Extract https urls using jsoup - java

I have the following code that extracts urls from a given page using jsoup.
import org.jsoup.Jsoup;
import org.jsoup.helper.Validate;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
import java.io.IOException;
/**
* Example program to list links from a URL.
*/
public class ListLinks {
public static void main(String[] args) throws IOException {
String url = "http://shopping.yahoo.com";
print("Fetching %s...", url);
Document doc = Jsoup.connect(url).get();
Elements links = doc.getElementsByTag("a");
print("\nLinks: (%d)", links.size());
for (Element link : links) {
print(" * a: <%s> (%s)", link.absUrl("href") /*link.attr("href")*/, trim(link.text(), 35));
}
}
private static void print(String msg, Object... args) {
System.out.println(String.format(msg, args));
}
private static String trim(String s, int width) {
if (s.length() > width)
return s.substring(0, width-1) + ".";
else
return s;
}
}
What I'm trying to do, is to build a crawler that extracts only https site. I give the crawler a seed link to start with, then it should extracts all https site, then take each of the extracted link and do the same with them until reaching a certain number of collected urls.
My questions: The above code can extract all links in a given page. I need to extract links that starts with https:// only, what do I need to do in order to achieve this ?

You can use selectors of jsoup. They are pretty powerful.
doc.select("a[href*=https]");//(This is the one you are looking for)selects if value of href contatins https
doc.select("a[href^=www]");//selects if value of href starts with www
doc.select("a[href$=.com]");//selects if value of href ends with .com.
etc.. Experiment with them, you will find out the correct one.

Related

Create a String variable from a URL using JSoup and Regex in Java?

So I am trying to make a program that retrieves the IFrame tag from a website, opens the link and downloads the video. Currently, it retrieves the IFrame tag, but I can't figure out how to ignore the actual tags. I am pretty sure I can use the .split() feature, but I don't know how to create a regex code to only pull the data from inside of the quotes. I also tried using JSoup's .html, but it just printed a blank statement. Here is what I have (It mostly split correctly, except in the URL there is "id=..." which causes it to split again):
package com.trentmenard;
import java.io.IOException;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
public class Main {
public static void main(String[] args) {
Document website;
try{
website = Jsoup.connect("https://swordartonlineepisode.com/sword-art-online-season-3-episode-1-english-dubbed-watch-online/").get();
System.out.println("Website Found! Title: " + website.title());
Element videoLink = website.select("iframe").first();
System.out.println("Found Video Link: " + videoLink);
videoLink.removeAttr("width");
videoLink.removeAttr("height");
videoLink.removeAttr("scrolling");
videoLink.removeAttr("allowfullscreen");
System.out.println("Modified: " + videoLink);
String link = videoLink.toString();
String[] stringArray = link.split("=");
for(String a : stringArray){
System.out.println(a);
}
}
catch (IOException e) {
e.printStackTrace();
}
}
}
Output: https://i.stack.imgur.com/ZXTiV.png
Thanks in advance!

Using Jsoup to parse search descriptions in SERPS (Google Results)

I keep running into a problem whenever I try to scrape off searches from Google Search results. I am using Jsoup to pull out the HTML code, but I am unable to pull out the information from the webpage that I need. I am aiming to reach the descriptions of the information under the titles. Here is my code:
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.Proxy;
public class internetSearch {
public void retrieveFileInfo(String pulling) {
Document doc;
try {
String proxyAdress = "1.2.3.4";
int proxyPort = 1234;
Proxy proxy = new Proxy(Proxy.Type.HTTP, InetSocketAddress.createUnresolved(proxyAdress, proxyPort));
doc = Jsoup
.connect(pulling)
.userAgent("Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)")
.header("Content-Language", "en-US")
.timeout(0)
.get();
System.out.println(doc.toString());
Elements links = doc.select("div[class=g]");
for (Element link : links) {
Elements titles = link.select("h3[class=r]");
String title = titles.text();
Elements bodies = link.select("span[class=st]");
String body = bodies.text();
System.out.println("Title: " + title);
System.out.println("Body: " + body + "\n");
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
I've used many sources across the web in order to get my code. In the past, I used Selenium as well, but to no avail.
I continuously search through my outcome in order to find the class ".st" which it is under (in h3, span, .st), and I do not reach a conclusion.
Is it just simply Google jumbling up the code or am I missing something vital?
Here is a solution with estivate (which is a Java DOM Parser with Annotations compatible with JSoup)
Document doc = // here your JSoup document grabbing
EstivateMapper2 mapper = new EstivateMapper2()
List<GoogleResult> results = mapper.mapToList(doc, GoogleResult .class);
with the defintion of GoogleResult as follow :
#Select("div.g")
public class GoogleResult {
#Text(select = "h3.r")
public String title;
#Text(select = "div.s cite")
public String link;
#Text(select = "span.st")
public String body;
}

Why "http://www.stackoverflow.com" is not getting parsed but "http://www.javatpoint.com/java-tutorial" is getting parsed

