How to build a real-time web crawler with Elasticsearch and PHP-PHP Tutorial-php.cn

Home

Backend Development

PHP Tutorial

How to build a real-time web crawler with Elasticsearch and PHP

王林

Jul 07, 2023 pm 12:33 PM

phpWeb Crawlerelasticsearch

How to build a real-time web crawler using Elasticsearch and PHP

Introduction:
A web crawler is an automated program that collects information from the Internet and organizes and analyzes it. Elasticsearch is an open source search engine that provides fast, real-time search and analysis capabilities. PHP is a popular server-side scripting language. Combining Elasticsearch and PHP, we can build a real-time web crawler that scrapes data from websites and stores it in Elasticsearch for search and analysis.

Step 1: Install and configure Elasticsearch
First, we need to install and configure Elasticsearch on the server. You can download the version suitable for your operating system from the Elasticsearch official website, and install and configure it according to the official documentation.

Step 2: Set up the Elasticsearch index
In Elasticsearch, data is stored in the index. We need to define the structure and fields of the index. The following is an example index definition for storing data we crawl from the website:

PUT my_index
{
  "mappings": {
    "properties": {
      "title": {
        "type": "text"
      },
      "content": {
        "type": "text"
      },
      "url": {
        "type": "keyword"
      }
    }
  }
}

Here we define an index named "my_index", which contains "title", "content" and "url" three fields. The "title" and "content" fields are of type "text", and the "url" field is of type "keyword". You can define more fields according to your needs.

Step 3: Write PHP crawler code
Next, we will use PHP to write a simple web crawler to crawl data from the specified website and store the data in Elasticsearch. The following is an example code:

<?php

// 定义需要抓取的目标网站URL
$targetUrl = "https://www.example.com";

// 创建一个Elasticsearch客户端实例
$esClient = new ElasticsearchClient();

// 从目标网站上获取HTML内容
$htmlContent = file_get_contents($targetUrl);

// 使用正则表达式提取标题和内容
preg_match('/<title>(.*?)</title>/', $htmlContent, $titleMatches);
preg_match('/<body>(.*?)</body>/', $htmlContent, $contentMatches);

// 抓取到的数据
$title = $titleMatches[1];
$content = strip_tags($contentMatches[1]); // 去除HTML标签

// 构建文档
$document = [
    'index' => 'my_index',
    'body' => [
        'title' => $title,
        'content' => $content,
        'url' => $targetUrl
    ]
];

// 将文档存储到Elasticsearch中
$esClient->index($document);

echo "数据已成功存储到Elasticsearch中！";

?>

In this code, we first define the target website URL to be crawled. Then, an Elasticsearch client instance was created for interacting with Elasticsearch. Next, use the file_get_contents function to get the HTML content of the target website, and then use regular expressions to extract the title and content. Finally, the document is built and stored in Elasticsearch. The storage operation uses the index function provided by Elasticsearch.

Step 4: Run the crawler code
Save the above code into a PHP file and upload it to your server. Then execute the file in the terminal or command line to start running the crawler.

$ php crawler.php

The crawler will crawl data from the specified website and store it in Elasticsearch.

Conclusion:
By combining Elasticsearch and PHP, we can build a simple but powerful real-time web crawler. With the search and analysis capabilities of Elasticsearch, we can easily search and analyze the crawled data. I hope this article is helpful to you, go and try to build your own real-time web crawler!

The above is the detailed content of How to build a real-time web crawler with Elasticsearch and PHP. For more information, please follow other related articles on the PHP Chinese website!

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

PHP in Action: Real-World Examples and ApplicationsApr 14, 2025 am 12:19 AM

PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.

PHP: Creating Interactive Web Content with EaseApr 14, 2025 am 12:15 AM

PHP makes it easy to create interactive web content. 1) Dynamically generate content by embedding HTML and display it in real time based on user input or database data. 2) Process form submission and generate dynamic output to ensure that htmlspecialchars is used to prevent XSS. 3) Use MySQL to create a user registration system, and use password_hash and preprocessing statements to enhance security. Mastering these techniques will improve the efficiency of web development.

PHP and Python: Comparing Two Popular Programming LanguagesApr 14, 2025 am 12:13 AM

PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

The Enduring Relevance of PHP: Is It Still Alive?Apr 14, 2025 am 12:12 AM

PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.

PHP's Current Status: A Look at Web Development TrendsApr 13, 2025 am 12:20 AM

PHP remains important in modern web development, especially in content management and e-commerce platforms. 1) PHP has a rich ecosystem and strong framework support, such as Laravel and Symfony. 2) Performance optimization can be achieved through OPcache and Nginx. 3) PHP8.0 introduces JIT compiler to improve performance. 4) Cloud-native applications are deployed through Docker and Kubernetes to improve flexibility and scalability.

PHP vs. Other Languages: A ComparisonApr 13, 2025 am 12:19 AM

PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.

PHP vs. Python: Core Features and FunctionalityApr 13, 2025 am 12:16 AM

PHP and Python each have their own advantages and are suitable for different scenarios. 1.PHP is suitable for web development and provides built-in web servers and rich function libraries. 2. Python is suitable for data science and machine learning, with concise syntax and a powerful standard library. When choosing, it should be decided based on project requirements.

PHP: A Key Language for Web DevelopmentApr 13, 2025 am 12:08 AM

PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7

See all articles