Is Java easy to learn? Confidence, perseverance and courage are dedicated to all of you who are constantly working hard for your dreams

Posted by mr_mind on Tue, 21 Dec 2021 05:13:26 +0100

1, 2021 year end summary

1. CSDN second season Star Program mentor

2. Founder of Nezha community

The hard-working little partners are all clocking in, including daily lonely clocking in, daily reading clocking in, daily video clocking in, etc. don't you join in the study?
Punch in 100 days and become a devil if you don't become a God.

3,Join Nezha community and learn to punch in. You can't stop at all

2, How to learn Java

1. If the foundation is not firm, the earth will shake and the mountains will shake

Steady and steady, step by step, stick to blogging in CSDN, continue to output, and improve the day.

2,Java foundation tutorial series

3. Java basic thought map

4. I also want to join. I want to make an online consultation through UDP, and ask Nezha.

3, Implementing multi thread online consultation with UDP

1. Sender

package com.guor.ipidea;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketException;

public class TalkSend implements Runnable {
    DatagramSocket socket = null;
    BufferedReader reader = null;
    private int fromPort;
    private String toIP;
    private int toPort;

    public TalkSend(int fromPort, String toIP, int toPort) {
        this.fromPort = fromPort;
        this.toIP = toIP;
        this.toPort = toPort;

        try {
            socket = new DatagramSocket(fromPort);
            reader = new BufferedReader(new InputStreamReader(System.in));
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        while (true){
            String data = null;
            try {
                data = reader.readLine();
                byte[] datas = data.getBytes();
                DatagramPacket packet = new DatagramPacket(datas,0,datas.length,new InetSocketAddress(this.toIP,this.toPort));
                socket.send(packet);
                if(data.equals("bye")){
                    break;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        socket.close();
    }
}

2. Receiving end

package com.guor.ipidea;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;

public class TalkReceive implements Runnable{
    DatagramSocket socket = null;
    private int port;
    private String msgFrom;

    public TalkReceive(int port, String msgFrom) {
        this.port = port;
        this.msgFrom = msgFrom;

        try {
            socket = new DatagramSocket(port);
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        while (true){
            try {
                //Ready to receive package
                byte[] container = new byte[1024];
                DatagramPacket packet = new DatagramPacket(container,0,container.length);
                //Blocking receiving package
                socket.receive(packet);
                //Disconnect bye
                byte[] data = packet.getData();
                String receiveData = new String(data,0,data.length);
                System.out.println(msgFrom + ":" + receiveData);
                if(receiveData.equals("bye")){
                    break;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        socket.close();
    }
}

3,ipidea

package com.guor.ipidea;

public class IpIdea {
    public static void main(String[] args) {
        new Thread(new TalkSend(7777,"localhost",9999)).start();
        new Thread(new TalkReceive(8888,"nezha")).start();
    }
}

4. Nezha

package com.guor.ipidea;

public class Nezha {
    public static void main(String[] args) {
        new Thread(new TalkSend(5555,"localhost",8888)).start();
        new Thread(new TalkReceive(9999,"ipidea")).start();
    }
}

4, Give a peach for a plum

1. Nezha gives you a song "little companion dragon children's song: Merry Christmas"

Christmas is coming soon. Primary school students want to listen to children's songs, but they are charged. Nezha had an idea to teach you to use Java net. Download the URL and listen.

2. Get the address of "little companion dragon children's song: Merry Christmas"

3. Code example

package com.guor.test;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class MerryTest {
    public static void main(String[] args) throws IOException {
        URL url = new URL("https://vd2.bdstatic.com/mda-mm02j05avh9knriq/sc/cae_h264_nowatermark/1638341959033134772/mda-mm02j05avh9knriq.mp4?v_from_s=hkapp-haokan-hbe&amp;auth_key=1639838362-0-0-0ae86199711f5fcbe20fba556a907433&amp;bcevod_channel=searchbox_feed&amp;pd=1&amp;pt=3&amp;abtest=3000203_5&amp;klogid=0562178188");
        HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
        InputStream inputStream = urlConnection.getInputStream();
        FileOutputStream fileOutputStream = new FileOutputStream("Merry Christmas.mp4");
        byte[] buffer = new byte[1024];
        int len;
        while ((len=inputStream.read(buffer))!=-1){
            fileOutputStream.write(buffer,0,len);
        }
        fileOutputStream.close();
        inputStream.close();
        urlConnection.disconnect();
    }
}

4. Download to local

5. Local play

5, Is it risky to download it casually?

1. How to solve it?

Because we collect data too fast, which puts too much pressure on the other party's server. The other party can trace back and find us easily, which will lead to our ip being blocked.
If we want to stop being blocked, we need to replace the IP to grab data information. So how to solve this problem?

Found an http
Crawl ip
Verify ip validity
Record ip

2. Introduction to ipidea

ipidea is an overseas crawler agent, providing overseas residential ip and overseas static ip. It is mainly engaged in data collection business and maintains long-term cooperation with multiple data collection enterprises. It provides 90 million ip resources and can customize the ip rotation time according to the capture requirements, so as to avoid being blocked by the website. It supports account secret authentication and API extraction to extract ip resources. The most important thing is to support free testing.

The world's leading Internet big data IP Resources

3. ipidea generates api links, which can be applied by copying links

Common or transparent ip will waste a lot of time while testing and extracting ip. Finally, it may be invalid ip. Only proxy ip can be used in a simpler way. Its practicability, stability and security can be guaranteed. Use IPIDEA for ip extraction.

4. Generate proxy ip operation usage

During server maintenance or self-contained proxy ip, many of them will not be maintained. Therefore, many proxy ip appear. The use of proxy ip is relatively simple. If there are problems, you can feed back to the agent in time and find technicians to solve them. Crawlers are used to quickly complete the work requirements. Using agents can save working time and complete the work quickly.

6, 2022, beautiful vision

1. Publishing black books

Java learning route summary, brick movers counter attack Java Architects

Brick movers counter attack Java architects is also trying to catch up with the draft. Nezha's first black book will meet you in half a year and wait and see.