package com.bjsxt.socket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Scanner;

/**
 * 发送信息线程
 */
class ClientSend extends Thread{
    private Socket socket;
    ClientSend(Socket socket){
        this.socket = socket;
    }

    @Override
    public void run() {
        this.sendMsg();
    }
    /**
     * 发送消息
     */
    private void sendMsg(){
        Scanner scanner = null;
        PrintWriter pw = null;
        try {
            scanner  = new Scanner(System.in);
            pw = new PrintWriter(this.socket.getOutputStream());
            String str = scanner.nextLine();
            while (true){
                if ("exit".equals(str)){
                    break;
                }
                pw.println(str);
                pw.flush();
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if (pw!=null){
                pw.close();
            }
            if (scanner!=null){
                scanner.close();
            }
        }

    }
}
/**
 * 接受消息线程
 */
class ClientReceive extends Thread{
    private Socket socket;
    ClientReceive(Socket socket){
        this.socket = socket;
    }
    @Override
    public void run() {
        this.receiveMsg();
    }
    /**
     * 接受消息
     */
    private void receiveMsg(){
        BufferedReader br = null;
        try {
            br = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));
            while (true){
                String clientStr = br.readLine();
                if ("exit".equals(clientStr)){
                    break;
                }
                System.out.println("客户端说："+clientStr);
            }


        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if (br!=null){
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}
public class ChatSocketClient {
    public static void main(String[] args) {
        try {
            Socket socket = new Socket("127.0.0.1",8888);
            System.out.println("连接成功！");
            new ClientReceive(socket).start();
            new ClientSend(socket).start();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

老师，为啥我这里死循环了，大家都用的where（true）了呀，而且我前面的双向通信和单向都用的了where（true）

和老师写的差不多，到点对点练习就死循环了

请问安装mysqlclient只是为了简化命令python manage.py吗？我在操作时，更改了DATABASES中的内容时就会提示：Did you install mysqlclient or MySQL-python?

执行安装mysqlclient命令（视频中pip3 install mysqlclient，为什么是pip3，我试了pip install mysqlclient，好像效果都一样，没能安装成功，提示的错误也一样，如下：）

(venv) D:\PycharmProjects\zhuce>pip3 install mysqlclient

Collecting mysqlclient

  Using cached https://files.pythonhosted.org/packages/f4/f1/3bb6f64ca7a429729413e6556b7ba5976df06019a5245a43d36032f1061e/mysqlclient-1.4.2.post

1.tar.gz

Installing collected packages: mysqlclient

  Running setup.py install for mysqlclient ... error

    Complete output from command D:\PycharmProjects\zhuce\venv\Scripts\python.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\ThinkP

ad\\AppData\\Local\\Temp\\pip-install-a58bcz2e\\mysqlclient\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n',

 '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record C:\Users\ThinkPad\AppData\Local\Temp\pip-record-j4b8_u4b\install-record

.txt --single-version-externally-managed --compile --install-headers D:\PycharmProjects\zhuce\venv\include\site\python3.6\mysqlclient:

    C:\Users\ThinkPad\AppData\Local\Programs\Python\Python36-32\lib\distutils\dist.py:261: UserWarning: Unknown distribution option: 'long_descr

iption_content_type'

      warnings.warn(msg)

