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not-in-svn - Inbound JCA example Java EE sample applications singletonejb-javaee6 - A simple JSF+Singleton+ejb injection application

Application Overview

This sample application demonstrates a simple order system which can get, delete, and edit ordering data using RESTful Web services. This RESTful Web services application works at XML message level. When a user create a new order or edit an existing one, the resource data is converted into XML schema for processing. This web service is exposed as a Servlet in the Geronimo application server. See RESTful Web services for more information on the concept.

Application contents

The restfulorder-javaee6 application is deployed as a WAR to the application server. The overview of the structural content of this WAR file is given as follows.

|-restfulorder-javaee6.war
   +-rest
	+- restfulorder
	+- Support.js
   +-WEB-INF
	+- web.xml
        +- classes
               +- org.apache.geronimo.samples.javaee6.restfulorder
               +- META-INF
   +-META-INF

The org.apache.geronimo.samples.javaee6.restfulorder package consists of the following files.

+- org.apache.geronimo.samples.javaee6.restfulorder
   +-service
	+- RestfulordersResource.class
	+- RestfulorderResource.class
   +-config
	+- ApplicationConfig.class
   +-converter
	+- RestfulorderConverter.class
	+- RestfulordersConverter.class
   +-entities
   +-JPASessionBeans

where,

  • The service folder contains the resource classes of the RESTful application.
  • The config folder contains the servlet class that extends javax.ws.rs.core.Application to configure the application classes within a JAX-RS runtime. The javax.ws.rs.core.Application class provides methods that can specify a set of root resources and providers accessible from a specified application path. This way users can specify several groups of resources in a single application.
  • The converter folder contains Java Architecture for XML Binding (JAXB) annotated classes to support the processing of XML in requests and responses.

Application implementation

RestfulordersResource is a resource class that uses JAX-RS annotations to implement the corresponding Web resource.

RestfulordersResource.java
package org.apache.geronimo.samples.javaee6.restfulorder.service;

import java.util.Collection;
import javax.ws.rs.Path;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Produces;
import javax.ws.rs.Consumes;
import javax.ws.rs.PathParam;
import javax.ws.rs.QueryParam;
import javax.ws.rs.DefaultValue;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.UriInfo;
import javax.persistence.EntityManager;
import org.apache.geronimo.samples.javaee6.restfulorder.converter.RestfulordersConverter;
import org.apache.geronimo.samples.javaee6.restfulorder.converter.RestfulorderConverter;
import javax.persistence.PersistenceContext;
import javax.ejb.Stateless;
import org.apache.geronimo.samples.javaee6.restfulorder.entities.Restfulorder;


@Path("/restfulorders/")
@Stateless
public class RestfulordersResource {
    @javax.ejb.EJB
    private RestfulorderResource restfulorderResource;
    @Context
    protected UriInfo uriInfo;
    @PersistenceContext(unitName = "RestfulProduct2PU")
    protected EntityManager em;
  
    /** Creates a new instance of RestfulordersResource */
    public RestfulordersResource() {
    }

    /**
     * Get method for retrieving a collection of Restfulorder instance in XML format.
     *
     * @return an instance of RestfulordersConverter
     */
    @GET
    @Produces({"application/xml", "application/json"})
    public RestfulordersConverter get(@QueryParam("start")
                                      @DefaultValue("0")
    int start, @QueryParam("max")
               @DefaultValue("10")
    int max, @QueryParam("expandLevel")
             @DefaultValue("1")
    int expandLevel, @QueryParam("query")
                     @DefaultValue("SELECT e FROM Restfulorder e")
    String query) {
        return new RestfulordersConverter(getEntities(start, max, query), uriInfo.getAbsolutePath(), expandLevel);
    }

    /**
     * Post method for creating an instance of Restfulorder using XML as the input format.
     *
     * @param data an RestfulorderConverter entity that is deserialized from an XML stream
     * @return an instance of RestfulorderConverter
     */
    @POST
    @Consumes({"application/xml", "application/json"})
    public Response post(RestfulorderConverter data) {
        System.out.println("before resolve,in post");
        Restfulorder entity = data.resolveEntity(em);
        createEntity(data.resolveEntity(em));
        return Response.created(uriInfo.getAbsolutePath().resolve(entity.getId() + "/")).build();
    }

    /**
     * Returns a dynamic instance of RestfulorderResource used for entity navigation.
     *
     * @return an instance of RestfulorderResource
     */
    @Path("{id}/")
    public RestfulorderResource getRestfulorderResource(@PathParam("id")
    Integer id) {
        restfulorderResource.setId(id);
        restfulorderResource.setEm(em);
        return restfulorderResource;
    }

