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