Try to execute the code example

[Pierre Rougier]

Hello,

Try to execute the code example from the web site get the following error :

java.lang.NoSuchMethodException: general.UserBean.setDate(java.util.Date)
at java.lang.Class.getMethod(Class.java:1605)
at org.supercsv.util.MethodCache.inspectClassForSetMethods(Unknown Source)
at org.supercsv.util.MethodCache.getSetMethod(Unknown Source)
at org.supercsv.io.CsvBeanReader.fillObject(Unknown Source)
at org.supercsv.io.CsvBeanReader.read(Unknown Source)
at general.ReadingObjects.main(ReadingObjects.java:32)
Exception in thread "main" general.UserBean.setDate(java.util.Date)
Can't find method 'setDate(class java.util.Date)' in class 'general.UserBean'. Is the name correctly spelled in the NameMapping? Have you forgot to convert the data so that a wrong set method is called? context: null offending processor: null
at org.supercsv.util.MethodCache.throwException(Unknown Source)
at org.supercsv.util.MethodCache.inspectClassForSetMethods(Unknown Source)
at org.supercsv.util.MethodCache.getSetMethod(Unknown Source)
at org.supercsv.io.CsvBeanReader.fillObject(Unknown Source)
at org.supercsv.io.CsvBeanReader.read(Unknown Source)
at general.ReadingObjects.main(ReadingObjects.java:32)
Caused by: java.lang.NoSuchMethodException: general.UserBean.setDate(java.util.Date)
at java.lang.Class.getMethod(Class.java:1605)
... 5 more

[Kasper B. Graversen]

hi..

this sounds bad. what url is the code example found on?

many thanks

[Dan Barsan]

Getting the same issue here. The problem is that the method we've defined in
the bean class is treated as java.util.Date which is wrong. It should be a
string although we are trying to do a conversion to date type later.

[Dan Barsan]

The URL for this example is locate here:

http://supercsv.sourceforge.net/codeExamples_general.html

[James Bassett]

The UserBean definition at the top is wrong. Use the full example (not quite
'full', as it doesn't import java.util.Date!) code at the end of the code
example which has :

import java.io.FileReader;
import java.io.IOException;

import org.supercsv.cellprocessor.Optional;
import org.supercsv.cellprocessor.ParseDate;
import org.supercsv.cellprocessor.ParseInt;
import org.supercsv.cellprocessor.constraint.StrMinMax;
import org.supercsv.cellprocessor.constraint.Unique;
import org.supercsv.cellprocessor.ift.CellProcessor;
import org.supercsv.io.CsvBeanReader;
import org.supercsv.io.ICsvBeanReader;
import org.supercsv.prefs.CsvPreference;

class ReadingObjects {
    static final CellProcessor[] userProcessors = new CellProcessor[] {
        new Unique(new StrMinMax(5, 20)),
        new StrMinMax(8, 35),
        new ParseDate("dd/MM/yyyy"),
        new Optional(new ParseInt()),
        null
    };

    public static void main(String[] args) throws Exception {
        ICsvBeanReader inFile = new CsvBeanReader(new FileReader("foo.csv"), CsvPreference.EXCEL_PREFERENCE);
        try {
          final String[] header = inFile.getCSVHeader(true);
          UserBean user;
          while( (user = inFile.read(UserBean.class, header, userProcessors)) != null) {
            System.out.println(user.getZip());
          }
        } finally {
          inFile.close();
        }
   }
}

public class UserBean {
    String username, password, town;
    Date date;
    int zip;

    public Date getDate() {
        return date;
    }
    public String getPassword() {
        return password;
    }
    public String getTown() {
        return town;
    }
    public String getUsername() {
        return username;
    }
    public int getZip() {
        return zip;
    }
    public void setDate(final Date date) {
        this.date = date;
    }
    public void setPassword(final String password) {
        this.password = password;
    }

    public void setTown(final String town) {
        this.town = town;
    }
    public void setUsername(final String username) {
        this.username = username;
    }
    public void setZip(final int zip) {
        this.zip = zip;
    }
}

[Anonymous]

I understand on how to assign a Date type to a column in CSV but the problem
remains the same when it comes to conversions. Converting Date to String and
vice-versa.

For instance the following code is giving me an error like this:

Exception in thread "main" java.lang.ClassCastException: java.util.Date cannot
be cast to java.lang.String

at org.supercsv.cellprocessor.ParseDate.execute(Unknown Source)

at org.supercsv.util.Util.processStringList(Unknown Source)

at org.supercsv.io.CsvBeanWriter.write(Unknown Source)

at ca.on.gov.ehealth.scheduler.SynchSchedStatTasks.writeTaskStatus(SynchSchedS
tatTasks.java:81)

at ca.on.gov.ehealth.scheduler.SynchSchedStatTasks.main(SynchSchedStatTasks.ja
va:147)

        String[] header = new String[] {"TaskID","TaskStatus","DateRecorded","TaskResult" };

        // write the partial data
        CsvBeanWriter writer = new CsvBeanWriter(outFile, CsvPreference.EXCEL_PREFERENCE);
        writer.writeHeader(header);
        writer.write(newStatusFile, header, taskStatusProcessors);
        writer.close();

[James Bassett]

Hi,

Just a bit of background information before I answer your question.

Background

CsvBeanReader - converts each column in a row (a String) to a field (Object)
in the bean.

CsvBeanWriter - converts each field (Object) in the bean to a column in a row
(String).

CsvBeanWriter has two write methods:

void write(Object source, String... nameMapping)

void write(Object source, String nameMapping, CellProcessor processor)

The first one does not use any CellProcessors, and simply writes each column
by calling the toString() method of the field in the bean.

The second one uses CellProcessors. If an element in the processor array is
null, then it will behave exactly like the first method and call toString() to
write the column. If you didn't want any special formatting or constraints
applied when writing, then you should use the first method instead. Otherwise
you would use the second method, and for each column that needs formatting or
constraints you can add a chain of CellProcessors. Where toString() is all you
need, you'd just leave that element in the CellProcessor array null.

As the goal of CsvBeanWriter is to convert Objects to Strings, the only
CellProcessors that are really relevant for writing are FmtBool, FmtDate,
FmtNumber and Trim (the ones that take Objects and return a String).

Answer

I'm assuming the dateRecorded field of your newStatusFile object is a Date,
and the definition of your taskStatusProcessors array looks something like
this

CellProcessor[] taskStatusProcessors = new CellProcessor[] {null, null, new ParseDate("dd/MM/yyyy"), null };

The problem with that is that ParseDate is used to take a formatted date
string and return a Date (i.e. it is used for reading, not writing). As it is
encountering a Date instead of a String, you're getting the
ClassCastException.

You can fix your problem by using the FmtDate CellProcessor (which formats a
Date for writing).

CellProcessor[] taskStatusProcessors = new CellProcessor[] {null, null, new FmtDate("dd/MM/yyyy"), null };

Hope this helps,

James

[Anonymous]

Thanks James,

I've fixed the issue by always passing the value to the CSV processor as a
pre-formatted string.

SimpleDateFormat sdfSource = new SimpleDateFormat("dd/MM/yyyy");

It looks like the CSV parser doesn't automatically convert between Date type
formats. I mean it doesn't have the knowledge of interpreting the different
Date Time formats unless you train it to do it. A little bit of polymorphism
could help :)

Cheers,

Dan