Java OpenCSV将具有嵌套bean的对象转换为csv

我试图将一个bean映射到一个包含选定列（不是所有列）的CSV文件，但问题是我的bean有其他嵌套bean作为属性

Class Student {

@CsvBindByName
private String s_id;

@CsvBindByName
private String name;

@CsvRecurse
private List<Book> books;
}

Class Book {

@CsvBindByName
private String bookName;
private String bookAuthor;
}

我尝试了下面的代码，但没有获得csv中的bookName

ColumnPositionMappingStrategy<Student> mapStrategy
                    = new ColumnPositionMappingStrategy<>();

            mapStrategy.setType(Student.class);

            String[] columns = new String[]{"s_id", "name", "bookName"};
            mapStrategy.setColumnMapping(columns);

            StatefulBeanToCsv<Student> btcsv = new StatefulBeanToCsvBuilder<Student>(writer)
                    .withQuotechar(CSVWriter.NO_QUOTE_CHARACTER)
                    .withMappingStrategy(mapStrategy)
                    .withSeparator(';')
                    .build();

            btcsv.write(students);

列位置映射策略映射策略
=新列位置映射策略（）；
mapStrategy.setType（Student.class）；
String[]columns=新字符串[]{“s_id”、“name”、“bookName”}；
setColumnMapping（列）；
StatefulBeanToCsv btcsv=新的StatefulBeanToCsvBuilder（编写器）
.带引号（CSVWriter.无引号字符）
.withMappingStrategy（地图策略）
.带分隔符（“；”）
.build（）；
btcsv.write（学生）；

谁能帮帮我吗

ColumnPositionMappingStrategy<Student> mapStrategy
                    = new ColumnPositionMappingStrategy<>();

            mapStrategy.setType(Student.class);

            String[] columns = new String[]{"s_id", "name", "bookName"};
            mapStrategy.setColumnMapping(columns);

            StatefulBeanToCsv<Student> btcsv = new StatefulBeanToCsvBuilder<Student>(writer)
                    .withQuotechar(CSVWriter.NO_QUOTE_CHARACTER)
                    .withMappingStrategy(mapStrategy)
                    .withSeparator(';')
                    .build();

            btcsv.write(students);