HTTPx Proxy

Open the "Settings" application via "Start" and go to "Network and Internet". Here, in the "Proxy" section, find the "Manual Proxy Configuration" column. Move the slider to "On" and carefully enter the IP address and port of the proxy, then click "Save".

Data parsing in most cases refers to the collection of technical or other information. For example, a local proxy server can be used for parsing "log data". That is, information about the work of the site, the application, which in the future will be useful for developers to find and fix various bugs.

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 trying to integrate Selenium into a Java project, you'll need to use the WebDriver for Java API. Here's a step-by-step guide on how to set up Selenium with a Java project

Add Selenium dependencies to your project:

If you're using Maven, add the following dependencies to your pom.xml file:

    
        org.seleniumhq.selenium
        selenium-java
        3.141.59
    
    
        org.seleniumhq.selenium
        selenium-chrome-driver
        3.141.59
    

If you're using Gradle, add the following dependencies to your build.gradle file:

dependencies {
    implementation 'org.seleniumhq.selenium:selenium-java:3.141.59'
    implementation 'org.seleniumhq.selenium:selenium-chrome-driver:3.141.59'
}

Create a Java class for your Selenium test:

Create a new Java class for your test, for example, DropdownExample.java.

Write the test code:

Here's a simple example of how to write a test that selects an option from a drop-down menu:

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;

public class DropdownExample {
    public static void main(String[] args) {
        // Set the path to the ChromeDriver executable
        System.setProperty("webdriver.chrome.driver", "/path/to/chromedriver");

        // Create a new instance of the ChromeDriver
        WebDriver driver = new ChromeDriver();

        // Navigate to the webpage containing the drop-down menu
        driver.get("http://example.com");

        // Locate the drop-down menu element using its ID
        WebElement dropDown = driver.findElement(By.id("dropdown-menu-id"));

        // Create a Select object to interact with the drop-down menu
        Select select = new Select(dropDown);

        // Select an option from the drop-down menu by its value attribute
        select.selectByValue("option-value");

        // Close the WebDriver instance
        driver.quit();
    }
}

Run the test:

You can run your test using your preferred Java IDE or by using the command line. If you're using Maven, you can run your test with the following command:

mvn test

If you're using Gradle, you can run your test with the following command:

gradle test

This should help you integrate Selenium with your Java project and execute a test that selects an option from a drop-down menu. Make sure to replace "/path/to/chromedriver" with the actual path to your ChromeDriver executable and "http://example.com" with the URL of the webpage containing the drop-down menu.

In Scrapy, you can control the caching behavior of requests made by rules in your spider by adjusting the dont_cache attribute in the Rule object. The dont_cache attribute, when set to True, indicates that the requests matched by the rule should not be cached.

Here's an example of how you can use dont_cache in a CrawlSpider:

from scrapy.linkextractors import LinkExtractor
from scrapy.spiders import CrawlSpider, Rule

class MySpider(CrawlSpider):
    name = 'my_spider'
    allowed_domains = ['example.com']
    start_urls = ['http://example.com']

    rules = (
        # Example Rule with dont_cache set to True
        Rule(LinkExtractor(allow=('/page/')), callback='parse_page', follow=True, dont_cache=True),
    )

    def parse_page(self, response):
        # Your parsing logic for individual pages goes here
        pass

- The spider is defined as a CrawlSpider.
- The Rule is created with LinkExtractor to match URLs that contain '/page/' in them.
- The dont_cache=True attribute is set to True in the Rule, indicating that requests matched by this rule should not be cached.

By setting dont_cache to True, Scrapy will make sure that requests matched by this rule will be fetched without considering the cache. This is useful when you want to ensure that each request to the specified URLs results in a fresh response, bypassing any cached data.