员工管理系统（集合与IO流的结合使用 beta3.0 BufferedReader / ObjectOutputStream）

Employee.java

package cn.employee_io;

public class Employee {
    private String empId;
    private String name;
    private int age;
    private double salary;

    public Employee() {
        super();
    }

    public Employee(String empId, String name, int age, double salary) {
        super();
        this.empId = empId;
        this.name = name;
        this.age = age;
        this.salary = salary;
    }

    public String getEmpId() {
        return empId;
    }

    public void setEmpId(String empId) {
        this.empId = empId;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public double getSalary() {
        return salary;
    }

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

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((empId == null) ? 0 : empId.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Employee other = (Employee) obj;
        if (empId == null) {
            if (other.empId != null)
                return false;
        } else if (!empId.equals(other.empId))
            return false;
        return true;
    }

    public String toString() {
        return empId + "," + name + "," + age+ "," + salary;
    }

}
 

Service.java

package cn.employee_io;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.LinkedList;
import java.util.List;

public class Service {
    List<Employee> list = new LinkedList<Employee>();
    File file = null;
    ObjectInputStream ois = null;
    ObjectOutputStream oos = null;

    public Service() throws IOException, ClassNotFoundException {
        reader();
    }

    /**
     * 读文件
     * @throws IOException
     * @throws ClassNotFoundException
     */
    public void reader() throws IOException, ClassNotFoundException {
    /*    file = new File("src/cn/employee_io/emp.txt");
        if (!file.exists()) {
            file.createNewFile();
        }
        ois = new ObjectInputStream(new FileInputStream(file));
        list = (List<Employee>) ois.readObject(); // 给list赋值
        ois.close();*/
        BufferedReader br=new BufferedReader(new FileReader("src/cn/employee_io/emp.txt"));
        String empStr=null;
        while((empStr=br.readLine())!=null){
            String[] empStrs=empStr.split(",");
            list.add(new Employee(empStrs[0],empStrs[1],Integer.parseInt(empStrs[2]),Double.parseDouble(empStrs[3])));
        }
        br.close();
    }

    /**
     * 写文件
     * @throws IOException
     * @throws ClassNotFoundException
     */
    public void writer() throws IOException, ClassNotFoundException {
        file = new File("src/cn/employee_io/emp.txt");
        if (!file.exists()) {
            file.createNewFile();
        }
        oos = new ObjectOutputStream(new FileOutputStream(file));
        for(Employee e:list){
            oos.writeObject(e.toString()+"
"); // 将list值写进文件里去
        }        
        oos.close();
    }

    /**
     * 添加员工
     * @param e
     * @throws ClassNotFoundException
     * @throws IOException
     */
    public void add(Employee e) throws ClassNotFoundException, IOException {
        if (!list.contains(e)) {
            list.add(e);
            writer();
            System.out.println("添加成功！");
        } else {
            System.out.println("添加失败！");
        }
    }
    
    /**
     * 查询所有员工
     */
    public void queryAll(){
        System.out.println("编号          "+"姓名          "+"年龄          "+"薪资");
        for(Employee e:list){
            System.out.println(e.getEmpId()+"  "+e.getName()+"  "+e.getAge()+"  "+e.getSalary());
        }
    }
    
    /**
     * 查询单个员工
     * @param empId
     */
    public void query(String empId){
        for(int i=0;i<list.size();i++){
            if(list.get(i).getEmpId().equals(empId)){
                System.out.println("编号          "+"姓名          "+"年龄          "+"薪资");
                System.out.println(list.get(i).getEmpId()+"  "+list.get(i).getName()+"  "+list.get(i).getAge()+"  "+list.get(i).getSalary());
            }
            if((i==list.size()-1)&&(!list.get(i).getEmpId().equals(empId))){
                System.out.println("不存在该员工！");
            }
        }
    }
    
    /**
     * 删除员工
     * @throws IOException 
     * @throws ClassNotFoundException 
     */
    public void delete(String empId) throws ClassNotFoundException, IOException{
        for(int i=0;i<list.size();i++){
            if(list.get(i).getEmpId().equals(empId)){
                list.remove(list.get(i));    
                writer();
                System.out.println("删除成功！");
                break;
            }
            if((i==list.size()-1)&&(!list.get(i).getEmpId().equals(empId))){
                System.out.println("删除失败！");
            }
        }
    }
    
    /**
     * 修改员工
     * @throws IOException 
     * @throws ClassNotFoundException 
     * 
     */
    public void update(Employee emp) throws ClassNotFoundException, IOException{
        for(int i=0;i<list.size();i++){
            if(list.get(i).getEmpId().equals(emp.getEmpId())){
                list.get(i).setName(emp.getName());
                list.get(i).setAge(emp.getAge());
                list.get(i).setSalary(emp.getSalary());
                writer();
                System.out.println("修改成功！");
            }
            if((i==list.size()-1)&&(!list.get(i).getEmpId().equals(emp.getEmpId()))){
                System.out.println("修改失败！");
            }
        }        
    }
}

TestEmp.java

package cn.employee_io;

import java.io.IOException;
import java.util.Scanner;

public class TestEmp {
    static Scanner sc = new Scanner(System.in);    
    
    static String empId;
    static String name;
    static int age;
    static double salary;
    static int num;

    public static void main(String[] args) throws ClassNotFoundException, IOException {
        Service s=new Service();
        
        ok: for (;;) {
            printOptions();
            num = sc.nextInt(); 

            if (num < 1 || num > 6) {
                System.out.println("输入有误，将重新开始选择！");
                break ok;
            }

            switch (num) {
            case 1:
                printEmpNo();
                printName();
                s.add(new Employee(empId,name,age,salary));
                break;
            case 2:
                s.queryAll();
                break;
            case 3:
                printEmpNo();
                s.query(empId);
                break;
            case 4:
                printEmpNo();
                s.delete(empId);
                break;
            case 5:
                printEmpNo();
                printName();
                s.update(new Employee(empId,name,age,salary));
                break;
            case 6:
                return;
            }
        }
    }

    public static void printOptions() {
        System.out.println("***员工管理系统***");
        System.out.println("1.添加员工");
        System.out.println("2.查询所有员工");
        System.out.println("3.查询员工");
        System.out.println("4.删除员工");
        System.out.println("5.修改员工");
        System.out.println("6.退出");
        System.out.println("请输入你要进行的操作：");
    }

    public static void printEmpNo() {
        System.out.println("请输入员工编号：");
        empId = sc.next();
    }

    public static void printName() {
        System.out.println("请输入员工姓名：");
        name = sc.next();
        System.out.println("请输入员工年龄：");
        age = sc.nextInt();
        System.out.println("请输入员工薪资：");
        salary=sc.nextDouble();
    }
}