Java 文本类型输入与输出

import java.io.*;
import java.time.LocalDate;
import java.util.Scanner;

public class Test {
    public static void main(String[] args){
//        TextFileTest.test();
//        RandomAccessTest.test();
    }
}

/*
    2.2.3 以文本格式储存对象
 */

class Employee {
    private String name;
    private double salary;
    private LocalDate hireDay;
    public static final int NAME_SIZE = 30;
    public static final int RECORD_SIZE = 50;

    public Employee(String name, double salary, LocalDate hireDay) {
        this.name = name;
        this.salary = salary;
        this.hireDay = hireDay;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getSalary() {
        return salary;
    }

    public void setSalary(double salary) {
        this.salary = salary;
    }

    public LocalDate getHireDay() {
        return hireDay;
    }

    public void setHireDay(LocalDate hireDay) {
        this.hireDay = hireDay;
    }

    @Override
    public String toString() {
        return "Employee{" +
                "name='" + name + '\'' +
                ", salary=" + salary +
                ", hireDay=" + hireDay +
                '}';
    }
}

class TextFileTest {

    public static void test() {
        Employee[] staff = new Employee[]{
                new Employee("A", 10, LocalDate.now()),
                new Employee("B", 20, LocalDate.now()),
                new Employee("C", 30, LocalDate.now())
        };

        try(PrintWriter out = new PrintWriter("employee.dat","UTF-8")) {

            writeData(staff,out);

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }


        try (Scanner in = new Scanner(new FileInputStream("employee.dat"))) {

            Employee[] newStaff = readData(in);

            for (Employee e : newStaff) {
                System.out.println(e);
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }


    }

    private static void writeData(Employee[] employees, PrintWriter out) {
        out.println(employees.length);
        for (Employee e : employees) {
            writeEmployee(out,e);
        }
    }

    private static void writeEmployee(PrintWriter out, Employee employee) {
        out.println(employee.getName()+"|"+employee.getSalary()+"|"+ employee.getHireDay());
    }

    private static Employee[] readData(Scanner in) {
        int n = in.nextInt();
        in.nextLine();

        Employee[] employees = new Employee[n];
        for (int i = 0; i < n; i++) {
            employees[i] = readEmployee(in);
        }
        return employees;
    }

    private static Employee readEmployee(Scanner in) {
        String line = in.nextLine();
        String[] tokens = line.split("\\|");

        String name = tokens[0];
        double salary = Double.parseDouble(tokens[1]);

        //*****************有趣的写法****************
        LocalDate hire = LocalDate.parse(tokens[2]);
        //******************************************

        return new Employee(name, salary, hire);
    }
}

《Java核心技术卷二》笔记