Combination of Struts 1 and Web service in a Web application

Objective
We will learn how to create a Web application using Struts 1 and Web service. A case study will be illustrated as follow:
- a Web server running on Tomcat server.
- a Web page enabling user to enter two numbers and click submit to the server
- the server receives two numbers, then calls a Web service to calculate the sum of the two numbers. And then displays the results in another page.


Config Tomcat server for a Web service
 You could see in the topic: service-oriented programming with web service
- Step 1: Download Tomcat server from Apache site: http://tomcat.apache.org/download-70.cgi (version 6.0 and higher)
- Step 2: Download  web service (AXIS) library of Apache: http://axis.apache.org/axis/
- Step 3: unzip the axis folder, copy axis folder into Tomcat\webapps. And then copy xerces.jar from Tomcat\common\lib into Tomcat\webapps\axis\WEB-INF\lib



 - Step 4: setup your environment variables:
JAVA_HOME = absolute path to your java root directory
AXIS_HOME = absolute path to your unzipped axis folder
CATALINA_HOME = absolute path to your Tomcat folder
DEPLOY_HOME = {CATALINA_HOME}\webapps\axis\WEB-INF\lib


Create a Web service
- Step 5: Go to the directory: \Tomcat\webapps\axis, create a file named Calculators.jws with this content:

public class Calculators{
    public String Add(double x, double y){
        return (x+y)+"";
    }
   
    public String Sub(double x, double y){
        return (x-y)+"";
    }
   
    public String Mul(double x, double y){
        return (x*y)+"";
    }
   
    public String Div(double x, double y){
        return (x/y)+"";
    }
}

- Step 6: Verifying your Web service by running Tomcat server (run the file Tomcat\bin\startup.bat), then running your web browser and typing the URL into address bar:
http://localhost:8080/axis/Calculators.jws?wsdl
If this content appears, your Web service is well created!




Config and development a Web application using Struts 1 framework and Web service
- Step 1: Go to the Tomcat/webapps folder, create a web folder (strutCalculator) with a WEB-INF sub folder. In which, download the struts 1 lib into WEB-INF/lib folder:
link to download Struts 1 lib:http://mirrors.digipower.vn/apache//struts/library/struts-1.3.10-lib.zip



- Step 2: Go to the WEB-INF/src folder, create a Java project with two packages: control, entity. And then code them as:

entity.Calculator.java
package entity;
import javax.servlet.http.HttpServletRequest;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;

public class Calculator extends org.apache.struts.action.ActionForm{
    private String firstnumber;
    private String secondnumber;
    private String result;
   
    public Calculator(){
        super();
    }
   
    public Calculator(String a, String b){
        super();
        firstnumber = a;
        secondnumber = b;
    }

    public String getFirstnumber() {
        return firstnumber;
    }

    public void setFirstnumber(String firstnumber) {
        this.firstnumber = firstnumber;
    }

    public String getSecondnumber() {
        return secondnumber;
    }

    public void setSecondnumber(String secondnumber) {
        this.secondnumber = secondnumber;
    }

    public String getResult() {
        return result;
    }

    public void setResult(String result) {
        this.result = result;
    }
   
    public ActionErrors validate(ActionMapping mapping, HttpServletRequest request) {
        ActionErrors errors = new ActionErrors();
        if (firstnumber == null || firstnumber.length() < 1) {
            errors.add("firstnumber", new ActionMessage("error.firstnumber.required"));
        }else {
            try{
                Double.parseDouble(firstnumber);
            }catch(Exception e){
                errors.add("firstnumber", new ActionMessage("error.firstnumber.double"));
            }
        }
        if (secondnumber == null || secondnumber.length() < 1) {
            errors.add("secondnumber", new ActionMessage("error.secondnumber.required"));
        }else {
            try{
                Double.parseDouble(secondnumber);
            }catch(Exception e){
                errors.add("secondnumber", new ActionMessage("error.secondnumber.double"));
            }
        }
        return errors;
    }
}



control.CalculatorCtr.java
package control;
import org.apache.axis.client.Service;
import org.apache.axis.client.Call;
import org.apache.axis.encoding.XMLType;
import javax.xml.rpc.ParameterMode;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionForward;

public class CalculatorCtr extends org.apache.struts.action.Action{
    private final static String RESULT = "result";
   
    public entity.Calculator calculate(String methodName, entity.Calculator cal){
        String endpointURL="http://localhost:8080/axis/Calculator.jws";
        Service service=new Service();
                try{
                    Call call=(Call)service.createCall();
                    call.setTargetEndpointAddress(new java.net.URL(endpointURL));
                    call.setOperationName(methodName);
                    call.addParameter("a", XMLType.XSD_DOUBLE, ParameterMode.PARAM_MODE_IN);
                    call.addParameter("b", XMLType.XSD_DOUBLE, ParameterMode.PARAM_MODE_IN);
                    String result=(String)call.invoke(new Object[]{Double.parseDouble(cal.getFirstnumber()),Double.parseDouble(cal.getSecondnumber())});
                    cal.setResult(result);
                }catch(Exception ex){
                    System.out.println("Error: "+ex);
                }
         return cal;      
    }
   
    public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        entity.Calculator calculator = (entity.Calculator) form;
        form = calculate("Add", calculator);
        return mapping.findForward(RESULT);       
    }
}


After compiling these  packages, copy the .class files (including their packages) into the WEB-INF/classes folder.

