Sziasztok!
A következő metódus csv file-ból olvas ki sorokat és objektummá alakítom (minden sor egy objektum):
private static void readData(File inputFile, Class type) {
try {
BufferedReader reader = new BufferedReader(new FileReader(inputFile));
String line;
// Reading first line..
while ((line = reader.readLine()) != null) {
String[] values = line.split(COMMA_DELIMITER);
if (type == Student.class) {
Student student = populateStudent(values);
if (students == null) {
students = new HashMap<Integer, Student>();
}
students.put(student.getStudentId(), student);
}
if (type == Subject.class) {
Mark mark = populateMark(values);
Subject subject = populateSubject(values);
if (subject.getMarks() == null) {
subject.setMarks(new ArrayList<Mark>());
}
students.get(mark.getStudentId()).getSubjects().put(subject.getSubjectId(), subject);
students.get(mark.getStudentId()).getSubjects().get(subject.getSubjectId()).getMarks().add(mark);
}
}
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
}
Ez szeretném megoldani Stream-el:
private static void readData(Path inputFile, Class type) {
Student student;
Subject subject;
Mark mark;
try {
Stream<String> lines = Files.lines(inputFile);
List<List<String>> values = lines.map(line -> Arrays.asList(line.split(COMMA_DELIMITER))).collect(Collectors.toList());
if (type == Student.class) {
values.forEach(value -> student = populateStudent(value));
if (students == null) {
students = new HashMap<Integer, Student>();
}
students.put(student.getStudentId(), student);
}
if (type == Subject.class) {
values.forEach(value -> mark = populateMark(value));
if (subject.getMarks() == null) {
subject.setMarks(new ArrayList<Mark>());
}
students.get(mark.getStudentId()).getSubjects().put(subject.getSubjectId(), subject);
students.get(mark.getStudentId()).getSubjects().get(subject.getSubjectId()).getMarks().add(mark);
}
//}
} catch (Exception e) {
e.printStackTrace();
}
}
A forEach-ben (value -> student = populateStudent(value)
) ezt a hibát kapom: ''Local variable student defined in an enclosing scope must be final or effectively final'
Tudja valaki, hogy lehet ezt megoldani?
Köszi!
[ Szerkesztve ]
A kis emberek más emberekről beszélnek, a középszerű emberek eseményekről, a nagy emberek pedig ötletekről beszélnek.