java核心技术之 ArrayList应用 【职员薪水管理系统】

职员薪水管理系统需求如下：

/**
* author:kevin
* date:20110-7-15
* function:use ArrayList to build a system of EmployeeSalaryMangement ,
* the system is useful for manager to add new employee'information,delete employee'information,
* update employee'information,and show employee'information.
* it's easy to obtain the OOP.
* */
import java.util.ArrayList;
import java.io.*;

public class EmployeeSalary {

public static void main(String[] args) throws Exception{

//create object EmpManage
EmpManage empm = new EmpManage();

InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);
//create a menu
while(true)
{
System.out.println("select what you want to do");
System.out.println("select 1:insert new employee");
System.out.println("select 2:show information");
System.out.println("select 3:delete employee");
System.out.println("select 4:update salary");
System.out.println("select 5:excit");

String oper= br.readLine();
if (oper.equals("1")){
System.out.println("input number:");

String empNo = br.readLine();

System.out.println("input name:");

String empName = br.readLine();

System.out.println("input salary:");

float salary=Float.parseFloat(br.readLine());

Emp emp = new Emp(empNo,empName,salary);

empm.addEmp(emp);

}else if (oper.equals("2")){
System.out.println("input number:");

String empNo = br.readLine();

empm.showEmp(empNo);
}else if (oper.equals("3")){
System.out.println("input number:");

String empNo = br.readLine();

empm.delEmp(empNo);
}else if (oper.equals("4")){
System.out.println("input number:");

String empNo = br.readLine();

System.out.println("input new salary:");

float newSalary =Float.parseFloat(br.readLine()) ;

empm.updateEmp(empNo, newSalary);
}else if (oper.equals("5")){
//exit system.
System.exit(0);
}

}

}

}

//*****************************************************************

//class Employee
class Emp
{
private String empNo; //employee number
private String empName; //employee name
private float salary; //employee salary

public String getEmpNo() {
return empNo;
}
public void setEmpNo(String empNo) {
this.empNo = empNo;
}
public String getEmpName() {
return empName;
}
public void setEmpName(String empName) {
this.empName = empName;
}
public float getSalary() {
return salary;
}
public void setSalary(float salary) {
this.salary = salary;
}

public Emp(String empNo,String empName,float salary)
{
this.empNo = empNo;
this.empName = empName;
this.salary = salary;


}

}

//**********************************************************

//class EmployeeSalaryManage

class EmpManage
{
private ArrayList al = null;

public EmpManage()
{
al = new ArrayList();
}
//insert new employee
public void addEmp(Emp emp)
{
al.add(emp);
}
//show information
public void showEmp(String empNo)
{
for (int i= 0 ;i