Reputation: 194
I've been working on making a simple program that runs through all the links in a page, and visits them, then recurses. But it seems to stop as soon as its run with the error
java.net.MalformedURLException: no protocol: /intl/en/policies/
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at me.dylan.WebCrawler.WebC.sendGetRequest(WebC.java:67)
at me.dylan.WebCrawler.WebC.<init>(WebC.java:27)
at me.dylan.WebCrawler.WebC.main(WebC.java:36)
My code:
package me.dylan.WebCrawler;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import javax.swing.text.BadLocationException;
import javax.swing.text.EditorKit;
import javax.swing.text.MutableAttributeSet;
import javax.swing.text.html.HTML;
import javax.swing.text.html.HTMLDocument;
import javax.swing.text.html.HTMLEditorKit;
public class WebC {
// FileUtil f;
int linkamount=0;
ArrayList<URL> visited = new ArrayList<URL>();
ArrayList<String> urls = new ArrayList<String>();
public WebC() {
try {
// f= new FileUtil();
sendGetRequest("http://www.google.com");
} catch (IOException e) {
e.printStackTrace();
}
catch (BadLocationException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
new WebC();
}
public void sendGetRequest(String path) throws IOException, BadLocationException, MalformedURLException {
URL url = new URL(path);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("GET");
con.setRequestProperty("Content-Language", "en-US");
BufferedReader rd = new BufferedReader(new InputStreamReader(con.getInputStream()));
EditorKit kit = new HTMLEditorKit();
HTMLDocument doc = (HTMLDocument)kit.createDefaultDocument();
doc.putProperty("IgnoreCharsetDirective", new Boolean(true));
kit.read(rd, doc, 0);
//Get all <a> tags (hyperlinks)
HTMLDocument.Iterator it = doc.getIterator(HTML.Tag.A);
while (it.isValid())
{
MutableAttributeSet mas = (MutableAttributeSet)it.getAttributes();
//get the HREF attribute value in the <a> tag
String link = (String)mas.getAttribute(HTML.Attribute.HREF);
if(link!=null && link!="") {
urls.add(link);
}
it.next();
}
for(int i=urls.size()-1;i>=0;i--) {
if(urls.get(i)!=null) {
if(/*f.searchforString(urls.get(i)) ||*/ visited.contains(new URL(urls.get(i)))) {
urls.remove(i);
continue;
} else {
System.out.println(linkamount++);
System.out.println(path);
visited.add(new URL(path));
//f.write(urls.get(i));
sendGetRequest(urls.get(i));
}
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}
I honestly have no idea how to work around this. Apparently google has a href tag that is not a valid url, how would I work around this?
Upvotes: 2
Views: 7541
Reputation: 37506
A quick fix would be to append urls.get(i)
to requestPath
before calling. That would give it a protocol and a domain to use. The only catch is that if you don't scan the current url in the loop for a protocol and domain, you may end up like this:
http://www.google.com/http://www.yahoo.com/policies
Upvotes: 1
Reputation: 2586
You must append the baseURl in the URL section. The URL object expects it in format http://abc.com/int/etc/etc.
While the form will have in the format of relative format.Easy way out is to just append the http://www.google.com before calling get in each of the HREFs you get.
Upvotes: 4