Seeking a web spider, written in Java, able to crawl web content.

Answer 1

Web crawlers usually referred to an automated program that crawled information from the Internet. Java is a widely used programming language that can be used to write web spiders. Below is a simple example of a web crawling program that uses the DOM and the browser to retrieve web content:

```java
import javaio*;
import javanet*;
import javautil*;

public class Web Crawler {
public static void main(String[] args) throws Exception {
//Set the crawl page's Url
String url = https://wwwexamplecom;

//Create an object
HTTPClient client = new HTTPClient();

//Create an object for the response.

get(new BufferedReader(new InputStreamReader(responsegetEntity()getContents())))
end();

//Parse the document
HTMLDocument doc = (HTMLDocument) HTMLParserparse(responsegetEntity()getContents());

//Get web content
String content = docgetBody()toString();

//Print webpage content
Systemoutprintln(content);
}
}
```

This example uses the java-based HttpClient and HttmParser libraries to send an Http request and to analyze the HttmParser document. In the request, we use the `connect()` method to receive the web page content as an IP response. Then, we use the `get()` method to read the document and use the `HMTLParser` class to analyze it into a string. Finally, we use the getBody() method to get the entire content of the document and print it to the console using the toString() method.

It should be noted that this is just a simple example. The actual web crawling should be more complicated, including dealing with anti-crawling measures, dealing with browser tags and attributes, handling exceptions, and so on. At the same time, the use of web crawlers must abide by relevant laws, regulations and ethics. They must not be used for illegal purposes.