Opencsv custom logic in parcing

问题

I'm using openCsv library cause it's very easy to use and I got all necessary functional. But now I need to use some custom logic except checking for correct types, columns and other usual things. I have a csv with columns firstName, secondName, firstSalary, lastSalary and others. I want to check that firstDayOfWork is less than lastDayOfWork in the process of parcing and add a new csvException if it is false. So, if now I'm parcing file

firstName,secondName,firstSalary,lastSalary
John, Doe, testtext, 5000
Alice, , 100, 5000
Harry, Smith, 400, 200

and processing a list of csvExcpetions I can get results of parcing like

Number of mistakes: 2
Line 1: Conversion of testtext to java.lang.Integer failed.
Line 2: Field 'secondName' is mandatory but no value was provided.

I want to something like

Number of mistakes: 3
Line 1: Conversion of testtext to java.lang.Integer failed.
Line 2: Field 'secondName' is mandatory but no value was provided.
Line 3: firstSalary cannot be more than lastSalary

Or some custom parcing logic like check if some field catch regexp, two fields at the same time greater than 0, etc.

I can firstly parce and convert it to beans and by the second cycle check my beans to these rules, but there are can be a lot of lines and it will take longer, so, I want to check it in the one process.

Can I get it by openCsv? And if yes, how? If no, what another tool I can use? Thank you.

回答1:

While there is a request on the todo/wish list for OpenCSV I don't think it will help you because it's about pre parsing validation

For what you want you should just add a check in your setters to throw an exception when the values are bad. Here is my Bean and test.

public class SetterBean {

    @CsvBindByName(column = "First Name", required = true)
    private String firstName;
    @CsvBindByName(column = "Last Name", required = true)
    private String lastName;
    @CsvBindByName(column = "First Salary")
    private Long firstSalary;
    @CsvBindByName(column = "Last Salary")
    private Long lastSalary;

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public void setFirstSalary(Long firstSalary) {
        if (lastSalary != null && (firstSalary.compareTo(lastSalary) > 0)) {
            throw new IllegalArgumentException("First Salary cannot be greater than Last Salary.");
        }
        this.firstSalary = firstSalary;
    }

    public void setLastSalary(Long lastSalary) {
        if (firstSalary != null && (lastSalary.compareTo(firstSalary) < 0)) {
            throw new IllegalArgumentException("Last Salary cannot be less than First Salary.");
        }
        this.lastSalary = lastSalary;
    }
}

public class SetterValidationTest {
    private static final String HEADER = "First Name,Last Name,First Salary,Last Salary\n";

    CsvToBean<SetterBean> csvToBean;

    @Test
    public void normalData() {
        String data = HEADER + "First, Last, 1, 2";
        csvToBean = new CsvToBeanBuilder<SetterBean>(new StringReader(data))
                .withType(SetterBean.class)
                .build();
        List<SetterBean> beans = csvToBean.parse();
        assertEquals(1, beans.size());
    }

    @Test(expected = Exception.class)
    public void firstGTLast() {
        String data = HEADER + "First, Last, 2, 1";
        csvToBean = new CsvToBeanBuilder<SetterBean>(new StringReader(data))
                .withType(SetterBean.class)
                .build();
        List<SetterBean> beans = csvToBean.parse();
    }
}

And here is the result.

Exception in thread "pool-1-thread-1" java.lang.RuntimeException: com.opencsv.exceptions.CsvDataTypeMismatchException
    at com.opencsv.bean.concurrent.ProcessCsvLine.run(ProcessCsvLine.java:91)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)
Caused by: com.opencsv.exceptions.CsvDataTypeMismatchException
    at com.opencsv.bean.AbstractBeanField.assignValueToField(AbstractBeanField.java:192)
    at com.opencsv.bean.AbstractBeanField.setFieldValue(AbstractBeanField.java:159)
    at com.opencsv.bean.concurrent.ProcessCsvLine.processField(ProcessCsvLine.java:140)
    at com.opencsv.bean.concurrent.ProcessCsvLine.processLine(ProcessCsvLine.java:126)
    at com.opencsv.bean.concurrent.ProcessCsvLine.run(ProcessCsvLine.java:82)
    ... 3 more
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at com.opencsv.bean.AbstractBeanField.assignValueToField(AbstractBeanField.java:187)
    ... 7 more
Caused by: java.lang.IllegalArgumentException: Last Salary cannot be less than First Salary.
    at integrationTest.BeanTests.SetterBean.setLastSalary(SetterBean.java:33)
    ... 12 more

Hope that helps.

Scott Conway :)

来源：https://stackoverflow.com/questions/48691164/opencsv-custom-logic-in-parcing

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opencsv