How can you search Google Programmatically Java API

To search google using API you should use Google Custom Search, scraping web page is not allowed

In java you can use CustomSearch API Client Library for Java

The maven dependency is:

<dependency>
    <groupId>com.google.apis</groupId>
    <artifactId>google-api-services-customsearch</artifactId>
    <version>v1-rev57-1.23.0</version>
</dependency>

Example code searching using Google CustomSearch API Client Library

public static void main(String[] args) throws GeneralSecurityException, IOException {

    String searchQuery = "test"; //The query to search
    String cx = "002845322276752338984:vxqzfa86nqc"; //Your search engine

    //Instance Customsearch
    Customsearch cs = new Customsearch.Builder(GoogleNetHttpTransport.newTrustedTransport(), JacksonFactory.getDefaultInstance(), null) 
                   .setApplicationName("MyApplication") 
                   .setGoogleClientRequestInitializer(new CustomsearchRequestInitializer("your api key")) 
                   .build();

    //Set search parameter
    Customsearch.Cse.List list = cs.cse().list(searchQuery).setCx(cx); 

    //Execute search
    Search result = list.execute();
    if (result.getItems()!=null){
        for (Result ri : result.getItems()) {
            //Get title, link, body etc. from search
            System.out.println(ri.getTitle() + ", " + ri.getLink());
        }
    }

}

As you can see you will need to request an api key and setup an own search engine id, cx.

Note that you can search the whole web by selecting "Search entire web" on basic tab settings during setup of cx, but results will not be exactly the same as a normal browser google search.

Currently (date of answer) you get 100 api calls per day for free, then google like to share your profit.


Google TOS have been relaxed a bit in April 2014. Now it states:

"Don’t misuse our Services. For example, don’t interfere with our Services or try to access them using a method other than the interface and the instructions that we provide."

So the passage about "automated means" and scripts is gone now. It evidently still is not the desired (by google) way of accessing their services, but I think it is now formally open to interpretation of what exactly an "interface" is and whether it makes any difference as of how exactly returned HTML is processed (rendered or parsed). Anyhow, I have written a Java convenience library and it is up to you to decide whether to use it or not:

https://github.com/afedulov/google-web-search


Some facts:

  1. Google offers a public search webservice API which returns JSON: http://ajax.googleapis.com/ajax/services/search/web. Documentation here

  2. Java offers java.net.URL and java.net.URLConnection to fire and handle HTTP requests.

  3. JSON can in Java be converted to a fullworthy Javabean object using an arbitrary Java JSON API. One of the best is Google Gson.

Now do the math:

public static void main(String[] args) throws Exception {
    String google = "http://ajax.googleapis.com/ajax/services/search/web?v=1.0&q=";
    String search = "stackoverflow";
    String charset = "UTF-8";
    
    URL url = new URL(google + URLEncoder.encode(search, charset));
    Reader reader = new InputStreamReader(url.openStream(), charset);
    GoogleResults results = new Gson().fromJson(reader, GoogleResults.class);
    
    // Show title and URL of 1st result.
    System.out.println(results.getResponseData().getResults().get(0).getTitle());
    System.out.println(results.getResponseData().getResults().get(0).getUrl());
}

With this Javabean class representing the most important JSON data as returned by Google (it actually returns more data, but it's left up to you as an exercise to expand this Javabean code accordingly):

public class GoogleResults {

    private ResponseData responseData;
    public ResponseData getResponseData() { return responseData; }
    public void setResponseData(ResponseData responseData) { this.responseData = responseData; }
    public String toString() { return "ResponseData[" + responseData + "]"; }

    static class ResponseData {
        private List<Result> results;
        public List<Result> getResults() { return results; }
        public void setResults(List<Result> results) { this.results = results; }
        public String toString() { return "Results[" + results + "]"; }
    }

    static class Result {
        private String url;
        private String title;
        public String getUrl() { return url; }
        public String getTitle() { return title; }
        public void setUrl(String url) { this.url = url; }
        public void setTitle(String title) { this.title = title; }
        public String toString() { return "Result[url:" + url +",title:" + title + "]"; }
    }

}

###See also:

  • How to fire and handle HTTP requests using java.net.URLConnection
  • How to convert JSON to Java

Update since November 2010 (2 months after the above answer), the public search webservice has become deprecated (and the last day on which the service was offered was September 29, 2014). Your best bet is now querying http://www.google.com/search directly along with a honest user agent and then parse the result using a HTML parser. If you omit the user agent, then you get a 403 back. If you're lying in the user agent and simulate a web browser (e.g. Chrome or Firefox), then you get a way much larger HTML response back which is a waste of bandwidth and performance.

Here's a kickoff example using Jsoup as HTML parser:

String google = "http://www.google.com/search?q=";
String search = "stackoverflow";
String charset = "UTF-8";
String userAgent = "ExampleBot 1.0 (+http://example.com/bot)"; // Change this to your company's name and bot homepage!

Elements links = Jsoup.connect(google + URLEncoder.encode(search, charset)).userAgent(userAgent).get().select(".g>.r>a");

for (Element link : links) {
    String title = link.text();
    String url = link.absUrl("href"); // Google returns URLs in format "http://www.google.com/url?q=<url>&sa=U&ei=<someKey>".
    url = URLDecoder.decode(url.substring(url.indexOf('=') + 1, url.indexOf('&')), "UTF-8");
    
    if (!url.startsWith("http")) {
        continue; // Ads/news/etc.
    }
    
    System.out.println("Title: " + title);
    System.out.println("URL: " + url);
}

In the Terms of Service of google we can read:

5.3 You agree not to access (or attempt to access) any of the Services by any means other than through the interface that is provided by Google, unless you have been specifically allowed to do so in a separate agreement with Google. You specifically agree not to access (or attempt to access) any of the Services through any automated means (including use of scripts or web crawlers) and shall ensure that you comply with the instructions set out in any robots.txt file present on the Services.

So I guess the answer is No. More over the SOAP API is no longer available

Tags:

Java

Google Search Api

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