如何保存和加载对象数组列表？

Question

我有一个 class 员工，它具有在数组列表中添加、删除、显示和搜索员工的方法。现在我正在尝试创建一个文件处理程序来保存和读取这些数据，但由于某种原因它不工作并且它没有创建文件或读取它。谁能找到我的代码有问题吗？

Answer 1

我测试了你的代码，但没有发现任何问题。
你为什么不尝试捕获 Throwable 并通过调试来检查它？

try { /* code */ }
catch (Throwable t) { t.printStackTrace(); }

Answer 2

此解决方案测试 EmployeeFileHandler 并在目录不可写等情况下显示错误。运行和 javac EmployeeFileHandler.java; java -ea EmployeeFileHandler 使其在断言失败时崩溃。确保 Person class 也是可序列化的。

import java.util.*;
import java.io.*;

public class EmployeeFileHandler implements Serializable {
    public static void main(String[] args) {
        ArrayList<Employees> employees = new ArrayList<Employees>();
        for (int i = 0; i < 1000; i++) {
            employees.add(new Employees("Name" + i, "Surname" + i, "" + i, 12345678));
        }        
        writeDate(employees);

        ArrayList<Employees> employees2 = new ArrayList<Employees>();
        readData(employees2);

        assert employees.size() == employees2.size();
        for (int i = 0; i < 1000; i++) {
            Employees e = employees2.get(i);
            assert e.Name.equals("Name" + i);
            assert e.Surname.equals("Surname" + i);
            assert e.ID.equals("" + i);
            assert e.MobNo == 12345678;
        }        
    }

    public static void readData(ArrayList<Employees> listIn) {

        boolean endOfFile = false;
        Employees temp;

        try {

            FileInputStream employeesFile = new FileInputStream("employee.obf");
            ObjectInputStream employeesStream = new ObjectInputStream(employeesFile);
            temp = (Employees) employeesStream.readObject();

            while (endOfFile != true) {
                try {
                    listIn.add(temp);
                    temp = (Employees) employeesStream.readObject();
                } catch (EOFException e) {
                    endOfFile = true;
                }
            }
            employeesStream.close();
        }

        catch (FileNotFoundException e) {
            System.out.println("Employee file was not found");
        } catch (IOException e) {
            System.out.println("Employee file could not be read");
        } catch (ClassNotFoundException e) {
            System.out.println("Employee class was not found");
        }
    }

    public static void writeDate(ArrayList<Employees> employee) {

        try {
            FileOutputStream EmployeesFile = new FileOutputStream("employee.obf");
            ObjectOutputStream EmployeesStream = new ObjectOutputStream(EmployeesFile);

            for (Employees employees : employee) {
                EmployeesStream.writeObject(employees);
            }
            EmployeesStream.close();
        } catch (IOException e) {
            // System.out.println("Error occurred while saving");
            e.printStackTrace();
        }
    }
}

如何保存和加载对象数组列表？

How to save and load an array list of objects?

java

load

arraylist

save