USAvideos Proxy

Qt primarily focuses on providing tools and libraries for GUI development, networking, and other application-level features. While it includes facilities for working with XML through classes like QXmlStreamReader and QXmlStreamWriter, these are more geared toward parsing XML rather than HTML.

For HTML parsing, especially when using XPath expressions, you might need to consider additional libraries or tools. One common choice is to use a third-party library like Gumbo or htmlcxx. These libraries are not part of the Qt framework, but they can be used alongside Qt to handle HTML parsing.

Here's a basic example using htmlcxx for HTML parsing:

#include 
#include 
#include 

int main(int argc, char *argv[]) {
    QCoreApplication a(argc, argv);

    std::string htmlData = "
Hello, world!
";

    htmlcxx::HTML::ParserDom parser;
    tree dom = parser.parseTree(htmlData);

    // Example XPath query
    std::string xpathExpression = "//p/span";
    std::vector::iterator> result;
    htmlcxx::XPath::NodeSet nodeSet;
    htmlcxx::XPath::Parser xpathParser;
    xpathParser.compile(xpathExpression.c_str(), &nodeSet);

    for (tree::iterator it = dom.begin(); it != dom.end(); ++it) {
        nodeSet.evaluate(*it);
        if (nodeSet.size() > 0) {
            result.push_back(it);
        }
    }

    // Output the result
    for (auto &it : result) {
        std::cout << "Match found: " << htmlcxx::HTML::toPlainText(it->begin(), it->end()) << std::endl;
    }

    return a.exec();
}

In this example, I've used htmlcxx for HTML parsing and XPath queries. Note that you need to include the htmlcxx library in your project.

If you're parsing XML in Golang and the result is not being saved in the structure as expected, there might be issues with your XML parsing code. Below is a simple example demonstrating how to parse XML and save the result in a structure using the encoding/xml package in Golang.

Assuming you have the following XML structure:

    John Doe
    30

And you want to parse it into the following Go structure:

package main

import (
	"encoding/xml"
	"fmt"
)

type User struct {
	Name string `xml:"name"`
	Age  int    `xml:"age"`
}

func main() {
	xmlData := `John Doe30`

	var user User

	// Unmarshal XML into the User structure
	err := xml.Unmarshal([]byte(xmlData), &user)
	if err != nil {
		fmt.Println("Error:", err)
		return
	}

	// Print the result
	fmt.Printf("Name: %s\nAge: %d\n", user.Name, user.Age)
}

In this example:

The User struct tags (e.g., xml:"name") indicate the mapping between the XML elements and the fields in the structure.

xml.Unmarshal is used to parse the XML data and populate the User structure.

Ensure that your XML data and struct tags match correctly. If the XML structure or tags are different, you might encounter issues with parsing.

If you continue to face problems, please provide more details or your specific code for further assistance.

If you are parsing a site using JSoup in a Java application and you want to introduce a delay between requests to avoid being blocked or rate-limited by the website, you can use Thread.sleep to pause the execution for a specified duration. Here's a basic example

First, make sure you have the JSoup library included in your project. If you're using Maven, you can add the following dependency to your pom.xml:

    org.jsoup
    jsoup
    1.14.3 

Now, here's an example Java program using JSoup with a delay between requests:

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;

import java.io.IOException;

public class WebScraperWithDelay {

    public static void main(String[] args) {
        // Replace with the URL you want to scrape
        String url = "https://example.com";
        
        // Number of milliseconds to wait between requests
        long delayMillis = 2000; // 2 seconds
        
        try {
            for (int i = 0; i < 5; i++) {
                // Make the HTTP request using JSoup
                Document document = Jsoup.connect(url).get();

                // Process the document as needed
                System.out.println("Title: " + document.title());

                // Introduce a delay between requests
                Thread.sleep(delayMillis);
            }
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }
}

In this example:

1. Jsoup.connect(url).get() is used to make an HTTP request and retrieve the HTML document from the specified URL.
2. Thread.sleep(delayMillis) introduces a delay of 2 seconds between requests. You can adjust the value of delayMillis based on your needs.

Building a chain of proxies in Selenium involves configuring a WebDriver with a Proxy object that represents a chain of proxies. Here's an example using Python with Selenium and the Chrome WebDriver:

from selenium import webdriver
from selenium.webdriver.common.proxy import Proxy, ProxyType

# Create a Proxy object for the first proxy in the chain
proxy1 = Proxy()
proxy1.http_proxy = "http://proxy1.example.com:8080"
proxy1.ssl_proxy = "http://proxy1.example.com:8080"
proxy1.proxy_type = ProxyType.MANUAL

# Create a Proxy object for the second proxy in the chain
proxy2 = Proxy()
proxy2.http_proxy = "http://proxy2.example.com:8080"
proxy2.ssl_proxy = "http://proxy2.example.com:8080"
proxy2.proxy_type = ProxyType.MANUAL

# Create a Proxy object for the final proxy in the chain
proxy3 = Proxy()
proxy3.http_proxy = "http://proxy3.example.com:8080"
proxy3.ssl_proxy = "http://proxy3.example.com:8080"
proxy3.proxy_type = ProxyType.MANUAL

# Create a chain of proxies
proxies_chain = f"{proxy1.proxy, proxy2.proxy, proxy3.proxy}"

# Set up ChromeOptions with the proxy chain
chrome_options = webdriver.ChromeOptions()
chrome_options.add_argument(f"--proxy-server={proxies_chain}")

# Create the WebDriver with ChromeOptions
driver = webdriver.Chrome(options=chrome_options)

# Now you can use the driver with the proxy chain for your automation tasks
driver.get("https://example.com")

# Close the browser window when done
driver.quit()

In this example:

Three Proxy objects (proxy1, proxy2, and proxy3) are created, each representing a different proxy in the chain. You need to replace the placeholder URLs (http://proxy1.example.com:8080, etc.) with the actual proxy server URLs.

The ProxyType.MANUAL option is used to indicate that the proxy settings are configured manually.

The proxies_chain variable is a comma-separated string representing the chain of proxies.

The --proxy-server option is added to ChromeOptions to specify the proxy chain.

A Chrome WebDriver instance is created with the configured ChromeOptions.

Under the parsing of goods often mean the collection of a database in which the data is entered about all the items sold in online stores. For example, the famous service e-katalog is just engaged in this type of parsing. And then it simply structures all the data obtained and publishes them on its site.