I am trying to learn the basic methods of jsoup.I tried to get all the hyperlinks
of a particular web page.But i used stackoverflow link then,i am unable to get all the hyperlinks on that page ,but on the other side when i changed it to
javatpoint it's working.
Can someone explain Why??
Here is the code.
import java.io.IOException;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
import org.jsoup.*;
import org.jsoup.nodes.*;
import java.io.*;
import org.jsoup.nodes.Document;
class Repo {
// String html;
public static void main(String s[]) throws IOException {
try {
Document doc = Jsoup.connect("http://www.javatpoint.com/java-tutorial").get();
// Document doc=Jsoup.connect("http://www.stackoverflow.com").get();
System.out.println("doc");
// Elements link=(Elements)doc.select("span[class]");
// Elements link = doc.select("span").first();
// Elements link = (Elements)doc.select("span");
Elements link = (Elements) doc.select("a[href]");
for (Element el : link) {
// System.out.print("-");
// System.out.println(el.attr("class"));
String str = el.attr("href");
System.out.println(str);
}
} catch (Exception e) {
}
}
}
Many websites require valid http requests to carry certain headers. A prominent example is the userAgent header. SO for example will work with this:
Document doc = Jsoup
.connect("http://www.stackoverflow.com")
.userAgent("Mozilla/5.0")
.get();
Side note:
You should never try catch exceptions and then silently ignore the possible fail case. At least do some logging there - otherwise your programs will be very hard to debug.

get links in a web site

how can i get links in a web page without loading it? (basically what i want is this. a user enters a URL and i want to load all the available links inside that URL.) can you please tell me a way to achieve this
Here is example Java code, specifically:
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import javax.swing.text.MutableAttributeSet;
import javax.swing.text.html.HTML;
import javax.swing.text.html.HTMLEditorKit;
import javax.swing.text.html.parser.ParserDelegator;
public class Main {
public static void main(String args[]) throws Exception {
URL url = new URL(args[0]);
Reader reader = new InputStreamReader((InputStream) url.getContent());
System.out.println("<HTML><HEAD><TITLE>Links for " + args[0] + "</TITLE>");
System.out.println("<BASE HREF=\"" + args[0] + "\"></HEAD>");
System.out.println("<BODY>");
new ParserDelegator().parse(reader, new LinkPage(), false);
System.out.println("</BODY></HTML>");
}
}
class LinkPage extends HTMLEditorKit.ParserCallback {
public void handleStartTag(HTML.Tag t, MutableAttributeSet a, int pos) {
if (t == HTML.Tag.A) {
System.out.println("<A HREF=\"" + a.getAttribute(HTML.Attribute.HREF) + "\">"
+ a.getAttribute(HTML.Attribute.HREF) + "</A><BR>");
}
}
}
You'll have to load the page on your server and then find the links, preferably by loading up the document in an HTML/XML parser and traversing that DOM. The server could then send the links back to the client.
You can't do it on the client because the browser won't let your Javascript code look at the contents of the page from a different domain.
If you want the content of a page you'll have to load it. But what you can do is loading it in memory and parse it to get all the <a> tags and their content.
You'll be able to parse this XML with tools like JDom or Sax if you're working with java (as your tag says) or with simple DOM tools with javascript.
Resources :
Parse XML with javascript
On the same topic :
get all the href attributes of a web site (javascript)
Just open an URLConnection, gets the page and parse it.
public void extract_link(String site)
{
try {
List<String> links = extractLinks(site);
for (String link : links) {
System.out.println(link);
}
} catch (Exception e) {
System.out.println(e);
}
}
This is a simple function to view all links in a page.
If you want to view link in the inner links , just call it recursively(but make sure you give a limit according to your need).

Full Link Extraction using java

My goal is to always get the same string (which is the URI in my case) while reading the href property from a link. Example:
Suppose think that a html file it have somany links like
a href="index.html"> but base domain is http://www.domainname.com/index.html
a href="../index.html"> but base domain is http://www.domainname.com/dit/index.html
how can i get all the link correctly means the full link including domain name?
how can i do that in java?
the input is HTML,that is,from a bunch of HTML code it need to extract correct link
You can do this using a fullworthy HTML parser like Jsoup. There's a Node#absUrl() which does exactly what you want.
package com.stackoverflow.q3394298;
import java.net.URL;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
public class Test {
public static void main(String... args) throws Exception {
URL url = new URL("https://stackoverflow.com/questions/3394298/");
Document document = Jsoup.connect(url).get();
Element link = document.select("a.question-hyperlink").first();
System.out.println(link.attr("href"));
System.out.println(link.absUrl("href"));
}
}
which prints (correctly) the following for the title link of your current question:
/questions/3394298/full-link-extraction-using-java
https://stackoverflow.com/questions/3394298/full-link-extraction-using-java
Jsoup may have more other (undiscovered) advantages for your purpose as well.
Related questions:
What are the pros and cons of the leading HTML parsers in Java?
Update: if you want to select all links in the document, then do as follows:
Elements links = document.select("a");
for (Element link : links) {
System.out.println(link.attr("href"));
System.out.println(link.absUrl("href"));
}
Use the URL object:
URL url = new URL(URL context, String spec)
Here's an example:
import java.net.*;
public class Test {
public static void main(String[] args) throws Exception {
URL base = new URL("http://www.java.com/dit/index.html");
URL url = new URL(base, "../hello.html");
System.out.println(base);
System.out.println(url);
}
}
It will print:
http://www.java.com/dit/index.html
http://www.java.com/hello.html

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