测试

package cn.test;

import java.util.Scanner;

public class Test01 {
        static Scanner sc = new Scanner(System.in);
        public static void main(String[] args) {
            System.out.print("请输入一串字符：");
            String str = sc.next();
            
            str = str.replace("wqnmlgb", "*");
            str = str.replace("ndy", "*");
            str = str.replace("dsb", "*");
            System.out.println(str);
            
        }
}

package cn.test;
import java.util.Scanner;
public class Test02 {
        static Scanner sc = new Scanner(System.in);
        public static void main(String[] args) {
            System.out.println("请输入要一组字符：");
            String old = sc.next();
            String[] gd = old.split("");
            StringBuffer xin = new StringBuffer(" ");
            for(int i = 0;i < gd.length;i++) {
                if(gd[i].matches("[0-9]")) {
                    xin.append(gd[i]);
                }
            }
            System.out.println(String.valueOf(xin));
        }
}

不会

package cn.test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
public class Test04 {
        public static void main(String[] args) {
            //读
            BufferedReader br = null;
            InputStreamReader isr = null;
            FileInputStream fis = null;
            //写
            BufferedWriter bw = null;
            FileOutputStream fos = null;
            OutputStreamWriter osw = null;
            try {
                fis = new FileInputStream("F:\\a.java");
                isr = new InputStreamReader(fis);
                br = new BufferedReader(isr);
                
                fos = new FileOutputStream("F:\\b.java");
                osw = new OutputStreamWriter(fos);
                bw = new BufferedWriter(osw);
                String str=null;
                while((str=br.readLine())!=null) {
                    bw.write(str);
                }
                bw.flush();
                System.out.println("copy完成");
            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally {
                try {
                    bw.close();
                    osw.close();
                    fos.close();
                    br.close();
                    isr.close();
                    fis.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
}

 

 

package cn.test;

import java.text.SimpleDateFormat;
import java.util.Date;

public class Test05 {
        public static void main(String[] args) {
            while(true) {
                Date date = new Date();
                SimpleDateFormat sdf = new SimpleDateFormat("hh:MM:ss");//yyyy-MM-dd    
                System.out.println(sdf.format(date));
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
}

 

 

package cn.test;

public class TestThread061 extends Thread{
        public void run() {
            for(int i = 0;i <100;i++){
                System.out.println(Thread.currentThread().getName()+"说：你是谁啊？");
            }
        }
}
package cn.test;

public class TestThread062 implements Runnable{

    @Override
    public void run() {
        for(int i = 0;i < 100;i++) {
            System.out.println(Thread.currentThread().getName()+"说：我是查水表。");
        }
        
    }

}
package cn.test;

public class Test06 {
        public static void main(String[] args) {
            TestThread061 r = new TestThread061();
            TestThread062 j = new TestThread062();
            Thread r1 = new Thread(r,"rose");
            Thread j1 = new Thread(j,"jack");
            r1.setPriority(10);
            j1.setPriority(9);
            r1.start();
            j1.start();
        }
}

不能正常对话（待完善）

package cn.test;

public class Penguin {
        private String name;
        private String sex;
        public Penguin() {
            super();
        }
        public Penguin(String name, String sex) {
            super();
            this.name = name;
            this.sex = sex;
        }
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public String getSex() {
            return sex;
        }
        public void setSex(String sex) {
            this.sex = sex;
        }
        
}
package cn.test;

import java.util.ArrayList;
import java.util.List;

public class Test07 {
    static {
        
    }
        public static void main(String[] args) {
            Penguin  p1 = new Penguin ("欧欧", "Q仔");
            Penguin  p2 = new Penguin ("亚亚", "Q妹");
            Penguin  p3 = new Penguin ("菲菲", "Q妹");
            Penguin  p4 = new Penguin ("美美", "Q妹");
            List<Penguin>list = new ArrayList<>();
            
            list.add(p1);
            list.add(p2);
            list.add(p3);
            list.add(p4);
            System.out.println("共有"+list.size()+"只企鹅");
            
