【java对象序列化】

  • 对象序列化

  1. 对象序列化的概念
  1. 将java对象转为二进制的方式，称为对象序列化
  2. 对象序列化以后会加快对象在网络上的传输效率和存储效率。
  3. 序列化的实现方式

1）自定义的实体类实现java.io.Serializable接口即可实现该对象的序列化。

2）对象保存磁盘的操作使用ObjectOutputStream对象进行存储。

ObjectOutputStream的使用方式

ObjectOutputStream os=new ObjectOutputStream(文件字节输出流);

os.writeObject(被序列化的对象);

os.flush();

os.close();

3）未经序列化的类对象，在存储时会出现NoSerializableException异常(未序列化异常)

4)序列化类的实现

package com.bean;

import java.io.Serializable;

public class Student implements Serializable {

    private int sid;

    private String sname;

    private String sex;

    private String address;

    private int age;

    public Student() {

    }

    public Student(int sid, String sname, String sex, String address, int age) {

        this.sid = sid;

        this.sname = sname;

        this.sex = sex;

        this.address = address;

        this.age = age;

    }

    public int getSid() {

        return sid;

    }

    public void setSid(int sid) {

        this.sid = sid;

    }

    public String getSname() {

        return sname;

    }

    public void setSname(String sname) {

        this.sname = sname;

    }

    public String getSex() {

        return sex;

    }

    public void setSex(String sex) {

        this.sex = sex;

    }

    public String getAddress() {

        return address;

    }

    public void setAddress(String address) {

        this.address = address;

    }

    public int getAge() {

        return age;

    }

    public void setAge(int age) {

        this.age = age;

    }

}

存储的示例:

package com.test;

import java.io.*;

import com.bean.*;

public class StudentToFileDemo {

    public static void main(String[] args) {

        File file=new File("stu.bin");

        try {

            FileOutputStream fout=new FileOutputStream(file);

            Student st=new Student(1,"武松","男","景阳冈",22);

            ObjectOutputStream objectOutputStream=new ObjectOutputStream(fout);

            objectOutputStream.writeObject(st);

            objectOutputStream.flush();

            objectOutputStream.close();

            System.out.println("保存成功！");

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

}

  1. 反序列化
  1. 将存储或者在网络上传输的二进制序列化对象转为java类的对象进行使用。这种将序列化的二进制对象转为java类对象的过程称为范序列化。
  2. 使用ObjectInputStream类对象实现反序列化的操作。

ObjectInputStream oin=new ObjectInputStream(文件输入流对象);

Object obj=oin.readObject();

  1. 使用示例

package com.test;

import java.io.*;

import java.lang.reflect.AnnotatedType;

import java.util.ArrayList;

import java.util.LinkedList;

import java.util.List;

import com.bean.*;

public class StudentFromFile {

    public static void main(String[] args) {

        File file=new File("stu.bin");

        try {

            FileInputStream fin=new FileInputStream(file);

            ObjectInputStream oin=new ObjectInputStream(fin);

            Object obj=oin.readObject();

            while (obj!=null){//读取文件中存储的所有对象

                Student st= (Student) obj;

                System.out.println("编号:"+st.getSid());

                System.out.println("姓名:"+st.getSname());

                System.out.println("性别:"+st.getSex());

                System.out.println("地址:"+st.getAddress());

                System.out.println("年龄:"+st.getAge());

                System.out.println("===========================");

                oin=new ObjectInputStream(fin);//从剩余的文件输入流中继续读取数据给对象流

                obj=oin.readObject();

            }

            oin.close();

        } catch (EOFException e){

            System.out.println("文件已到末尾！");

        }catch (IOException e) {

            e.printStackTrace();

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

        }

    }

}

  1. 存储List集合对象到文件(List集合的子类都是经过序列化的，可将此对象进行存储)

package com.test;

import java.io.*;

import com.bean.*;

import java.util.*;

public class ListToFile {

    public static void main(String[] args) {

        File file=new File("studb.bin");

        List<Student> lsst=new ArrayList<>();

        Student st1=new Student(1,"武松","男","景阳冈",22);

        Student st2=new Student(2,"潘金莲","女","景阳冈",21);

        Student st3=new Student(3,"西门庆","男","景阳冈",25);

        Student st4=new Student(4,"林冲","男","汴梁",32);

        Student st5=new Student(5,"鲁智深","男","济南",23);

