Java code for using google custom search API

Question

Can anyone please share some java codes for getting started with google search api\'s.I searched on Internet but not found any proper documentation or good sample codes.The

Answer 1

Well, I think that there is nothing special in the sense that you can use a Java RESTFUL client.

I tried the Custom API using that Java code and basing on the Google documentation :

public static void main(String[] args) throws IOException {
        URL url = new URL(
                "https://www.googleapis.com/customsearch/v1?key=YOUR-KEY&cx=013036536707430787589:_pqjad5hr1a&q=flowers&alt=json");
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("GET");
        conn.setRequestProperty("Accept", "application/json");
        BufferedReader br = new BufferedReader(new InputStreamReader(
                (conn.getInputStream())));

        String output;
        System.out.println("Output from Server .... \n");
        while ((output = br.readLine()) != null) {
            System.out.println(output);
        }

        conn.disconnect();
    }

You have to replace "YOUR-KEY" with a one found on the Google APIs Console.

Answer 2

For anyone who would need working example of Custom search API using Google library, you can use this method:

public static List<Result> search(String keyword){
    Customsearch customsearch= null;


    try {
        customsearch = new Customsearch(new NetHttpTransport(),new JacksonFactory(), new HttpRequestInitializer() {
            public void initialize(HttpRequest httpRequest) {
                try {
                    // set connect and read timeouts
                    httpRequest.setConnectTimeout(HTTP_REQUEST_TIMEOUT);
                    httpRequest.setReadTimeout(HTTP_REQUEST_TIMEOUT);

                } catch (Exception ex) {
                    ex.printStackTrace();
                }
            }
        });
    } catch (Exception e) {
        e.printStackTrace();
    }
    List<Result> resultList=null;
    try {
        Customsearch.Cse.List list=customsearch.cse().list(keyword);
        list.setKey(GOOGLE_API_KEY);
        list.setCx(SEARCH_ENGINE_ID);
        Search results=list.execute();
        resultList=results.getItems();
    }
    catch (  Exception e) {
        e.printStackTrace();
    }
    return resultList;
}

This method returns List of Result objects, so you can iterate through it

    List<Result> results = new ArrayList<>();

    try {
        results = search(QUERY);
    } catch (Exception e) {
        e.printStackTrace();
    }
    for(Result result : results){
        System.out.println(result.getDisplayLink());
        System.out.println(result.getTitle());
        // all attributes:
        System.out.println(result.toString());
    }

As you have noticed, you have to define your custom GOOGLE_API_KEY, SEARCH_ENGINE_ID, QUERY and HTTP_REQUEST_TIMEOUT, ie

private static final int HTTP_REQUEST_TIMEOUT = 3 * 600000;

I use gradle dependencies:

dependencies {
compile 'com.google.apis:google-api-services-customsearch:v1-rev57-1.23.0'
}

Answer 3

I have changed the while loop in the code provided by @Zakaria above. It might not be a proper way of working it out but it gives you the result links of google search. You just need to parse the output. See here,

public static void main(String[] args) throws Exception {

    String key="YOUR KEY";
    String qry="Android";
    URL url = new URL(
            "https://www.googleapis.com/customsearch/v1?key="+key+ "&cx=013036536707430787589:_pqjad5hr1a&q="+ qry + "&alt=json");
    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
    conn.setRequestMethod("GET");
    conn.setRequestProperty("Accept", "application/json");
    BufferedReader br = new BufferedReader(new InputStreamReader(
            (conn.getInputStream())));

    String output;
    System.out.println("Output from Server .... \n");
    while ((output = br.readLine()) != null) {

        if(output.contains("\"link\": \"")){                
            String link=output.substring(output.indexOf("\"link\": \"")+("\"link\": \"").length(), output.indexOf("\","));
            System.out.println(link);       //Will print the google search links
        }     
    }
    conn.disconnect();                              
}

Hope it works for you too.