            
            for(Penguin qie:list) {
                System.out.println(qie.getName()+"\t"+qie.getSex());
            }
            for(int i = 0;i < list.size();i++) {
                if(list.get(i).getName().equals("菲菲")) {
                    list.remove(i);
                }
            }
            for(int i = 0;i < list.size();i++) {
                if(list.get(i).getName().equals("美美")) {
                    list.remove(i);
                }
            }
            System.out.println("删除后还有"+list.size()+"只企鹅");
            for(Penguin qie:list) {
                System.out.println(qie.getName()+"\t"+qie.getSex());
            }
        
            for(int i = 0;i < list.size();i++) {
                if(!list.get(i).getName().equals("美美")) {
                    System.out.println("不存在美美的信息");
                    break;
                }
            }
            
            
        }
}

package cn.test;

import java.util.Scanner;

public class Test08 {
        static Scanner sc = new Scanner(System.in);
        public static void main(String[] args) {
            System.out.println("******欢迎进入注册系统******");
            System.out.print("请输入用户名：");
            String name= sc.next();
            for(;name.length()<3;name=sc.next()) {
                System.out.print("用户名长度小于3，请重新输入用户名：");
            }
            System.out.print("请输入注册密码：");
            String code1 = sc.next();
            for(;code1.length()<6;code1=sc.next()) {
                System.out.print("密码长度小于6位，请重新输入注册密码：");
            }
            System.out.println("请再次输入密码：");
            String code2 = sc.next();
            for(;!code1.equals(code2);code2=sc.next()) {
                System.out.print("两次密码输入不一致，请重新输入密码：");
            }
            System.out.print("注册成功，请牢记用户名和密码");
                
            
            
        }
}

 

 

package cn.test;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;

public class Test09C {
    public static void main(String[] args) {
        try {
            //创建客户端
            //发送请求到服务器
            Socket socket = new Socket("localhost",5000);
            //通过输出流发送请求
            String  info = "用户名：Levi；密码：123456";
            OutputStream os = socket.getOutputStream();//字节输出流
            byte[] infos = info.getBytes();
            os.write(infos);
            //输入流接受服务器的响应
            socket.shutdownOutput();
            InputStream is = socket.getInputStream();
            BufferedReader br = new BufferedReader(new InputStreamReader(is));
            String reply;
            while((reply = br.readLine())!=null) {
                System.out.println("服务器说："+reply);
            }
            //释放资源
            br.close();
            is.close();
            os.close();
            socket.close();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            
            e.printStackTrace();
        }
    }
}

package cn.test;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class Test09S {
    public static void main(String[] args) {
        //创建一个Socket
                try {
                    //接受客户端请求
                    ServerSocket ss = new ServerSocket(5000);//5000端口
                    //使用accept()侦听并接收到ServerSocket的连接
                    Socket socket = ss.accept();
                    //获得输入流，获得用户的请求
                    InputStream is=  socket.getInputStream();
                    BufferedReader br = new BufferedReader(new InputStreamReader(is));//？
                    String info;
                    while((info = br.readLine())!=null) {
                        System.out.println("客户端说"+info);
                    }
                    //给客户端一个响应
                    String reply = "欢迎登录";
                    //通过输出流将相应发送到客户端
                    OutputStream os = socket.getOutputStream();
                    os.write(reply.getBytes());
                    os.close();
                    
                    br.close();
                    is.close();
                    socket.close();
                    ss.close();
                } catch (IOException e) {
                    
                    e.printStackTrace();
                }
    }
}

package cn.test;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class Test10 {
    public static void main(String[] args) {
        FileInputStream fis = null;
        DataInputStream dis = null;
        FileOutputStream fos = null;
        DataOutputStream dos = null;
        try {
            //读出来
             fis = new FileInputStream("F:\\专业\\a.png");
             dis= new DataInputStream(fis);
            //写进去
             fos = new FileOutputStream("F:\\专业\\b.png");
             dos = new DataOutputStream(fos);
            int temp= -1;
            while((temp=dis.read())!=-1) {
                dos.write(temp);
            
            }
            dos.flush();
            System.out.println("复制完成");
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            try {
                fos.close();
                dis.close();
                fis.close();
                dos.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            
            
            
        }
        
        
        
    }
}

部分没有完成的看看其他同学的