        Student st6=new Student(6,"阎婆惜","女","郓城",21);

        lsst.add(st1);

        lsst.add(st2);

        lsst.add(st3);

        lsst.add(st4);

        lsst.add(st5);

        lsst.add(st6);

        try {

            FileOutputStream fout=new FileOutputStream(file);

            BufferedOutputStream bout=new BufferedOutputStream(fout);

            ObjectOutputStream objout=new ObjectOutputStream(bout);

            objout.writeObject(lsst);//jdk8.0可以写入

            objout.flush();

            objout.close();

            System.out.println("保存成功！");

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

}

反序列化List集合在程序中呈现

package com.test;

import java.io.*;

import com.bean.*;

import java.util.*;

public class ListFromFile {

    public static void main(String[] args) {

        File file=new File("studb.bin");

        try {

            //创建文件输入流对象

            FileInputStream fin=new FileInputStream(file);

            //创建缓冲区输入流对象

            BufferedInputStream bin=new BufferedInputStream(fin);

            //创建对象输入流

            ObjectInputStream oin=new ObjectInputStream(bin);

            List<Student> lsst= (List<Student>) oin.readObject();

            for (Student st:lsst){

                System.out.println("编号:"+st.getSid());

                System.out.println("姓名:"+st.getSname());

                System.out.println("性别:"+st.getSex());

                System.out.println("地址:"+st.getAddress());

                System.out.println("年龄:"+st.getAge());

                System.out.println("===========================");

            }

        } catch (IOException e) {

            e.printStackTrace();

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

        }

    }

}

  1. 使用序列化和反序列化操作map集合(使用HashMap)
  1. 写出Map集合数据到文件

package com.test;

import java.io.*;

import java.util.*;

import com.bean.*;

public class MapToFile {

    public static void main(String[] args) {

        File file=new File("stumap.bin");

        Student st1=new Student(1,"武松","男","景阳冈",22);

        Student st2=new Student(2,"潘金莲","女","景阳冈",21);

        Student st3=new Student(3,"西门庆","男","景阳冈",25);

        Student st4=new Student(4,"林冲","男","汴梁",32);

        Student st5=new Student(5,"鲁智深","男","济南",23);

        Student st6=new Student(6,"阎婆惜","女","郓城",21);

        Map<Integer,Student> map=new HashMap<>();

        map.put(st1.getSid(),st1);

        map.put(st2.getSid(),st2);

        map.put(st3.getSid(),st3);

        map.put(st4.getSid(),st4);

        map.put(st5.getSid(),st5);

        map.put(st6.getSid(),st6);

        try {

            FileOutputStream fout=new FileOutputStream(file);

            BufferedOutputStream bout=new BufferedOutputStream(fout);

            ObjectOutputStream bs=new ObjectOutputStream(bout);

            bs.writeObject(map);

            bs.flush();

            bs.close();

            System.out.println("map集合写出ok!");

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

}

  1. 从文件中获取Map集合的数据(反序列)

package com.test;

import java.io.*;

import java.util.*;

import com.bean.*;

public class MapToFile {

    public static void main(String[] args) {

        File file=new File("stumap.bin");

        Student st1=new Student(1,"武松","男","景阳冈",22);

        Student st2=new Student(2,"潘金莲","女","景阳冈",21);

        Student st3=new Student(3,"西门庆","男","景阳冈",25);

        Student st4=new Student(4,"林冲","男","汴梁",32);

        Student st5=new Student(5,"鲁智深","男","济南",23);

        Student st6=new Student(6,"阎婆惜","女","郓城",21);

        Map<Integer,Student> map=new HashMap<>();

        map.put(st1.getSid(),st1);

        map.put(st2.getSid(),st2);

        map.put(st3.getSid(),st3);

        map.put(st4.getSid(),st4);

        map.put(st5.getSid(),st5);

        map.put(st6.getSid(),st6);

        try {

            FileOutputStream fout=new FileOutputStream(file);

            BufferedOutputStream bout=new BufferedOutputStream(fout);

            ObjectOutputStream bs=new ObjectOutputStream(bout);

            bs.writeObject(map);

            bs.flush();

            bs.close();

            System.out.println("map集合写出ok!");

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

}

反序列Map集合

package com.test;

import java.io.*;

import java.util.*;

import com.bean.*;

public class MapFromFile {

    public static void main(String[] args) {

        File file=new File("stumap.bin");

        try {

            FileInputStream fin=new FileInputStream(file);

