第一题：

package com.io;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileWriter;import java.io.IOException;import java.io.InputStreamReader;import java.io.UnsupportedEncodingException;import java.io.Writer;public class WriterDOme2 {    public static void main(String[] args) {        InputStreamReader f = null;        BufferedReader br = null;        Writer w = null;        BufferedWriter bw = null;        try {            f = new InputStreamReader(new FileInputStream("d:/chenxiaolong/你说呢.txt"),"GBK");            w= new FileWriter("d:/chenxiaolong/我说的.txt");            br = new BufferedReader(f);            StringBuffer s = new StringBuffer();            bw = new BufferedWriter(w);            String str = null;            while((str=br.readLine())!=null) {                s.append(str);            }            System.out.println("没替换:"+s);            String a =s.toString().replace("（x）", "是小明").toString().replace("（y）", "这话");            bw.write(a);            bw.flush();            System.out.println("替换后:"+a);            br.close();            bw.close();        } catch (UnsupportedEncodingException e) {            e.printStackTrace();        } catch (FileNotFoundException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }finally {            try {                br.close();            } catch (IOException e) {                e.printStackTrace();            }        }        }}

输出结果图：

 

第二题：

package com.io;import java.io.Serializable;/** * 会员类 * @author 陈明 * */public class User implements Serializable{    private String nome;    private int ID ;    private  String mima;    public String getNome() {        return nome;    }    public void setNome(String nome) {        this.nome = nome;    }    public int getID() {        return ID;    }    public void setID(int iD) {        ID = iD;    }    public String getMima() {        return mima;    }    public void setMima(String mima) {        this.mima = mima;    }    }

package com.io;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.util.HashMap;import java.util.Map;import java.util.Scanner;/** * 登陆测试类 * @author 陈明 * */public class UserObjDome {    User user = new User();    Scanner sc = new Scanner(System.in);    Map
     
       map = new HashMap();        /**     * 系列化方法     *      * */    public void xuliehua(Map map) {        ObjectOutputStream obj = null;        FileOutputStream f = null;        try {            f = new FileOutputStream("d:/chenxiaolong/map.txt");            obj = new ObjectOutputStream(f);            obj.writeObject(map);        } catch (FileNotFoundException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }finally {            try {                obj.close();                f.close();            } catch (IOException e) {                e.printStackTrace();            }        }            }    /**     * 反序列化方法     */    public Map fanxuliehua() {        ObjectInputStream obj2 = null;        FileInputStream f2 = null;        try {            f2 = new FileInputStream("d:/chenxiaolong/map.txt");            obj2 = new ObjectInputStream(f2);            map =(Map)obj2.readObject();        } catch (FileNotFoundException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        } catch (ClassNotFoundException e) {            e.printStackTrace();        }finally {            try {                obj2.close();                f2.close();            } catch (IOException e) {                e.printStackTrace();            }                    }        return map;    }    /**     * 注册方法     *      */    public void   zhuci() {                //调用反序列化方法        Map m =fanxuliehua();        System.out.println("请输入用户命");        user.setMima(sc.next());        System.out.println("请输入登入ID");        int id=sc.nextInt();        while(true) {            if(map.containsKey(id)) {                System.out.println("ID已经存在请重新输入");            }else {                user.setID(id);                break;            }        }        System.out.println("请输入用密码");        user.setMima(sc.next());        //把信息存在Map集合中        m.put(id, user);        //调用系列化方法        xuliehua(m);    }    /**     * 登入方法     */    public void  dnenglu() {        //掉用反序列化方法                Map
      
        m =fanxuliehua();        System.out.println("请输入您的ID");        int id = sc.nextInt();                        if(map.containsKey(id)) {            System.out.println("请输入您的密码");            String  mima = sc.next();            if(mima.equals(map.get(id).getMima())) {                System.out.println("登录成功");            }else {                System.out.println("密码不正确");            }        }else {            System.out.println("没有此ID重新请输入");        }    }        /**     * 操作界面方法     */    public void jiem() {        System.out.println("请输入您要操作的功能   1，注册      2，登录");        int s =sc.nextInt();        if(s==1) {            zhuci();        }else {            dnenglu();        }    }}
      
     

package com.io;/** *  * @author 陈明 * */public class UserTest {    public static void main(String[] args) {        UserObjDome user = new UserObjDome();        user.jiem();    }}

输出结果图：