Google Hacks

Hack 56 Programming the Google Web API with Java

Programming the Google Web API in Java is a snap, thanks to all the functionality packed into the Google Web API Developer's Kit.

Thanks to the Java Archive (JAR) file included in the Google Web API Developer's Kit [Section 5.4], programming to the Google API in Java couldn't be simpler. The googleapi.jar archive includes com.google.soap.search, a nice clean wrapper around the underlying Google SOAP, along with the Apache Software Foundation's open source Crimson (http://xml.apache.org/crimson) XML parser and Apache SOAP (http://xml.apache.org/soap/) stack, among others.

You'll need a copy of the Java 2 Platform, Standard Edition (J2SE, http://java.sun.com/downloads/) to compile and run this hack.

56.1 The Code

// Googly.java
// Bring in the Google SOAP wrapper
import com.google.soap.search.*;
import java.io.*;
public class Googly {
  // Your Google API developer's key
  private static String googleKey = "insert key here"; 
  public static void main(String[] args) {
    // Make sure there's a Google query on the command-line
    if (args.length != 1) {
      System.err.println("Usage: java [-classpath classpath] Googly <query>");
      System.exit(1);
    }
    // Create a new GoogleSearch object
    GoogleSearch s = new GoogleSearch(  );
    try {
    
      s.setKey(googleKey);
      s.setQueryString(args[0]); // Google query from the command-line
      s.setMaxResults(10);
      // Query Google
      GoogleSearchResult r = s.doSearch(  );
      // Gather the results
      GoogleSearchResultElement[] re = r.getResultElements(  );
      
      // Output
      for ( int i = 0; i < re.length; i++ ) {
     System.out.println(re[i].getTitle(  ));
     System.out.println(re[i].getURL(  ));
     System.out.println(re[i].getSnippet(  ) + "\n");
      }
    
    // Anything go wrong?
    } catch (GoogleSearchFault f) {
      System.out.println("GoogleSearchFault: " + f.toString(  ));
    }
  }
  
}

Be sure to drop in your own Google developer's key Section 5.5 (e.g., 12BuCK13mY5h0E/34KN0cK@ttH3Do0R) in place of "insert key here":

// Your Google API developer's key
private static String googleKey = "12BuCK13mY5h0E/34KN0cK@ttH3Do0R";

56.2 Compiling the Code

To successfully compile the Googly application, you'll need that googleapi.jar archive. I chose to keep it in the same directory as as my Googly.java source file; if you've put it elsewhere, adjust the path after -classpath accordingly.

% javac -classpath googleapi.jar Googly.java

This should leave you with a brand new Googly.class file, ready to run.

56.3 Running the Hack

Run Googly on the command line, passing it your Google query, like so:

% java -classpath .:googleapi.jar Googly "query words"

56.4 The Results

% java -classpath .:googleapi.jar Googly "Learning Java"
oreilly.com -- Online Catalog: Learning Java  
http://www.oreilly.com/catalog/learnjava/
For programmers either just migrating to Java or already working 
steadily in the forefront of Java development, Learning Java gives 
a clear, systematic   ...    
oreilly.com -- Online Catalog:   Learning     Java  , 2nd Edition
http://www.oreilly.com/catalog/learnjava2/
This new edition of Learning Java has been expanded and updated for
Java 2 Standard Edition SDK 1.4. It comprehensively addresses ...    
... 
Java Programming...From the Grounds Up / Web Developer
http://www.webdeveloper.com/java/java_programming_grounds_up.html
... WebDeveloper.com. Java Programming... From the Grounds Up. by 
Mark C. Reynolds ... Java Classes and Methods. Java utilizes the 
basic object technology found in C++. ...