentId":"S1"}
{"customerId":"ec2ed5cc-cd18-443b-bd69-e56fc09ba0f5","segmentId":"S1"}
{"customerId":"94ea24b0-0c83-4039-a391-1d2439c88be8","segmentId":"S1"}
{"customerId":"2baef5f9-d8cd-451d-b579-a626cb58b284","segmentId":"S1"}
{"customerId":"022a184b-1b06-49aa-b1c4-b94a6f343b04","segmentId":"S1"}
{"customerId":"bcb3984c-0495-4da8-b146-9af3983cc158","segmentId":"S1"}
{"customerId":"feef62de-1aaf-43d4-a83b-afe053db97cf","segmentId":"S1"}
{"customerId":"5825c924-55d5-4fd6-8468-ca36d47a7cae","segmentId":"S1"}
Finished parser
Exception in thread "main" java.lang.RuntimeException: exception = Could not find fields [CustomerId]' in input. Names found: [ustomerId, SegmentId]
Internal state when error was thrown: line=2, column=0, record=1, charIndex=60, headers=[ustomerId, SegmentId]
at com.poppins.cube.common.UnivocityNahiHatanaHai.testBeanIterator(UnivocityNahiHatanaHai.java:95)
at com.poppins.cube.common.UnivocityNahiHatanaHai.main(UnivocityNahiHatanaHai.java:37)
Caused by: com.univocity.parsers.common.DataProcessingException: Could not find fields [CustomerId]' in input. Names found: [ustomerId, SegmentId]
Internal state when error was thrown: line=2, column=0, record=1, charIndex=60, headers=[ustomerId, SegmentId]
at com.univocity.parsers.common.processor.core.BeanConversionProcessor.mapFieldIndexes(BeanConversionProcessor.java:414)
at com.univocity.parsers.common.processor.core.BeanConversionProcessor.mapValuesToFields(BeanConversionProcessor.java:340)
at com.univocity.parsers.common.processor.core.BeanConversionProcessor.createBean(BeanConversionProcessor.java:508)
at com.univocity.parsers.common.processor.core.AbstractBeanProcessor.rowProcessed(AbstractBeanProcessor.java:54)
at com.univocity.parsers.common.Internal.process(Internal.java:21)
at com.univocity.parsers.common.AbstractParser.rowProcessed(AbstractParser.java:596)
at com.univocity.parsers.common.AbstractParser.parse(AbstractParser.java:133)
at com.univocity.parsers.common.AbstractParser.parse(AbstractParser.java:605)
at com.poppins.cube.common.UnivocityNahiHatanaHai.testBeanIterator(UnivocityNahiHatanaHai.java:83)
... 1 more
Process finished with exit code 1
文件内容如下：
CustomerId,SegmentId
6bc12a7a-2c28-4aea-a7be-6be45e16ffb2,S1
da736310-e508-47ff-92b8-59d490e37a72,S1
9a5d4454-e6d4-49a5-bb04-8354154d0493,S1
ec2ed5cc-cd18-443b-bd69-e56fc09ba0f5,S1
94ea24b0-0c83-4039-a391-1d2439c88be8,S1
2baef5f9-d8cd-451d-b579-a626cb58b284,S1
022a184b-1b06-49aa-b1c4-b94a6f343b04,S1
bcb3984c-0495-4da8-b146-9af3983cc158,S1
feef62de-1aaf-43d4-a83b-afe053db97cf,S1
5825c924-55d5-4fd6-8468-ca36d47a7cae,S1
据我所知，问题的出现是因为我将 File 对象传递给 CsvParser。 CsvParser 在内部创建一个未关闭的 InputStream 对象。 如果我传递的是 Buffered reader 对象而不是 File 对象，则不会出现此问题。
我无法理解这是否是 Univocity-Parsers 的一个已知问题，或者我在理解方面是否遗漏了什么。
这里是图书馆的作者。我可以看到你的异常显示它得到 header ustomerId 而不是 CustomerId.
这看起来像是 2.5.0 版中引入的错误，如果我没记错的话，它已在 2.5.6 版中修复。这困扰了我一段时间，因为这是一个很难追踪的内部并发问题。基本上当你传递一个没有显式编码的文件时，它会尝试在输入中找到一个 UTF BOM 标记（有效地消耗第一个字符）来自动确定编码。这仅发生在 InputStreams 和文件中。
无论如何，这个问题已经修复，所以只需更新到最新版本就可以解决您的问题（如果您使用的不是版本 2，请告诉我。5.something）
如果您想保留现有的当前版本，调用
错误将消失parser.parse(sampleFile, Charset.defaultCharset());
这将阻止解析器尝试发现您的文件中是否有 BOM 标记，从而避免那个讨厌的错误。
希望对您有所帮助