    /**
     * Returns all the entities associated with this resource.
     *
     * @return a collection of Restfulorder instances
     */
    protected Collection<Restfulorder> getEntities(int start, int max, String query) {
        return em.createQuery(query).setFirstResult(start).setMaxResults(max).getResultList();
    }

    /**
     * Persist the given entity.
     *
     * @param entity the entity to persist
     */
    protected void createEntity(Restfulorder entity) {
        em.persist(entity);
    }
}

where,

  • @Path("/restfulorders/") is the annotation that defines the relative URI to your resource. The base URI is provided by the combination of your hostname, port, application context root, and any URI pattern mappings in the application's web.xml file. For example, the URI for the resource presented by this resource class can be http://localhost:8080/restfulorder-javaee6/resources/restfulorders/.
  • @Path("{id}/") annotates a sub-resource locator which returns a RestfulorderResource object to handle HTTP requests. The id parameter in this annotation defines the relative URI under /restfulorders/id to the resource.
  • @Context is used in this resource class to inject an instance of UriInfo into the class field.
  • UriInfo instances can provide information on the components of a request URI.
  • @GET and @POST are request method designators for annotating resource methods in a resource class. Other common request method designators include @PUT, @DELETE, and @HEAD.
  • @Consumes and @Produces annotations are used to declare the supported request and response media types. In this resource class, the post and get methods both support application/xml and application/json.

ApplicationConfig is a servlet that extends the javax.ws.rs.core.Application class to configure the application classes within a JAX-RS runtime.

ApplicationConfig.java
package org.apache.geronimo.samples.javaee6.restfulorder.config;

@javax.ws.rs.ApplicationPath("resources")
public class ApplicationConfig extends javax.ws.rs.core.Application {
}

where,

  • @javax.ws.rs.ApplicationPath is an annotation that helps to specify the resource path of the application. The value of this annotation is used as the servlet URL pattern. For example, the URI for the resource presented in this application can be http://localhost:8080/restfulorder-javaee6/resources/restfulorders/, where /resources is the servlet URL. You can also specify this URL patterns in your web.xml file if this annotation is absent.
  • javax.ws.rs.core.Application is a class that provides the getClasses and getSingletons methods that can specify a set of root resources and providers accessible from a specified application path respectively. The ApplicationConfig class uses the default implementations of javax.ws.rs.core.Application subclass getClasses and getSingletons methods that return empty sets. In this case, when both methods return empty sets, all root resource classes and providers packaged in the application are included in the published JAX-RS application.

RestfulordersConverter is a Java Architecture for XML Binding (JAXB) annotated class that support the processing of XML in requests and responses.

RestfulordersConverter.java
package org.apache.geronimo.samples.javaee6.restfulorder.converter;

import java.net.URI;
import java.util.Collection;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlTransient;
import javax.xml.bind.annotation.XmlAttribute;
import java.util.ArrayList;
import org.apache.geronimo.samples.javaee6.restfulorder.entities.Restfulorder;

@XmlRootElement(name = "restfulorders")
public class RestfulordersConverter {
    private Collection<Restfulorder> entities;
    private Collection<RestfulorderConverter> items;
    private URI uri;
    private int expandLevel;
  
    /** Creates a new instance of RestfulordersConverter */
    public RestfulordersConverter() {
    }

    /**
     * Creates a new instance of RestfulordersConverter.
     *
     * @param entities associated entities
     * @param uri associated uri
     * @param expandLevel indicates the number of levels the entity graph should be expanded
     */
    public RestfulordersConverter(Collection<Restfulorder> entities, URI uri, int expandLevel) {
        this.entities = entities;
        this.uri = uri;
        this.expandLevel = expandLevel;
        getRestfulorder();
    }
......

where,

This application uses the Asynchronous JavaScript and XML (Ajax) technique to combine Java technologies, XML, and JavaScript for the web service applications to uses client-side scripting to exchange data with the server. The JavaScript for performing Ajax interactions is support.js.

