员工管理系统（集合与IO流的结合使用 beta5.0 BufferedReader/ BufferedWriter）

package cn.gee;

public class Emp {
    private String id;//员工编号  一般是唯一的
    private String sname;
    private int age;
    private float  salary;
    
    public Emp(){
        
    }
    
    
    public Emp(String id, String sname, int age, float salary) {
        super();
        this.id = id;
        this.sname = sname;
        this.age = age;
        this.salary = salary;
    }

    
    

    @Override
    public String toString() {
        return id+","+sname+","+ age + "," + salary;
    }


    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getSname() {
        return sname;
    }
    public void setSname(String sname) {
        this.sname = sname;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public float getSalary() {
        return salary;
    }
    public void setSalary(float salary) {
        this.salary = salary;
    }
    
    
    
    
}

package cn.gee;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;

/**
 * 1.每个员工信息 一条一条 写到文件中
 * 2.把多个员工（集合）一起写进去或者读出来
 * @author y
 *
 */
public class EmpBussiness {
    List<Emp> emps=new LinkedList<Emp>();
    
    
    public EmpBussiness() throws IOException{
        init();
    }
    private void init() throws IOException{
        read();
    }
    //获得已有的员工信息
    private  void read() throws IOException{
        FileReader fr=new FileReader("C:\zhougb\08\08\08\emps.txt");
        BufferedReader br=new BufferedReader(fr);
        String empStr=null;
        while((empStr=br.readLine())!=null){
            String[] empStrs=empStr.split(",");
            emps.add(new Emp(empStrs[0],empStrs[1],Integer.parseInt(empStrs[2]),Float.parseFloat(empStrs[3])));
        }
        fr.close();
        br.close();
    }
    
    public void write() throws IOException{
        FileWriter fw=new FileWriter("C:\zhougb\08\08\08\emps.txt");
        BufferedWriter bw=new BufferedWriter(fw);
        for(Emp e:emps){
            bw.write(e.toString());
            bw.newLine();
        }
        bw.flush();
        fw.close();
        bw.close();
    }
    
    
    //添加员工
    public void add(Emp emp) throws IOException{
//        read();
        emps.add(emp);
        write();
        
    }
    

    //查询所有员工
    public List<Emp> selectAll() throws IOException{
        //read();
        return emps;
    }
    
    //查询单个员工
    public Emp select(String id){
        
        for(Emp e:emps){
            System.out.println("EmpBussiness.select()"+e.getId());
            if(id.equals(e.getId())){
                return e;
            }
        }
        return  null;
    }
    //删除单个员工
        public boolean  delete(String id) throws IOException{
        
            for(Emp e:emps){
                if(id.equals(e.getId())){
                    emps.remove(e);
                    write();
                    return  true;
                }
            }
        
            return false;
        }
        
        /**修改员工:
         * 1.不论属性有没有值，都覆盖旧的数据
         * 2.如果属性没有值，那么旧的数据就不覆盖
         * @param nemp
         * @return
         */
        public boolean  update(Emp nemp){
            boolean ret=false;
            for(Emp e:emps){
                if(nemp.getId().equals(e.getId())){
                    e.setAge(nemp.getAge());
                    e.setSalary(nemp.getSalary());
                    e.setSname(nemp.getSname());
                    ret= true;
                }
            }
            return ret;
        }
}

package cn.gee;

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

public class View {
    public static void main(String[] args) throws IOException {
        EmpBussiness empBussiness=new EmpBussiness();
        System.out.println("------------------------------员工管理系统beta1.0--------------------------");
        System.out.println("1:添加员工 2:查询员工 3:删除员工 4:修改员工 5:所有员工 6:退出系统");
        Scanner sc=new Scanner(System.in);
        int choice=sc.nextInt();
        while(choice<6){
            switch (choice) {
            case 1:
                System.out.println("请输入名称:");
                String sname=sc.next();
                System.out.println("请输入年龄:");
                int age=sc.nextInt();
                System.out.println("请输入薪资:");
                float salary=sc.nextFloat();
                empBussiness.add(new Emp(Math.round(Math.random()*10000)+"",sname,age,salary));
                System.out.println("添加成功~");
                break;
            case 2:
                System.out.println("请输入编号:");
                String id=sc.next();
                System.out.println("员工编号      员工姓名      员工年龄      员工薪资");
                System.out.println(doShow(empBussiness.select(id)));
                break;
            case 3:
                System.out.println("请输入编号:");
                String did=sc.next();
                empBussiness.delete(did);
                System.out.println("删除成功~");
                break;
            case 4:
                //empBussiness.delete(sc.next());
                break;
            case 5:
                System.out.println("员工编号      员工姓名      员工年龄      员工薪资");
                StringBuilder sb=new StringBuilder();
                List<Emp> emps=empBussiness.selectAll();
                for(Emp e:emps){
                    sb.append(doShow(e));
                }

                System.out.println(sb);
                break;
            case 6:
                return ;

            }
            choice=sc.nextInt();
        }
        
    }
    
    private static  String doShow(Emp e){
        StringBuilder sb=new StringBuilder();
        sb.append(e.getId()+"      ");
        sb.append(e.getSname()+"      ");
        sb.append(e.getAge()+"      ");
        sb.append(e.getSalary()+"      ");
        sb.append("
");
        return sb.toString();
    }
    
    
}