Univocity-将每个TSV文件行解析为不同类型的类对象

Question

我有一个tsv文件，它有固定的行，但每一行都映射到不同的Java类。

例如

recordType  recordValue1
recordType  recordValue1 recordValue2

对于第一排，我有后续类：

public class FirstRow implements ItsvRecord {

    @Parsed(index = 0)
    private String recordType;

    @Parsed(index = 1)
    private String recordValue1;

    public FirstRow() {
    }
}

第二排我有：

public class SecondRow implements ItsvRecord {

    @Parsed(index = 0)
    private String recordType;

    @Parsed(index = 1)
    private String recordValue1;

    public SecondRow() {
    }
}

我想将TSV文件直接解析到相应的对象，但我没有什么想法。

Answer 1

使用InputValueSwitch。这将匹配每行特定列中的值，以确定要使用的Row处理机。示例：

final BeanListProcessor<FirstRow> firstProcessor = new BeanListProcessor<FirstRow>(FirstRow.class);
final BeanListProcessor<SecondRow> secondProcessor = new BeanListProcessor<SecondRow>(SecondRow.class);

//0 means that the first column of each row has a value that 
//identifies what is the type of record you are dealing with
InputValueSwitch valueSwitch = new InputValueSwitch(0);

//assigns the first processor to rows whose first column contain the 'firstRowType' value
valueSwitch.addSwitchForValue("firstRowType", firstProcessor);

//assigns the second processor to rows whose first column contain the 'secondRowType' value
valueSwitch.addSwitchForValue("secondRowType", secondProcessor);

TsvParserSettings settings = new TsvParserSettings(); //configure...
// your row processor is the switch
settings.setProcessor(valueSwitch);

TsvParser parser = new TsvParser(settings);

Reader input = new StringReader(""+
        "firstRowType\trecordValue1\n" +
        "secondRowType\trecordValue1\trecordValue2");

parser.parse(input);

List<FirstRow> firstTypeObjects = firstProcessor.getBeans();
List<SecondRow> secondTypeObjects = secondProcessor.getBeans();

[FirstRow{recordType='firstRowType', recordValue1='recordValue1'}]

[SecondRow{recordType='secondRowType', recordValue1='recordValue1', recordValue2='recordValue2'}]

• 假设在类中实现了一个sane toString（）

如果您的FirstRow应该包含为SecondRow类型的记录解析的元素，只需重写rowProcessorSwitched方法：

    InputValueSwitch valueSwitch = new InputValueSwitch(0) {
    @Override
    public void rowProcessorSwitched(RowProcessor from, RowProcessor to) {
        if (from == secondProcessor) {
            List<FirstRow> firstRows = firstProcessor.getBeans();
            FirstRow mostRecentRow = firstRows.get(firstRows.size() - 1);

            mostRecentRow.addRowsOfOtherType(secondProcessor.getBeans());
            secondProcessor.getBeans().clear();
        }
    }
};

• 以上假设您的FirstRow类有一个addRowsOfOtherType方法，该方法将SecondRow列表作为参数

您甚至可以混合和匹配其他类型的Row处理机。这里有另一个例子可以证明这一点。

希望这有帮助。