In today's Internet age, data is at the heart of Internet applications. For developers, getting and processing data is an important part of their daily work. In this article, we will introduce how to use the powerful Jsoup library in Scala for network requests and HTML parsing, so as to realize the crawling Jingdong website data, let's explore it!
1. Why Scala and Jsoup?
Advantages of Scala
Scala is a multi-paradigm programming language with functional and object-oriented programming, but also perfectly compatible with the Java language. It has powerful type inference, higher-order functions, pattern matching, and other features that make code more concise, flexible, and easy to maintain. Since Scala integrates seamlessly with Java, it is easy to take advantage of the rich tools and libraries in the Java ecosystem.
The power of Jsoup
Jsoup is an open source Java HTML parsing library , it provides a set of simple but powerful API to easily extract the required information from the HTML document . Compared with other HTML parsing library , Jsoup has the following advantages:
- Easy to use : Jsoup provides an intuitive , easy to understand API , making it easy for developers to extract the required data from HTML documents , without the need for complex configuration and learning costs .
- Powerful selector : Jsoup supports CSS-like selector syntax , you can flexibly locate and extract elements in HTML documents , greatly simplifying the process of data extraction .
- Stable and reliable : Jsoup after a long period of development and testing , has been widely used in a variety of projects , and has been the community's continuous maintenance and updates to ensure its stability and reliability .
Crawling Jingdong Case Study
1. Code logic analysis
The purpose of this case is to demonstrate how to use Scala and Jsoup library to crawl the Jingdong website product data. It is mainly divided into the following steps:
- Parses the URL to get the HTML code of the Jingdong page;
- Solve the problem of BOE security interface jumping;
- Get the HTML element for each set of product data;
- Parses each set of product data for specific product information such as name, price, links, etc.
2. Complete code process
Below is a complete sample code that demonstrates how to use Scala and the Jsoup library to crawl the product data on the Jingdong website:
import
import ._
object JdSpider {
def main(args: Array[String]): Unit = {
val url = "/Search?keyword=cell phone"
val proxyHost = ""
val proxyPort = "5445"
val proxyUser = "16QMSOML"
val proxyPass = "280651"
val doc = (url)
.proxy(proxyHost, )
.proxyUsername(proxyUser)
.proxyPassword(proxyPass)
.ignoreHttpErrors(true)
.get()
val items = (".item")
for (item <- ) {
val name = (".name").text()
val price = (".price").text()
val links = (".link").attr("href")
val imgUrl = (".img").attr("src")
println("Trade name:" + name)
println("Price of goods:" + price)
println("Merchandise link:" + links)
println("Product Image:" + imgUrl)
println("----------")
}
}
}3. Practical tips and best practices
- Customized Data Crawling: You can customize the data you need to crawl according to your needs, such as product name, price, sales volume and so on.
- Exception Handling: In the process of network request and HTML parsing, various exceptions may occur, we need to reasonably handle these exceptions to ensure the stability of the program.
- Data Storage: The crawled data can be stored in a database or file for subsequent analysis and use.
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