Tuesday, December 05, 2006

Data Access with Spring and Struts: Part 1

The struts pagination post contained an example of using Hibernate for data access too. In this post, I use the same example to implement the same pagination example using Spring. In this part we will see how to get a struts application ready for spring, the next part describes how to implement data access in spring. Follow these steps to run the example.
  1. Start with the struts-blank application
  2. Create the search.jsp file
    <%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
    <%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean"%>
    <%@ taglib uri="http://struts.apache.org/tags-html" prefix="html"%>
    <%@ taglib uri="http://struts.apache.org/tags-logic" prefix="logic"%>
    <%@ taglib uri="http://displaytag.sf.net" prefix="display"%>
    <%@ page import="beans.Employee,business.Sorter,java.util.List,org.displaytag.tags.TableTagParameters,org.displaytag.util.ParamEncoder"%>
    <html:html>
    <head>
    <title>Search page</title>
    <link rel="stylesheet" type="text/css"
    href="/StrutsPaging/css/screen.css" />
    </head>
    <body bgcolor="white">
    <html:form action="/search.do">
    <table>
     <tr>
       <td>Minimum Salary:</td>
       <td><html:text property="minSalary"></html:text></td>
     </tr>
     <tr>
       <td colspan="2"><html:submit property="submit" /></td>
     </tr>
    </table>
    </html:form>
    <logic:notEqual name="empList" value="null">
    <jsp:scriptlet>
     if (session.getAttribute("empList") != null) {
       String sortBy = request.getParameter((new ParamEncoder("empTable")).encodeParameterName(TableTagParameters.PARAMETER_SORT));
       Sorter.sort((List) session.getAttribute("empList"), sortBy);
     }
    </jsp:scriptlet>

    <display:table name="sessionScope.empList" pagesize="4" id="empTable" sort="external" defaultsort="1" defaultorder="ascending" requestURI="">
     <display:column property="empId" title="ID" sortable="true" sortName="empId" headerClass="sortable" />
     <display:column property="empName" title="Name" sortName="empName" sortable="true" headerClass="sortable" />
     <display:column property="empJob" title="Job" sortable="true" sortName="empJob" headerClass="sortable" />
     <display:column property="empSal" title="Salary" sortable="true" headerClass="sortable" sortName="empSal" />
    </display:table>
    </logic:notEqual>
    </body>
    </html:html>
    pages/search.jsp
  3. Create the Action class: 
    public class SearchAction extends Action {
    private BusinessInterface businessInterface;
    public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse httpservletresponse) throws Exception {
     if (form == null) {
       return mapping.findForward("success");
     }
     try {
       SearchForm searchForm = (SearchForm) form;
       if (searchForm.getMinSalary() == null || searchForm.getMinSalary().equals("")) {
         return mapping.findForward("success");
       }
       long minSal = Long.parseLong(searchForm.getMinSalary());
       System.out.println("Business Interface: " + businessInterface);
       List data = businessInterface.getData(minSal);
       System.out.println("Data : " + data);
       request.getSession().setAttribute("empList", data);

     } catch (Exception e) {
       e.printStackTrace();
     }
     return mapping.findForward("success");
    }

      public void setBusinessInterface(BusinessInterface bi) {
        businessInterface = bi;
      }
    }
    SearchAction.java

    Note that the action class has a property businessInterface. This property will be set by spring when loading the action class.
  4. Define the form and action beans in struts-config.xml
    <form-beans>
    <form-bean name="searchForm" type="forms.SearchForm" />
    </form-beans>
    <action-mappings>
    <action path="/Welcome" forward="/pages/Welcome.jsp" />
    <action name="searchForm" path="/search" scope="session" type="org.springframework.web.struts.DelegatingActionProxy">
     <forward name="success" path="/pages/search.jsp"></forward>
    </action>
    </action-mappings>
    Note that, in the action-mapping, the action type is defined as "org.springframework.web.struts.DelegatingActionProxy". This will ensure that Spring will take care of handling struts actions.

  5. Integrate Struts And Spring: The final step of integration is to add a spring plugin to struts-config.xml. The plugin defines the location of the spring bean-factory definitions.
    <plug-in className="org.springframework.web.struts.ContextLoaderPlugIn">
    <set-property property="contextConfigLocation"
     value="/WEB-INF/applicationContext.xml"/>
    </plug-in>
    This is one way of integrating struts and spring, for other ways of integration, refer to : Get a better handle on Struts actions, with Spring
Continue to part 2 of "Data access with spring and struts".
Posted by at
Labels: , , ,

4 comments:

  1. AnonymousFriday, January 26, 2007 at 1:03:00 PM EST

    do you have any idea of integrating struts with spring 2... i mean is theare any proxy class for Spring2. The example you have given is for Spring 1.x

    ReplyDelete
  2. abhiFriday, January 26, 2007 at 1:13:00 PM EST

    This example was implemented on Spring 2.0.1.

    ReplyDelete
  3. JavierMonday, April 23, 2007 at 10:02:00 AM EDT

    Hi, Im having some problems while trying to use Spring AOP with Struts Actions, and I wonder if you could help me?

    Im using spring 2.0.4, and struts 1.3, I dont know if that makes any difference?

    So my struts-config is something like this:
    ....
    < action-mappings>
    < action path="/prueba"
    type="org.springframework.web.struts.DelegatingAct ionProxy"
    scope="request" validate="false" parameter="cmd">
    < /action>
    < /action-mappings>

    < plug-in className="org.springframework.web.struts.ContextL oaderPlugIn">
    < set-property property="contextConfigLocation"
    value="WEB-INF/classes/applicationContext.xml"/>
    < /plug-in>
    ..

    And my bean definition is:

    ....
    < bean name="/prueba" scope="prototype" autowire="byName"
    class="prueba.integracion.PruebaAction" />

    < aop:aspectj-autoproxy proxy-target-class="true" />
    ...

    The error Im getting is org.springframework.beans.factory.BeanNotOfRequire dTypeException, Bean named '/prueba' must be of type [org.apache.struts.action.Action], but was actually of type [$Proxy6]

    Im a bit stuck with this, so Id appreciatte any help.

    Thanks

    ReplyDelete
  4. AnonymousFriday, May 16, 2008 at 9:02:00 AM EDT

    Try in struts instead this:

    &gt action path="/prueba"
    type="org.springframework.web.struts.DelegatingAct ionProxy"
    scope="request" validate="false" parameter="cmd"&lt


    something like this(without DelegatingAct ionProxy):
    &gtaction path="/edit" name="inputForm"
    type="example.action.ViewAction" validate="false" scope="request"
    parameter="op"&lt
    &gtforward name="list" path="/jsp/index.jsp" /&lt
    &ltforward name="add" path="/jsp/input.jsp" /&gt
    &lt/action&gt

    and add:
    &ltcontroller&gt
    &ltset-property property="processorClass"
    value="org.springframework.web.struts.DelegatingRequestProcessor" /&gt
    &lt/controller&gt

    ReplyDelete

Subscribe to: Post Comments (Atom)

Popular Posts