            BufferedInputStream bin=new BufferedInputStream(fin);

            ObjectInputStream oin=new ObjectInputStream(bin);

            Object obj=oin.readObject();

            Map<Integer,Student> map= (Map<Integer, Student>) obj;

            for(Integer key:map.keySet()){//通过Map集合获取键集合Set

                Student st=map.get(key);

                System.out.println("编号:"+st.getSid());

                System.out.println("姓名:"+st.getSname());

                System.out.println("性别:"+st.getSex());

                System.out.println("地址:"+st.getAddress());

                System.out.println("年龄:"+st.getAge());

                System.out.println("===========================");

            };

        } catch (IOException e) {

            e.printStackTrace();

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

        }

    }

}

  1. 使用transient修饰符对成员属性进行非序列化处理

package com.bean;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.Serializable;

import java.util.Date;

public class Student implements Serializable {

    private int sid;

    private String sname;

    private String sex;

    private transient String address;//此属性进行不序列化处理

    private int age;

    public Student() {

    }

    public Student(int sid, String sname, String sex, String address, int age) {

        this.sid = sid;

        this.sname = sname;

        this.sex = sex;

        this.address = address;

        this.age = age;

    }

    public int getSid() {

        return sid;

    }

    public void setSid(int sid) {

        this.sid = sid;

    }

    public String getSname() {

        return sname;

    }

    public void setSname(String sname) {

        this.sname = sname;

    }

    public String getSex() {

        return sex;

    }

    public void setSex(String sex) {

        this.sex = sex;

    }

    public String getAddress() {

        return address;

    }

    public void setAddress(String address) {

        this.address = address;

    }

    public int getAge() {

        return age;

    }

    public void setAge(int age) {

        this.age = age;

    }

    

}

  1. 对非序列化属性进行独立序列化的处理

package com.bean;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.Serializable;

import java.util.Date;

public class Student implements Serializable {

    private int sid;

    private String sname;

    private String sex;

    private transient String address;//此属性进行不序列化处理

    private int age;

    public Student() {

    }

    public Student(int sid, String sname, String sex, String address, int age) {

        this.sid = sid;

        this.sname = sname;

        this.sex = sex;

        this.address = address;

        this.age = age;

    }

    public int getSid() {

        return sid;

    }

    public void setSid(int sid) {

        this.sid = sid;

    }

    public String getSname() {

        return sname;

    }

    public void setSname(String sname) {

        this.sname = sname;

    }

    public String getSex() {

        return sex;

    }

    public void setSex(String sex) {

        this.sex = sex;

    }

    public String getAddress() {

        return address;

    }

    public void setAddress(String address) {

        this.address = address;

    }

    public int getAge() {

        return age;

    }

    public void setAge(int age) {

        this.age = age;

    }

    private void writeObject(ObjectOutputStream objectOutputStream) throws IOException{

            objectOutputStream.defaultWriteObject();

            System.out.println("正在对地址address序列化........");

            address=address+new Date().getTime();

            objectOutputStream.writeUTF(address);

    }

    private void readObject(ObjectInputStream oin) throws IOException, ClassNotFoundException {

        oin.defaultReadObject();

        System.out.println("正在对地址address反序列化........");

        address=oin.readUTF();

    }

}

  1. 使用序列化版本在反序列化时保证对象的一致性

使用序列化版本后，类的属性发生变化，也不会影响到后续对象从文件读取反序列的操作

package com.bean;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.Serializable;

import java.util.Date;

public class Student implements Serializable {

    private static final long serialVersionUID=100000000L;

    private int sid;

    private String sname;

    private String sex;

    private transient String address;//此属性进行不序列化处理

    private int age;

    private int x=10;

    private int y=20;

    public Student() {

    }

    public Student(int sid, String sname, String sex, String address, int age) {

        this.sid = sid;

        this.sname = sname;

        this.sex = sex;

        this.address = address;

        this.age = age;

    }

    public int getSid() {

        return sid;

    }

    public void setSid(int sid) {

        this.sid = sid;

    }

    public String getSname() {

        return sname;

    }

    public void setSname(String sname) {

        this.sname = sname;

    }

    public String getSex() {

        return sex;

    }

    public void setSex(String sex) {

        this.sex = sex;

    }

    public String getAddress() {

        return address;

    }

    public void setAddress(String address) {

        this.address = address;

