链接超时，

配置也改了，这是为什么

老师请问下第三行为什么要用format()，像图上这样也是一样的结果？

[es@localhost opt]$ ES_JAVA_OPTS="-Xms512m -Xmx512m" /usr/local/elasticsearch/bin/elasticsearch -d

warning: usage of JAVA_HOME is deprecated, use ES_JAVA_HOME

Future versions of Elasticsearch will require Java 11; your Java version from [/usr/local/jdk1.8/jre] does not meet this requirement. Consider switching to a distribution of Elasticsearch with a bundled JDK. If you are already using a distribution with a bundled JDK, ensure the JAVA_HOME environment variable is not set.

老师，我的是不是需要把jdk8改成jdk11就可以了？

老师 这里为什么不可以直接过滤呢？

那个window=none是什么意思

老师解决了已经，不需要看了

SELECT e.LAST_NAME,e.DEPARTMENT_ID 

from employees e

 WHERE e.DEPARTMENT_ID=(SELECT e1.DEPARTMENT_ID 

from employees e1  where e1.last_name"Fox");

老师我这串代码哪里有问题呀

老师我这里rz命令不能用，是什么原因啊

[root@localhost ~]# rz

-bash: rz: command not found

com.itbaizhan.SocketDemo;

java.io.BufferedReader;
java.io.InputStreamReader;
java.io.PrintWriter;
java.net.ServerSocket;
java.net.Socket;
java.util.Scanner;
Send1 Thread{
    Socket ;
    Scanner ;
    Send1(Socket socket,Scanner scanner){
        .=scanner;
        .=socket;
    }

    run() {
        .SendMsg();
    }
    SendMsg(){
        (PrintWriter pw=PrintWriter(.getOutputStream());){
            (){
                String msg=.nextLine();
                pw.println(msg);
                pw.flush();
            }
        }
        (Exception e){
            e.printStackTrace();}
    }
}
Receive1 Thread{
    Socket ;
    Receive1(Socket socket){
        .=socket;
    }

    run() {
        .receiveMsg();
    }
    receiveMsg(){
        (BufferedReader br=BufferedReader( InputStreamReader(.getInputStream()));
        ){
            (){
                String msg=br.readLine();
                System..println(+msg);
            }
        }
        (Exception e){
            e.printStackTrace();}

    }
}
GoodTCP {
    main(String[] args) {
        ServerSocket serverSocket=;
        Socket socket=;
        {
            Scanner scanner=Scanner(System.);
            System..println();
            String str= scanner.nextLine();
            String[] arr=str.split();
            String[] split=str.split();
            (.equals(arr[])){
                System..println(+arr[]+);
                serverSocket =ServerSocket(Integer.(arr[]));
                 socket = serverSocket.accept();

            }{
                socket =Socket(arr[],Integer.(arr[]));
                System..println();

            }
            Send1(socket,scanner).start();
            Receive1(socket).start();
        }
        (Exception e){
            e.printStackTrace();
        }{
            (serverSocket!=){
                {
                    serverSocket.close();
                }(Exception e){
                    e.printStackTrace();
                }
            }
        }
    }
}

com.itbaizhan.SocketDemo;

java.io.BufferedReader;
java.io.InputStreamReader;
java.io.PrintWriter;
java.net.ServerSocket;
java.net.Socket;

Msg Thread{
    Socket ;
    Msg(Socket socket){
        .= socket;
    }
    run() {
        .msg();
    }

    msg(){
        (BufferedReader br = BufferedReader(InputStreamReader(..getInputStream()));
            PrintWriter pw = PrintWriter(..getOutputStream())){
            (){
                pw.println(br.readLine()+);
                pw.flush();
            }
        }(Exception e){
            e.printStackTrace();
            System..println(..getInetAddress()+);
        }
    }
}
EchoServer {
    main(String[] args) {
        (ServerSocket serverSocket = ServerSocket()){
            (){
                Socket socket = serverSocket.accept();
                Msg(socket).start();
            }
        }(Exception e){
            e.printStackTrace();
        }
    }
}

不知道为什么会报错，代码运行没问题。

老师我这是什么问题啊

公共类 TestInt{

public static void main （String[] args）{

int a = 100;

int b = 015;

int c =  0cff;

int d = 0b10010101011;

System.out.println（a）;

System.out.println（b）;

System.out.println（c）;

System.out.println（d）;

}

}

老师橡皮擦利用减4，加4是什么意思？

老师为什么要给火箭直线加一个arrow=LAST？这是什么意思？

self.fgcolor = "#ff0000"

老师这后面的颜色可以直接写成red红色吗？