Recipe 27.4 Using a JSP to Connect with Google


Problem

You want to search Google using the Google Web APIs and a JSP.

Solution

Use the jsp:useBean standard action to get access to the GoogleBean from Example 27-2, then use this bean instance to connect with Google's web tools.

Discussion

The JSP in Example 27-4 uses the JSTL core tags to determine if the user has sent a search query along with their request. If the query request parameter is empty, then the JSP displays a form (see Figure 27-1). See Chapter 23 for details on the JSTL core tags.

If the request parameter is filled by a search query, the JSP uses the GoogleBean to search google.com and display the results. The JSP uses the jsp:useBean standard action to create an instance of the bean, which is stored in the WEB-INF/lib directory.

Example 27-4. A JSP uses a JavaBean to search google.com
  <%@ taglib uri="http://java.sun.com/jstl/core" prefix="c" %>  <html> <head><title>Search Google from a JSP</title></head> <body>  <c:choose>    <c:when test="${empty param.query}">  <h2>Please enter your search terms...</h2>  <%-- Display the HTML form... --%>  <form method="POST" action ='<c:out value=    "${pageContext.request.contextPath}" />/google.jsp'>        <table border="0">    <tr><td valign="top">        Search terms: </td>  <td valign="top">        <input type="text" name="query" size="15">        </td></tr>    <tr><td valign="top">        Restrict to Google sub-site... </td>  <td valign="top">        <select name="restrict">    <option selected>none</option><option>unclesam</option>    <option>linux</option>    <option>mac</option><option>bsd</option></select>        </td></tr>    <tr><td valign="top">        <input type="submit" value="Submit Info"></td></tr>        </table></form>  <%-- End of the HTML form... --%>         </c:when>         <c:otherwise>          <%-- Create an instance of the GoogleBean --%>     <jsp:useBean id="gBean" class="com.jspservletcookbook.GoogleBean" />  <h2>Here are your search results</h2>  <%-- Set the query, restrict, and lineSep properties of the GoogleBean --%>         <jsp:setProperty name="gBean" property="query" param="query"/>         <jsp:setProperty name="gBean" property="restrict" param="restrict"/>         <jsp:setProperty name="gBean" property="lineSep" value="<br /><br />"/>                  <%-- Now display any results of the search --%>         <jsp:getProperty name="gBean" property="searchResults" />                  </c:otherwise> </c:choose>  </body> </html> 

The JSP uses the jsp:setProperty standard action to the bean instance's query , restrict , and lineSep properties. The query represents the search terms; restrict can have values of mac, linux, bsd, or unclesam, representing various Google sub-sites, and the lineSep property determines the line-separation characters to use when formatting the results (<br/> in this example).

Finally, the code uses jsp:getProperty to effectively call the GoogleBean's getSearchResults( ) method, which sends a SOAP message to Google and formats the response.

See Also

The home for Google Web Service: http://www.google.com/apis/; the Google web APIs SDK: http://www.google.com/apis/download.html; Recipe 27.1 on setting up your programming environment for use with the Google Web APIs; Recipe 27.3 on using a servlet to connect with Google web services.



Java Servlet & JSP Cookbook
Java Servlet & JSP Cookbook
ISBN: 0596005725
EAN: 2147483647
Year: 2004
Pages: 326

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