    }

    public int getAge() {

        return age;

    }

    public int getX() {

        return x;

    }

    public void setX(int x) {

        this.x = x;

    }

    public int getY() {

        return y;

    }

    public void setY(int y) {

        this.y = y;

    }

    public void setAge(int age) {

        this.age = age;

    }

    private void writeObject(ObjectOutputStream objectOutputStream) throws IOException{

            objectOutputStream.defaultWriteObject();

            System.out.println("正在对地址address序列化........");

            address=address+new Date().getTime();

            objectOutputStream.writeUTF(address);

    }

    private void readObject(ObjectInputStream oin) throws IOException, ClassNotFoundException {

        oin.defaultReadObject();

        System.out.println("正在对地址address反序列化........");

        address=oin.readUTF();

    }

}

  • 综合案例
  1. 使用集合框架、流和序列化构建员工信息管理
  2. 构建的步骤
  1. 创建员工实体类并序列化

package com.bean;

import java.io.Serializable;

import java.util.*;

public class Empimplements Serializable{

    private static final long serialVersionUID=1000000002L;

    private int eid;

    private String ename;

    private String sex;

    private String address;

    private String tel;

    private Date birthday;

    private String depname;

    private String hoby;

    public Emp() {

    }

    public Emp(int eid, String ename, String sex, String address, String tel, Date birthday, String depname, String hoby) {

        this.eid = eid;

        this.ename = ename;

        this.sex = sex;

        this.address = address;

        this.tel = tel;

        this.birthday = birthday;

        this.depname = depname;

        this.hoby = hoby;

    }

    public Emp(String ename, String sex, String address, String tel, Date birthday, String depname, String hoby) {

        this.ename = ename;

        this.sex = sex;

        this.address = address;

        this.tel = tel;

        this.birthday = birthday;

        this.depname = depname;

        this.hoby = hoby;

    }

    public int getEid() {

        return eid;

    }

    public void setEid(int eid) {

        this.eid = eid;

    }

    public String getEname() {

        return ename;

    }

    public void setEname(String ename) {

        this.ename = ename;

    }

    public String getSex() {

        return sex;

    }

    public void setSex(String sex) {

        this.sex = sex;

    }

    public String getAddress() {

        return address;

    }

    public void setAddress(String address) {

        this.address = address;

    }

    public String getTel() {

        return tel;

    }

    public void setTel(String tel) {

        this.tel = tel;

    }

    public Date getBirthday() {

        return birthday;

    }

    public void setBirthday(Date birthday) {

        this.birthday = birthday;

    }

    public String getDepname() {

        return depname;

    }

    public void setDepname(String depname) {

        this.depname = depname;

    }

    public String getHoby() {

        return hoby;

    }

    public void setHoby(String hoby) {

        this.hoby = hoby;

    }

}

  1. 构建工具类，向文件中写入员工集合对象，从文件中获取员工的集合信息

EmpUtil.java

package com.util;

import java.io.*;

import java.util.*;

import com.bean.*;

public class EmpUtil {

    private File file=null;

    public EmpUtil(){

        file= new File("empdb.bin");

    }

    /**

     * 向文件中写入员工的集合

     * */

    public void writeListToFile(List<Emp> lsemp){

        //File file=new File("empdb.bin");

        try {

            FileOutputStream fout=new FileOutputStream(file);

            BufferedOutputStream bout=new BufferedOutputStream(fout);

            ObjectOutputStream os=new ObjectOutputStream(bout);

            if(lsemp!=null&&lsemp.size()>0){

                  os.writeObject(lsemp);

            }

            os.flush();

            os.close();

            System.out.println("员工集合信息写出到文件成功！");

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

    /*****

     * 从文件获取员工集合信息

     * */

    public List<Emp> readListFromFile(){

        if(!file.exists()){

            return null;

        }

        try {

            FileInputStream fin=new FileInputStream(file);

            BufferedInputStream bin=new BufferedInputStream(fin);

            ObjectInputStream oin=new ObjectInputStream(bin);

            List<Emp> lsemp= (List<Emp>) oin.readObject();

            return lsemp;

        } catch (IOException e) {

            e.printStackTrace();

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

        }

        return null;

    }

}

  1. 构建业务接口和实现类

EmpBiz.java

package com.biz;

public interface EmpBiz<Emp> {

    public void save(Emp emp);

    public void update(Emp emp);

    public void delById(int eid);

    public void findById(int eid);

    public void findAll();

