这两个类有没有快捷的记忆方式啊

老师,idea怎么找不到相对路径，自己在网上找了一些资料也没搞明白

老师，我想问一下当线程池里面有1个以上的线程同时运行时，这里Runnable任务的运行结果的顺序是不是就肯定不能保证。有没有方法可以让运行速度变快，又能让结果是按顺序显示的。

老师我代码应该没有写错呀，但是为什么还是会报错呢？

package com.bjsxt.network_programming;

import java.io.*;
import java.net.URL;

public class TestURL2 {
    public static void main(String[] args) throws IOException {
        /**
         * 网络爬虫
         * （1）从网络上获取资源www.baidu.com
         * （2）存储到本地
         */
//创建URL对象
        URL url=new URL("https://www.baifu.com/");//主页资源

        //获取字节流
        InputStream is=url.openStream();
        //缓存流
        BufferedReader br=new BufferedReader(new InputStreamReader(is,"utf-8"));
        //存储到本地
        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(new FileOutputStream("index.html"),"utf-8"));
        //边读边写
        String line =null;
        while ((line=br.readLine())!=null){
            bw.write(line);
            bw.newLine();
            bw.flush();
        }
        //关闭流

        bw.close();
        br.close();

    }
}

Exception in thread "main" java.net.ConnectException: Connection timed out: connect

at java.net.DualStackPlainSocketImpl.connect0(Native Method)

at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)

at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)

at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)

at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)

at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)

at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)

at java.net.Socket.connect(Socket.java:589)

at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:666)

at sun.security.ssl.BaseSSLSocketImpl.connect(BaseSSLSocketImpl.java:173)

at sun.net.NetworkClient.doConnect(NetworkClient.java:180)

at sun.net.www.http.HttpClient.openServer(HttpClient.java:463)

at sun.net.www.http.HttpClient.openServer(HttpClient.java:558)

at sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:264)

at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:367)

at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:191)

at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1156)

at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1050)

at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:177)

at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1564)

at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1492)

at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:263)

at java.net.URL.openStream(URL.java:1045)

at com.bjsxt.network_programming.TestURL2.main(TestURL2.java:17)

Process finished with exit code 1

try catch 和抛出异常的疑问：

以下2段代码，都能往磁盘写文件，在处理异常时，用try catch和抛出异常都能正常写文件，2者在用法上有什么规则或者要求吗？抛出异常感觉代码会更简洁，

import java.io.FileWriter;
import java.io.IOException;
public class TestFileWrite2 {
    public static void main(String[] args) throws IOException {
        FileWriter writer=new FileWriter("G:\\test5.txt");
        writer.write("hello,python");
        if(writer!=null) {
            writer.close();
        }
    }
}

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

import java.io.IOException;
public class TestFileWriter {
    public static void main(String[] args) {
        //创建对象
        FileWriter writer=null;
        try {
            writer=new FileWriter("G:\\test2.txt");
            //写数据
            writer.write("hello,java");//写到的是缓冲区，不关闭不会写到文件里
            // writer.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            //
            try {
                if(writer!=null)
                writer.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}

老师有个空指针求看

老师，我没用那个 开关boolean 我这样写行不行啊

老师你好视频里面说join()是调用他的线程会阻塞，main线程被阻塞了，意思就是main线程与t是调用与被调用的关系？main的优先级比t高是吗？

老师,jdk直接都弄到15了,eclipse还是安装不上啊

为什么str2==str5会输出false？

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

/**
 * 发送消息的线程
 */
class Send1 extends Thread{
    private Socket socket;
    private Scanner scanner;
    public Send1(Socket socket,Scanner scanner){
        this.socket = socket;
        this.scanner = scanner;
    }

    @Override
    public void run() {
        this.sendMsg();
    }
    /**
     * 发送消息
     */
    private void sendMsg(){
        //创建向对方输出消息的流对象
        try (PrintWriter pw = new PrintWriter(socket.getOutputStream())){
            while (true){
                String msg = scanner.nextLine();
                pw.println(msg);
                pw.flush();
            }
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}

/**
 * 接收消息的线程
 */
class Receive1 extends Thread{
    private Socket socket;
    public Receive1(Socket socket){
        this.socket = socket;
    }

    @Override
    public void run() {
        this.receiveMsg();
    }
    /**
     * 接收消息
     */
    private void receiveMsg(){
        //创建用于接收对方发送消息的流对象
        try(BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()))){
            while(true){
                String msg = br.readLine();
                System.out.println("他说："+msg);
            }
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}
public class GoodTCP {
    public static void main(String[] args) {
        Scanner scanner = null;
        ServerSocket serverSocket = null;
        Socket socket = null;
        try {
            //键盘输入对象
            scanner  = new Scanner(System.in);
            System.out.println("请输入：server,<port> 或者：<ip>,<port>");
            String str = scanner.nextLine();
            String[] arr = str.split(",");
            if ("server".equals(arr[0])){
                //启动服务器
                System.out.println("TCP Server Listen at "+arr[1]+"......");
                serverSocket = new ServerSocket(Integer.parseInt(arr[1]));
                socket = serverSocket.accept();
                System.out.println("连接成功！");
            }else{
                //启动客户端
                socket = new Socket(arr[0],Integer.parseInt(arr[1]));
                System.out.println("连接成功！");
            }
            //启动发送消息的线程
            new Send1(socket,scanner).start();
            //启动接收消息的线程
            new Receive1(socket).start();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if(serverSocket != null){
                try {
                    serverSocket.close();
                }catch (IOException e){
                    e.printStackTrace();
                }
            }
        }
    }
}

请输入：server,<port> 或者：<ip>,<port>

server，8888

java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1

at GoodTCP.main(GoodTCP.java:88)

老师，这是数组越界吗？我该怎么解决呢？

老师，这个在主线程的睡眠是让哪个子线程睡眠？

添加了在关闭前加个等待时间，还是报错

问题一：Server运行，游览器无响应啊？

问题二：StringBuilder sb，添加了那么多字符串的意义在哪里，响应只显示“成功”，其余的是被游览器解析的吗？

package cn.bjsxt.server;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {//服务器，启动和停止服务
	private ServerSocket server;
	public static void main(String[] args){
		Server server = new Server();//创建服务器对象
		server.start();
	}
	public void start(int port){
		try {
			server = new ServerSocket(port);
			this.receive();//调用接收请求信息的方法
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	public void start(){
		this.start(8888);
	}
	private void receive() {
		
		try {
			//(1)监听
			Socket client = server.accept();
			//获取用户的请求
			/*InputStream is = client.getInputStream();
			byte [] buf = new byte[20480];
			int len = is.read(buf);
			System.out.println(new String(buf,0,len));*/
			Request req = new Request(client.getInputStream());
			//req.show();
			/**做出响应*/
			StringBuilder sb = new StringBuilder();
			sb.append("HTTP/1.1").append(" ").append(200).append(" ").append("OK").append("\r\n");
			sb.append("Content-Type:text/html;charset=utf-8").append("\r\n");
			//内容
			String str="<html><head><title>响应结果</ritle></head><body>成功</body></html>";
			sb.append("Content-Length:"+str.getBytes("utf-8").length).append("/r/n");
			sb.append("\r\n");
			sb.append(str);
			//通过输出流发送出去
			BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(client.getOutputStream(),"utf-8"));
			bw.write(sb.toString());
			bw.flush();
			bw.close();
			
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	public void stop(){
		
	}

}