java supercsv_java-如何使用supercsv跳过仅空白行和具有可...

您可以通过编写自己的Tokenizer轻松地做到这一点.

例如,以下Tokenizer的行为与默认行为相同,但是将跳过没有正确列数的任何行.

public class SkipBadColumnCountTokenizer extends Tokenizer {

private final int expectedColumns;

private final List ignoredLines = new ArrayList<>();

public SkipBadColumnCountTokenizer(Reader reader,

CsvPreference preferences, int expectedColumns) {

super(reader, preferences);

this.expectedColumns = expectedColumns;

}

@Override

public boolean readColumns(List columns) throws IOException {

boolean moreInputExists;

while ((moreInputExists = super.readColumns(columns)) &&

columns.size() != this.expectedColumns){

System.out.println(String.format("Ignoring line %s with %d columns: %s", getLineNumber(), columns.size(), getUntokenizedRow()));

ignoredLines.add(getLineNumber());

}

return moreInputExists;

}

public List getIgnoredLines(){

return this.ignoredLines;

}

}

以及使用此Tokenizer进行的简单测试…

@Test

public void testInvalidRows() throws IOException {

String input = "column1,column2,column3

" +

"has,three,columns

" +

"only,two

" +

"one

" +

"three,columns,again

" +

"one,too,many,columns";

CsvPreference preference = CsvPreference.EXCEL_PREFERENCE;

int expectedColumns = 3;

SkipBadColumnCountTokenizer tokenizer = new SkipBadColumnCountTokenizer(

new StringReader(input), preference, expectedColumns);

try (ICsvBeanReader beanReader = new CsvBeanReader(tokenizer, preference)) {

String[] header = beanReader.getHeader(true);

TestBean bean;

while ((bean = beanReader.read(TestBean.class, header)) != null){

System.out.println(bean);

}

System.out.println(String.format("Ignored lines: %s", tokenizer.getIgnoredLines()));

}

}

打印以下输出(注意如何跳过所有无效行)：

TestBean{column1='has', column2='three', column3='columns'}

Ignoring line 3 with 2 columns: only,two

Ignoring line 4 with 1 columns: one

TestBean{column1='three', column2='columns', column3='again'}

Ignoring line 6 with 4 columns: one,too,many,columns

Ignored lines: [3, 4, 6]