Recently I’ve discovered ability to search in Google from Java program in a way different from brute “crawling”.And I’ve found out two options:
Google SOAP API
With this API you can issue search requests to Google’s index of billions of web pages and receive results as structured data, access information in the Google cache, and check the spelling of words. Google SOAP Search API is implemented as a web service and all you need is just get WSDL and call remote methods through SOAP protocol. Usage of this service is limited to 1000 requests per day.
But as you can read on SOAP API site
As of December 5, 2006, we are no longer issuing new API keys for the SOAP Search API. Developers with existing SOAP Search API keys will not be affected.
So you aren’t able to get API key (I found the old one in Internet). And Google encourages you to use the AJAX Search API, which is described below.
Example of code that perform search request and show obtained results.
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| import com.google.soap.search.*;
import java.io.*;
public class SimpleGoogleDemo {
public static void main(String[] args) {
// Create a Google Search object, set our authorization key
GoogleSearch s = new GoogleSearch();
String clientKey="xxxxxxxxxxxxxxxxxxxxxxxxxxxx";
s.setKey(clientKey);
s.setQueryString("vera.org.ua");
GoogleSearchResult result = null;
// Depending on user input, do search or cache query, then print out result
try {
result = s.doSearch();
}
catch (GoogleSearchFault f) {
System.out.println("The call to the Google Web APIs failed:");
System.out.println(f.toString());
} // if we made it here, the search went through
System.out.println("Google Search Results:");
System.out.println("======================");
if (result!= null)
System.out.println(result.toString());
}
} |
To run this code you need to have googleapi.jar in your classpath. This jar file contains very useful and easy-to-use class com.google.soap.search.GoogleSearch, which does all search work.
Google AJAX API
Usage of this unlimited and you can make as many request as you want. Despite the fact that Google in this API FAQ say “The Google AJAX Search API is currently available only for websites.” ability to use it exists 
Example of code that perform search request and show obtained results.
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| import java.io.*;
import java.net.*;
public class GoogleAJAXSearchAPI {
private static String endpointURL = "http://ajax.googleapis.com/ajax/services/search/web?v=1.0&q=vera";
public static void main(String[] args) throws Exception {
URLConnection uc = new URL(endpointURL).openConnection();
HttpURLConnection connection = (HttpURLConnection) uc;
connection.setDoOutput(true);
connection.setRequestMethod("GET");
connection.connect();
String line;
InputStream inputStream = null;
try {
inputStream = connection.getInputStream();
} catch (IOException e) {
inputStream = connection.getErrorStream();
}
BufferedReader rd = new BufferedReader(new InputStreamReader(inputStream));
while ((line = rd.readLine()) != null) {
System.out.println(line);
}
}
} |
To run this code you need to can get API key here.
So, have fun
PS Look at this too - Java OO wrapper for Google AJAX API