support.js
var rjsSupport = {

    proxy : "",
    
    getHttpProxy: function() {
        return this.proxy;
    },
    
    setHttpProxy: function(proxy_) {
        this.proxy = proxy_;
    },
    
    isSetHttpProxy: function() {
        return this.getHttpProxy().length > 0;
    },

    getHttpRequest: function() {
        var xmlHttpReq;
        try
        {    // Firefox, Opera 8.0+, Safari, IE7.0+
            xmlHttpReq=new XMLHttpRequest();
        }
        catch (e)
        {    // Internet Explorer 6.0+, 5.0+
            try
            {
                xmlHttpReq=new ActiveXObject("Msxml2.XMLHTTP");
            }
            catch (e)
            {
                try
                {
                    xmlHttpReq=new ActiveXObject("Microsoft.XMLHTTP");
                }
                catch (e)
                {
                    this.debug("Your browser does not support AJAX!");
                }
            }
        }
        return xmlHttpReq;
    },
    
    findUrl : function(url, method) {
        var url2 = url;
        if(this.isSetHttpProxy())
            url2 = this.getHttpProxy()+"?method="+method+"&url="+url2;
        return url2;
    },

    findMethod : function(method) {
        var method2 = method;
        if(method != "GET" && this.isSetHttpProxy())
            method2 = "POST";
        return method2;
    },

    open : function(method2, url2, mimeType, paramLen, async) {

        //Change url and method if using http proxy
        var url = this.findUrl(url2, method2);
        var method = this.findMethod(method2);

        //add timestamp to make url unique in case of IE7
        var timestamp = new Date().getTime();
        if(url.indexOf("?") != -1)
            url = url+"&timestamp="+timestamp;
        else
            url = url+"?timestamp="+timestamp;

        var xmlHttpReq = this.getHttpRequest();
        if(xmlHttpReq == null) {
            this.debug('Error: Cannot create XMLHttpRequest');
            return null;
        }
        try {
            netscape.security.PrivilegeManager.enablePrivilege ("UniversalBrowserRead");
        } catch (e) {
        //this.debug("Permission UniversalBrowserRead denied.");
        }
        try {
            xmlHttpReq.open(method, url, async);
        } catch( e ) {
            this.debug('Error: XMLHttpRequest.open failed for: '+url+' Error name: '+e.name+' Error message: '+e.message);
            return null;
        }
        if (mimeType != null) {
            if(method == 'GET') {
                //this.debug("setting GET accept: "+mimeType);
                xmlHttpReq.setRequestHeader('Accept', mimeType);
            } else if(method == 'POST' || method == 'PUT'){
                //this.debug("setting content-type: "+mimeType);
                //Send the proper header information along with the request
                xmlHttpReq.setRequestHeader("Content-Type", mimeType);
                xmlHttpReq.setRequestHeader("Content-Length", paramLen);
                xmlHttpReq.setRequestHeader("Connection", "close");
            }
        }
        //For cache control on IE7
        xmlHttpReq.setRequestHeader("Cache-Control", "no-cache");
        xmlHttpReq.setRequestHeader("Pragma", "no-cache");
        xmlHttpReq.setRequestHeader("Expires", "-1");

        return xmlHttpReq;
    },

    loadXml : function(xmlStr) {
        var doc2;
        // code for IE
        if (window.ActiveXObject)
        {
            doc2=new ActiveXObject("Microsoft.XMLDOM");
            doc2.async="false";
            doc2.loadXML(xmlStr);
        }
        // code for Mozilla, Firefox, Opera, etc.
        else
        {
            var parser=new DOMParser();
            doc2=parser.parseFromString(xmlStr,getDefaultMime());
        }
        return doc2;
    },

    findIdFromUrl : function(u) {
        var li = u.lastIndexOf('/');
        if(li != -1) {
            var u2 = u.substring(0, li);      
            var li2 = u2.lastIndexOf('/');
            u2 = u.substring(0, li2);
            return u.substring(li2+1, li);
        }
        return -1;
    },

    get : function(url, mime) {
        var xmlHttpReq = this.open('GET', url, mime, 0, false);
        try {
            xmlHttpReq.send(null);
            if (xmlHttpReq.readyState == 4) {
                var rtext = xmlHttpReq.responseText;
                if(rtext == undefined || rtext == '' || rtext.indexOf('HTTP Status') != -1) {
                    if(rtext != undefined)
                        this.debug('Failed XHR(GET, '+url+'): Server returned --> ' + rtext);
                    return '-1';
                }
                return rtext;
            }
        } catch( e ) {
            this.debug('Caught Exception; name: [' + e.name + '] message: [' + e.message+']');
        }
        return '-1';
    },

    post : function(url, mime, content) {
        var xmlHttpReq = this.open('POST', url, mime, content.length, false);

        try {
            xmlHttpReq.send(content);
            if (xmlHttpReq.readyState == 4) {
                var status = xmlHttpReq.status;
                if(status == 201) {
                    return true;
                } else {
                    this.debug('Failed XHR(POST, '+url+'): Server returned --> ' + status);
                }
            }
        } catch( e ) {
            this.debug('Caught Exception; name: [' + e.name + '] message: [' + e.message+']');
        }
        return false;
    },

    put : function(url, mime, content) {
        var xmlHttpReq = this.open('PUT', url, mime, content.length, false);
        try {
            xmlHttpReq.send(content);
            if (xmlHttpReq.readyState == 4) {
                var status = xmlHttpReq.status;
                if(status == 204) {
                    return true;
                } else {
                    this.debug('Failed XHR(PUT, '+url+'): Server returned --> ' + status);
                }
            }
        } catch( e ) {
            this.debug('Caught Exception; name: [' + e.name + '] message: [' + e.message+']');
        }
        return false;
    },

    delete_ : function(url) {
        var xmlHttpReq = this.open('DELETE', url, 'application/xml', 0, false);
        try {
            xmlHttpReq.send(null);
            if (xmlHttpReq.readyState == 4) {
                var status = xmlHttpReq.status;
                if(status == 204) {
                    return true;
                } else {
                    this.debug('Failed XHR(DELETE, '+url+'): Server returned --> ' + status);
                }
            }
        } catch( e ) {
            this.debug('Caught Exception; name: [' + e.name + '] message: [' + e.message+']');
        }
        return false;
    },

    debug : function(message) {
        var dbgComp = document.getElementById("dbgComp");
        if(dbgComp == null) {
            dbgComp = document.createElement("div");
            dbgComp.setAttribute("id", "dbgComp");
            dbgComp.style.border = "#2574B7 1px solid";
            dbgComp.style.font = "12pt/14pt sans-serif";
            var br = document.createElement("div");
            document.getElementsByTagName("body")[0].appendChild(br);
            br.innerHTML = '<br/><br/><br/>';
            document.getElementsByTagName("body")[0].appendChild(dbgComp);
            if((typeof rjsConfig!="undefined") && rjsConfig.isDebug) {
                dbgComp.style.display = "";
            } else {
                dbgComp.style.display = "none";
            }
            var tab = 'width: 20px; border-right: #2574B7 1px solid; border-top: #2574B7 1px solid; border-left: #2574B7 1px solid; border-bottom: #2574B7 1px solid; color: #000000; text-align: center;';
            var addActionStr = '<div style="'+tab+'"><a style="text-decoration: none" href="javascript:rjsSupport.closeDebug()"><span style="color: red">X</span></a></div>';        
            dbgComp.innerHTML = '<table><tr><td><span style="color: blue">Rest Debug Window</span></td><td>'+addActionStr + '</td></tr></table><br/>';
        }
        var s = dbgComp.innerHTML;
        var now = new Date();
        var dateStr = now.getHours()+':'+now.getMinutes()+':'+now.getSeconds();
        dbgComp.innerHTML = s + '<span style="color: red">rest debug('+dateStr+'): </span>' + message + "<br/>";
    },
    
    closeDebug : function() {
        var dbgComp = document.getElementById("dbgComp");
        if(dbgComp != null) {
            dbgComp.style.display = "none";
            dbgComp.innerHTML = '';
        }
    }
}

where,

  • XMLHttpRequest is a JavaScript object used to send HTTP or HTTPS requests directly to a web server and load the server response data directly back into the script. In this application, an XMLHttpRequest instance xmlHttpReq is created to help a client-side script perform HTTP requests. The HTTP method to use for the request, the destination URL, and the request content type are set on the XMLHttpRequest object with the open function when initializing the request.
  • open is the function that opens a connection to the server resource at the specified URL (URL2) for the specified method (method2). This function initializes the HTTP and HTTPS requests of the XMLHttpRequest object and must be invoked prior to the actual sending of a request.
  • setRequestHeader is a method of the XMLHttpRequest object that is used to set HTTP headers to be send with the request.
  • get, post, put and delete are functions responsible for dispatching requests. Each function first obtains an instance of XMLHttpRequest and initialize it with open. Then the requests are sent to the web server and will arrive on the server just like any other HttpServletRequest.
  • send is the function used to send requests to the web server. It accepts a single parameter that can contain the content to be sent with the request. The requests perform like HttpServletRequests on the web server and after parsing the request parameters, the servlet will invoke the necessary application logic. For this application, the get, post, put and delete methods from RestfulordersResource and RestfulorderResource classes are called according to the request type.

Testing of the Sample

Launch the application after deploying it on your server. Your browser shall display the showAll.jsp page. Add a new order with the link at the bottom of the page and the data applied for the order is contained at http://localhost:8080/restfulorder-javaee6/resources/restfulorders/id in XML format, where id is the unique id value you defined for your order. This order resource is also displayed on the showAll.jsp page after saving the data.

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