- Step 3: Return to the Web root directory, create three files .jsp as follow:




add.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Web service: Add</title>
    </head>
    <body>
        <div style="color:red">
            <html:errors />
        </div>
        <html:form action="/add" >
            First number : <html:text name="Calculator" property="firstnumber" /> <br>
            Second number  : <html:text name="Calculator" property="secondnumber" /> <br>
            <html:submit value="Add" />
        </html:form>
    </body>
</html>

Note that the tags in red are Struts 1 tags, refer from the first line in red.

doAdd.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Web service: Add result</title>
    </head>
    <body>
        The sum of <bean:write name="Calculator" property="firstnumber"></bean:write>
        and <bean:write name="Calculator" property="secondnumber"></bean:write>
        is <bean:write name="Calculator" property="result"></bean:write>
    </body>
</html>

- Step 4: Go to the WEB-INF folder, copy all .tld and .xml file from Struts 1 lib into this directory as follow:



- Step 5: Edite the file web.xml and struts-config.xml as follow:

web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <servlet>
        <servlet-name>action</servlet-name>
        <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
        <init-param>
            <param-name>config</param-name>
            <param-value>/WEB-INF/struts-config.xml</param-value>
        </init-param>
        <init-param>
            <param-name>debug</param-name>
            <param-value>2</param-value>
        </init-param>
        <init-param>
            <param-name>detail</param-name>
            <param-value>2</param-value>
        </init-param>
        <load-on-startup>2</load-on-startup>
        </servlet>
    <servlet-mapping>
        <servlet-name>action</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>30</session-timeout>
    </session-config>
    <welcome-file-list>
        <welcome-file>add.jsp</welcome-file>
        </welcome-file-list>
    <jsp-config>
        <taglib>
            <taglib-uri>/WEB-INF/struts-bean.tld</taglib-uri>
            <taglib-location>/WEB-INF/struts-bean.tld</taglib-location>
        </taglib>
        <taglib>
            <taglib-uri>/WEB-INF/struts-html.tld</taglib-uri>
            <taglib-location>/WEB-INF/struts-html.tld</taglib-location>
        </taglib>
        <taglib>
            <taglib-uri>/WEB-INF/struts-logic.tld</taglib-uri>
            <taglib-location>/WEB-INF/struts-logic.tld</taglib-location>
        </taglib>
        <taglib>
            <taglib-uri>/WEB-INF/struts-nested.tld</taglib-uri>
            <taglib-location>/WEB-INF/struts-nested.tld</taglib-location>
        </taglib>
        <taglib>
            <taglib-uri>/WEB-INF/struts-tiles.tld</taglib-uri>
            <taglib-location>/WEB-INF/struts-tiles.tld</taglib-location>
        </taglib>
        </jsp-config>
    </web-app>

Note that all texts in red are the content you need to modify to be appropriated to your Web application.

struts-config.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts-config PUBLIC
          "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN"
          "http://jakarta.apache.org/struts/dtds/struts-config_1_2.dtd">

<struts-config>
    <form-beans>
        <form-bean name="Caculator" type="entity.Caculator"/>   
    </form-beans>
   
    <global-exceptions>   
    </global-exceptions>

    <global-forwards>
        <forward name="welcome"  path="/Welcome.do"/>
    </global-forwards>

    <action-mappings>
        <action input="/add.jsp" name="Caculator" path="/add" scope="session" type="control.CalculatorCtr">
            <forward name="result" path="/doAdd.jsp" />
        </action>
        <action path="/Welcome" forward="/welcomeStruts.jsp"/>
    </action-mappings>
   
    <controller processorClass="org.apache.struts.tiles.TilesRequestProcessor"/>

    <message-resources parameter="entity/ApplicationResource"/>
   
    <!-- ========================= Tiles plugin ===============================-->
        <plug-in className="org.apache.struts.tiles.TilesPlugin" >
        <set-property property="definitions-config" value="/WEB-INF/tiles-defs.xml" />
        <set-property property="moduleAware" value="true" />
    </plug-in>
   
    <!-- ========================= Validator plugin ================================= -->
    <plug-in className="org.apache.struts.validator.ValidatorPlugIn">
        <set-property
            property="pathnames"
            value="/WEB-INF/validator-rules.xml,/WEB-INF/validation.xml"/>
    </plug-in> 
</struts-config>

Note that all texts in red are the content you need to modify to be appropriated to your Web application.

Results
- add welcome page:


- result page:


- when entering incorrect data type: