import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.util.ArrayList;
import java.util.Scanner;
/**
* 一个输入器对象Scanner
* 文件
* 集合对象ArrayList
* @author 李章勇
*
*/
public class ShowEmp {
private Scanner sc=new Scanner(System.in);
private File file=new File(FilePath.PATH_NAME);
private ArrayList<Employ> ems;
public ShowEmp() {
if(file.exists()){
try {
ObjectInputStream ois=new ObjectInputStream(new FileInputStream(file));
try {
ems=(ArrayList<Employ>) ois.readObject();
ois.close();
if(ems!=null){
show();
}else{
System.out.println("系统内部问题，无法操作");
return;
}
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}else{
System.out.println("数据文件不存在，无法查看");
return;
}
}
public boolean checkNum(String idStr){
//检测输入格式
if(idStr==null || idStr.equals("")){
System.out.println("非法输入，重来");
return false;
}
char[] cs=idStr.toCharArray();
for(int i=0;i<cs.length;i++){
if(cs[i]<'0' || cs[i]>'9'){
System.out.println("输入非法，重来");
return false;
}
}
return true;
}
private String idStr;
public int getRightNum(){
idStr=sc.nextLine();
if(!checkNum(idStr)){
getRightNum();
}
int id=Integer.parseInt(idStr);
return id;
}
public void show(){
System.out.println("查看全部员工输入Y，查看单个员工输入N");
String choice=sc.nextLine();
if("Y".equalsIgnoreCase(choice)){
System.out.println(ems);
return;
}else if("N".equalsIgnoreCase(choice)){
System.out.println("请输入要查询的员ID：");
int id=getRightNum();
if(SearchID.searchId(id)!=null){
System.out.println("您查找的员工信息为：\n"+SearchID.searchId(id));
return;
}else{
System.out.println("无此用户");
return;
}
}else{
System.out.println("无此命令，请重新选择！");
show();
}
}
}
（3）
package empsystem;