Backend Development
PHP Tutorial
How to build a real-time web crawler with Elasticsearch and PHP
How to build a real-time web crawler with Elasticsearch and PHP
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!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1378
52
PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian
Dec 24, 2024 pm 04:42 PM
PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati
How To Set Up Visual Studio Code (VS Code) for PHP Development
Dec 20, 2024 am 11:31 AM
Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c
How do you parse and process HTML/XML in PHP?
Feb 07, 2025 am 11:57 AM
This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an
7 PHP Functions I Regret I Didn't Know Before
Nov 13, 2024 am 09:42 AM
If you are an experienced PHP developer, you might have the feeling that you’ve been there and done that already.You have developed a significant number of applications, debugged millions of lines of code, and tweaked a bunch of scripts to achieve op
Explain JSON Web Tokens (JWT) and their use case in PHP APIs.
Apr 05, 2025 am 12:04 AM
JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,
PHP Program to Count Vowels in a String
Feb 07, 2025 pm 12:12 PM
A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total
Explain late static binding in PHP (static::).
Apr 03, 2025 am 12:04 AM
Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.
What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases?
Apr 03, 2025 am 12:03 AM
What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.