    /**

     * 判断是否存在相同的编号，修改数据时使用

     * */

    public boolean isSid(int eid);

}

EmpBizImp.java

package com.biz;

import java.text.SimpleDateFormat;

import java.util.*;

import com.bean.*;

import java.io.*;

import com.util.*;

public class EmpBizImp implements EmpBiz<Emp> {

    private List<Emp> lsemp=null;

    private int eid;//员工编号

    private EmpUtil empUtil=new EmpUtil();//创建自己的工具类对象准备读写文件

    @Override

    public void save(Emp emp) {

        //从文件中获取员工的集合

        lsemp=empUtil.readListFromFile();

        /******************处理员工编号的自增***********/

        if(lsemp==null||lsemp.isEmpty()){

            lsemp=new ArrayList<>();

            eid=1;

            emp.setEid(eid);

        }else{

            List<Integer> lseid=new ArrayList<>();//用于存储员工的编号信息

            for(Emp emp1:lsemp){

                lseid.add(emp1.getEid());

            }

            int maxeid=Collections.max(lseid);

            maxeid++;//保证编号不重复

            emp.setEid(maxeid);

        }

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

        boolean flag=lsemp.add(emp);

        if(flag){

            empUtil.writeListToFile(lsemp);//写集合到文件中存储

            System.out.println("保存成功！");

        }else{

            System.out.println("保存失败！");

        }

    }

    @Override

    public void update(Emp emp) {

        //从文件中获取员工的集合

        lsemp=empUtil.readListFromFile();

        if(lsemp==null||lsemp.isEmpty()){

            System.out.println("没有员工信息存在，请先添加！");

            return;

        }

        int index=-1;

        int i=0;

        /***********找编号************************/

        for(Emp emp1:lsemp){

            if(emp1.getEid()==emp.getEid()){//判断集合中是否存在员工

                index=i;

                break;

            }

            i++;

        }

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

        if(index!=-1){

            lsemp.set(index,emp);//更新

            empUtil.writeListToFile(lsemp);//保存更新后的集合对象到文件

            System.out.println("更新成功！");

        }else{

            System.out.println("查无此人，更新失败！");

        }

    }

    @Override

    public void delById(int eid) {

        //从文件中获取员工的集合

        lsemp=empUtil.readListFromFile();

        if(lsemp==null||lsemp.isEmpty()){

            System.out.println("没有员工信息存在，请先添加！");

            return;

        }

        int index=-1;

        int i=0;

        /***********找编号************************/

        for(Emp emp1:lsemp){

            if(emp1.getEid()==eid){//判断集合中是否存在员工

                index=i;

                break;

            }

            i++;

        }

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

        if(index!=-1){

            lsemp.remove(index);//删除索引位置处的员工对象

            empUtil.writeListToFile(lsemp);//存储更新后的集合对象到文件

            System.out.println("更新成功！");

        }else{

            System.out.println("查无此人，更新失败！");

        }

    }

    @Override

    public void findById(int eid) {

        //从文件中获取员工的集合

        lsemp=empUtil.readListFromFile();

        if(lsemp==null||lsemp.isEmpty()){

            System.out.println("没有员工信息存在，请先添加！");

            return;

        }

        int index=-1;

        int i=0;

        /***********找编号************************/

        for(Emp emp1:lsemp){

            if(emp1.getEid()==eid){//判断集合中是否存在员工

                index=i;

                break;

            }

            i++;

        }

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

        if(index!=-1){

            System.out.println("编号\t姓名\t性别\t地址\t电话\t生日\t部门\t爱好");

            System.out.println("================================================");

            Emp emp=lsemp.get(index);

            showEmp(emp);

            System.out.println("================================================");

        }else{

            System.out.println("查无此人！");

        }

    }

    @Override

    public void findAll() {

        //从文件中获取员工的集合

        lsemp=empUtil.readListFromFile();

        if(lsemp==null||lsemp.isEmpty()){

            System.out.println("没有员工信息存在，请先添加！");

            return;

        }

        System.out.println("编号\t姓名\t性别\t地址\t电话\t生日\t部门\t爱好");

        System.out.println("================================================");

        for(Emp emp:lsemp){

            showEmp(emp);

        }

        System.out.println("================================================");

    }

    @Override

    public boolean isSid(int eid) {

        //从文件中获取员工的集合

        lsemp=empUtil.readListFromFile();

        if(lsemp==null||lsemp.isEmpty()){

            System.out.println("没有员工信息存在，请先添加！");

            return false;

        }

        /***********找编号************************/

        for(Emp emp1:lsemp){

            if(emp1.getEid()==eid){//判断集合中是否存在员工

                return true;

            }

        }

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

        return false;

    }

    public void showEmp(Emp emp){

        System.out.println(

                emp.getEid()+"\t"+

                emp.getEname()+"\t"+

                emp.getSex()+"\t"+

                emp.getAddress()+"\t"+

                emp.getTel()+"\t"+

                new SimpleDateFormat("yyyy-MM-dd").format(emp.getBirthday())+"\t"+

                emp.getDepname()+"\t"+

                emp.getHoby()

        );

    }

}

  1. 构建界面交互

EmpAction.java

package com.action;

import com.biz.*;

import com.bean.*;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.*;

public class EmpAction {

    private EmpBiz ebiz=new EmpBizImp();

    private Scanner input=new Scanner(System.in);

    /**

     * 录入员工信息的方法

     * */

    public Emp inputEmpInfo(){

        Emp emp=new Emp();

        System.out.println("输入姓名:");

        emp.setEname(input.next());

        System.out.println("输入性别:");

        emp.setSex(input.next());

        System.out.println("输入地址:");

        emp.setAddress(input.next());

        System.out.println("输入电话:");

        emp.setTel(input.next());

        while(true){

            try {

                System.out.println("输入生日（1990-01-01）:");

                String sdate=input.next();

                Date bdate=new SimpleDateFormat("yyyy-MM-dd").parse(sdate);

                emp.setBirthday(bdate);

                break;

            } catch (ParseException e) {

                System.out.println("日期格式错误！");

                input=null;

                input=new Scanner(System.in);

            }

        }

        System.out.println("输入部门:");

        emp.setDepname(input.next());

        System.out.println("输入爱好:");

        emp.setHoby(input.next());

        return emp;

    }

    /**

     * 菜单

     * */

    public void showMenu(){

        int eid=-1;

        while (true){

            try {

                System.out.println("==员工信息管理==");

                System.out.println("1--添加");

                System.out.println("2--修改");

                System.out.println("3--删除");

                System.out.println("4--查找");

                System.out.println("5--显示");

                System.out.println("0--退出");

                System.out.println("==============");

                System.out.println("请输入选择(0-5)之间的数字:");

                int op=input.nextInt();

                switch (op){

                    case 1:

                        System.out.println("员工信息>>添加>>");

                        Emp emp=inputEmpInfo();

                        ebiz.save(emp);//保存

                        break;

                    case 2:

                        System.out.println("员工信息>>修改>>");

                        System.out.println("输入员工编号:");

                        eid=input.nextInt();

                        boolean flag=ebiz.isSid(eid);

                        if(!flag){

                            System.out.println("没有此编号的员工存在，请重新选择！");

                            break;

                        }

                        emp=inputEmpInfo();

                        emp.setEid(eid);

                        ebiz.update(emp);//更新

                        break;

                    case 3:

                        System.out.println("员工信息>>删除>>");

                        System.out.println("输入员工编号:");

                        eid=input.nextInt();

                        flag=ebiz.isSid(eid);

                        if(!flag){

                            System.out.println("没有此编号的员工存在，请重新选择！");

                            break;

                        }

                        ebiz.delById(eid);//删除

                        break;

                    case 4:

                        System.out.println("员工信息>>查找>>");

                        System.out.println("输入员工编号:");

                        eid=input.nextInt();

                        ebiz.findById(eid);//查找

                        break;

                    case 5:

                        System.out.println("员工信息>>显示>>");

                        ebiz.findAll();

                        break;

                    case 0:

                        System.out.println("谢谢使用，系统退出！");

                        System.exit(0);

                        break;

                    default:

                        System.out.println("请输入0-5之间的数字！");

                        break;

                }

            } catch (Exception e) {

                System.out.println("请输入正确的选择！");

                input=null;

                input=new Scanner(System.in);

            }

        }

    }

}

  1. 运行MainEmp.java

package com.main;

import com.action.EmpAction;

public class MainEmp {

    public static void main(String[] args) {

        new EmpAction().showMenu();

    }

}

版权声明：本文为zhhlk原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接和本声明。