    running install

    running build

    running build_py

    creating build

    creating build\lib.win32-3.6

    creating build\lib.win32-3.6\MySQLdb

    copying MySQLdb\__init__.py -> build\lib.win32-3.6\MySQLdb

    copying MySQLdb\_exceptions.py -> build\lib.win32-3.6\MySQLdb

    copying MySQLdb\compat.py -> build\lib.win32-3.6\MySQLdb

    copying MySQLdb\connections.py -> build\lib.win32-3.6\MySQLdb

    copying MySQLdb\converters.py -> build\lib.win32-3.6\MySQLdb

    copying MySQLdb\cursors.py -> build\lib.win32-3.6\MySQLdb

    copying MySQLdb\release.py -> build\lib.win32-3.6\MySQLdb

    copying MySQLdb\times.py -> build\lib.win32-3.6\MySQLdb

    creating build\lib.win32-3.6\MySQLdb\constants

    copying MySQLdb\constants\__init__.py -> build\lib.win32-3.6\MySQLdb\constants

    copying MySQLdb\constants\CLIENT.py -> build\lib.win32-3.6\MySQLdb\constants

    copying MySQLdb\constants\CR.py -> build\lib.win32-3.6\MySQLdb\constants

    copying MySQLdb\constants\ER.py -> build\lib.win32-3.6\MySQLdb\constants

    copying MySQLdb\constants\FIELD_TYPE.py -> build\lib.win32-3.6\MySQLdb\constants

    copying MySQLdb\constants\FLAG.py -> build\lib.win32-3.6\MySQLdb\constants

    running build_ext

    building 'MySQLdb._mysql' extension

    error: Microsoft Visual C++ 14.0 is required. Get it with "Microsoft Visual C++ Build Tools": http://landinghub.visualstudio.com/visual-cpp-

build-tools

    ----------------------------------------

Command "D:\PycharmProjects\zhuce\venv\Scripts\python.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\ThinkPad\\AppData\\Local\\Temp

\\pip-install-a58bcz2e\\mysqlclient\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(co

mpile(code, __file__, 'exec'))" install --record C:\Users\ThinkPad\AppData\Local\Temp\pip-record-j4b8_u4b\install-record.txt --single-version-ex

ternally-managed --compile --install-headers D:\PycharmProjects\zhuce\venv\include\site\python3.6\mysqlclient" failed with error code 1 in C:\Us

ers\ThinkPad\AppData\Local\Temp\pip-install-a58bcz2e\mysqlclient\

You are using pip version 10.0.1, however version 19.1.1 is available.

You should consider upgrading via the 'python -m pip install --upgrade pip' command.

直接写关闭ResultSet、Statement、Connection，前面的关闭Connection和Statement方法可以不再写吗？

class Person:

  def __init__(self,name,age):

    self.name = name

    self.__age = age

  def __str__(self):

    '''将对象转化成一个字符串，一般用于print方法'''

    print("重写__str__方法")

    return "名字是：{0},年龄是{1}".format(self.name,self.__age)

p = Person("高淇",18)

print(p)

s = str(p)

老师我想问一下为什么print(p)会直接调用__str__(self)方法，一般调用方法不都应该是p.xxx方法吗？是因为__str__(self)是无参的吗？类的所有无参方法都会自动调用吗？

在这个图里面，"hello"这个链表里面，他的上一个链表是"java"还是first的地址？

自动提示里面没有contextConfigLocation

如果手动输入contextConfigLocation配置启动tomcat时会报错

1、老师您好，部署consumer时，运行tomcat7:run 报错如下。详细错误在附件里。老师帮忙给看下吧。百度好久没有答案。

我用视频里的t就能解密，但拿源代码的t就不行了，这是为什么

为什么我这两个不能一块打出呢

public class TestOperater{

public static void main(String[] args){

int a = 50;

long b = 12;

long c = a+b;

System.out.println(c);

double d=5.12;

int d2=65/3;

double d3 = d/4;

int e=85%6;

System.out.println(d2);

System.out.println(d3);

System.out.println(e);

int g = 12;

g++;

System.out.println(g);

int f = 32;

f--;

g = 6;

int h = g++;

int i = g--;

System.out.println(h,i);

public Vehicle getvehicle(){

        return null;

}老师

这个方法是构造方法吗，如果是为什么与类名不同，如果不是为什么没有返回值类型而且Vehicle首字母大写

老师，在head 标签中的meta标签是这样写的吗？
<head>
    <meta><meta>
</head>

还是 
<head>
        <meta></meta>


</head>

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '= balance + 500 where accountname = 'lisi'' at line 1

老师我运行完变成这样了

b = list(x*2 for x in range(6) )
print(b)
[0, 2, 4, 6, 8, 10]

c = [x*2 for x in range(6) if x%2 ==0]
print(c)
[0, 4, 8]

老师，我看了其他问答，还是不太理解c的值为什么没有2/6/10 这些都是2的倍数，x%2余数都是0吧？ 

老师为啥我这个运行后的文件是这个样的

老师，为什么我用迭代器读取文件时多加了一行，打印的文件内容就只有个别行了呢？代码是这样的

with open（'2009.txt','r',encoding = 'utf-8'）as f:
    for a in f:
        a = f.readline()#####多加的那一行
        print(a,end = '')