Java API流文件到ArrayList[重复]

Question

直奔主题。我相信这是很容易解决的，但不知何故我被卡住了。我有一个从主类调用的类上传器。这个类流式传输一个带有学生列表的txt文件并将其打印出来。但是，我找不到一个解决方案，如何将这个txt文件存储在ArrayList中，并在其他类中使用。文件是基于学生类排序的，它覆盖toString方法以获得打印输出。我尝试使用collect（collectors.toList（））方法，但没有奏效。我想我错过了一些明显的东西。有谁能提点什么吗？多谢了。

下面是我为学生类编写的代码：

public class Student extends People {
private String collegeName;
private String studentType;
private final String studentID;

public Student(String firstName, String secondName, String telNo, String collegeName, String studentID, String studentType ) {
    super(firstName, secondName, telNo);
    this.studentID = studentID;
    this.collegeName = collegeName;
    this.studentType = studentType;

}

public String getStudentI() {
    String studentDet = getPeople() + collegeName + " " + studentType + " Student";
    return studentDet;


}
@Override
public String toString() {
    return "Student [name= " + firstName + ", second Name= " + secondName + " Telephone number= " + telNo + "college name= " + collegeName + " Student ID " + studentID + " Student Type= " + studentType + "]";
}

public class Uploader {

private String fileName = null;


private void getPath() {

    JFileChooser chooser = new JFileChooser();
    chooser.showOpenDialog(null);
    File f = chooser.getSelectedFile();
    setFileName(f.getAbsolutePath());
    System.out.println(getFileName());

}
void Uploader() {

    getPath();
    Path path = Paths.get(getFileName());

    try (Stream<String> lines = Files.lines(path)) {
        lines
                .flatMap(Uploader::lineToPerson)
                .forEach(System.out::println);

    } catch (IOException ioe) {

        ioe.printStackTrace();


    }
}


public static Stream<Student> lineToPerson(String line) {

    try {
        String[] elements = line.split(",");
        String firstName = elements[0];
        String secondName = elements[1];
        String telNo = elements[2];
        String collegeName = elements[3];
        String studentID = elements[4];
        String studentType = elements[5];


        Student p = new Student(firstName, secondName, telNo, collegeName, studentID, studentType);

        return Stream.of(p);


    } catch (Exception e) {

    }
    return Stream.empty();
}


public String getFileName() {
    return fileName;
}

public void setFileName(String fileName) {
    this.fileName = fileName;
}

}

Answer 1

这里不需要使用flatMap（）。简单的映射转换可以用来将line转换为Student对象，并将它们收集到一个列表中。

        List<Person> personList = new ArrayList();
        try (Stream<String> lines = Files.lines(path)) {
            personList = lines
                    .map(this::lineToPerson)
                    .collect(Collectors.toList());   
        } catch (IOException ioe) {    
            ioe.printStackTrace();
        }


        public Student lineToPerson(String line) {
            String[] elements = line.split(",");
            String firstName = elements[0];
            String secondName = elements[1];
            String telNo = elements[2];
            String collegeName = elements[3];
            String studentID = elements[4];
            String studentType = elements[5];

            return new Student(firstName, secondName, telNo, collegeName, studentID, studentType);

        }