How to Develop a Simple Crud Application Using Ejb3 and Web Dynpro

Transcription

1 How to Develop a Simple Crud Application Using Ejb3 and Web Dynpro Applies to: SAP Web Dynpro Java 7.1 SR 5. For more information, visit the User Interface Technology homepage. Summary The objective of this tutorial is to provide a simple example of a CRUD application using EJB 3 as model layer and Web Dynpro as view/controller layer. Author: Isaías Cristiano Barroso Company: Independent Consultant - Brazil Created on: 07 September 2008 Author Bio Isaías Cristiano Barroso has worked with SAP Technologies since He is an official instructor for NetWeaver Java. The prior experience of Isaías has focused on various Java technologies including development with open source frameworks and proprietary suites like Oracle SOA Suite. Isaías has worked to many companies as System Architect in the last 5 years. Currently he is involved with technologies such as Composition Application Framework, Visual Composer, Web Services and Web Dynpro, Process Integration, NetWeaver Administration and researches about possibilities use of new NetWeaver features NetWeaver Galaxy and Flash Islands) on the companies SAP AG 1

2 Table of Contents Introducion...3 Creating a dictionary project...4 Step 1: Creating the project...4 Step 2: Creating the table definition...7 Step 3: Deploying the dictionary...9 Creating EJB project...12 Step 1: Creating EJB project...12 Step 2: Enabling JPA Facet to project...15 Step 3: Mapping JPA Entity...21 Step 4: Create Session Bean...23 Creating Enterprise Application...26 Step 1: Create Enterprise Application...26 Step 2 : Building and deploying...30 Creating Web Dynpro Project...31 Step 1: Creating Web Dynpro Project...35 Next, select Web Dynpro...35 Step 2: Creating Web Dynpro Component...37 Step 3: Creating a Custom Controller...39 Step 4: Importing the EJB Model...40 Step 5: Creating context on custom controller...46 Step 6: Creating the crud search screen...50 Step 7: Creating and Testing Web Dynpro Application...61 Step 8: Creating the edit and create view...62 Step 9: Testing Application...79 Conclusion...79 Related Content...80 Disclaimer and Liability Notice SAP AG 2

3 Introducion This document will cover the process to develop a simple CRUD (Create, Retrieve, Update and Delete) application exploring the new characteristics of SAP NetWeaver CE 7.1 like Import of EJB Model, use of EJB 3 and JPA. The application will be developed to maintain a simple TODO list. To develop and run this sample will be necessary NetWeaver Developer Studio 7.1 and NetWeaver Application Server 7.1 This tutorial will be divided on follow sections: Creating a dictionary Project Creating a EJB Project Creating a Application Project Creating a Web Dynpro Project All development will be based on local development component Bellow follow screens that will be gotten on finish of this tutorial SAP AG 3

4 Creating a dictionary project The first step is to create a dictionary project to define the database table structure do use on application. To do this you ll need to create a Dictionary Development Component Project. Step 1: Creating the project Open your developer studio and click File -> New -> Project -> Development Infrastructure -> Development Component. The screen bellow will appear, then click Next 2008 SAP AG 4

5 Select dictionary and click next On the next screen select the Local Development -> My Components and click next 2008 SAP AG 5

6 After this we need fill the information about the development component. Then click Next and Finish. The DCs archive will be synchronized and a dialog can be show to change to dictionary perspective, click yes, and the project will be show on the dictionary perspective like the follow screen 2008 SAP AG 6

7 Step 2: Creating the table definition Expand the dictionary project, right click on Database Tables and select Create Table like is shown on next screen To purpose of tutorial, on the next screen leave the prefix table as TMP and put the suffix as TODO, then click on Finish. So a screen like the following will appear Now, we need to create the columns to TODO table SAP AG 7

8 Click on Add Column Button to add columns to table definition. Repeat the add column step, for the other two columns (TODO_DESCRIPTION and TODO_PRIORITY) 2008 SAP AG 8

9 Step 3: Deploying the dictionary To reduce complexity we ll deploy the dictionary using default system datasource. So assuming that a SID used was CE1, the table will be created on SAPCE1DB schema after deploy. Right click on dictionary project and choose Rebuild project to verify if all is fine SAP AG 9

10 After rebuild, if no errors occur, is the time to create archive and deploy the dictionary, to SAP Application Server. Right click on dictionary project and choose Create Archive. Right click on dictionary project and choose Deploy SAP AG 10

11 After successful deploy, the table will be created on default schema. Note: To visualize the database schema was used the Database Development perspective of Developer Studio and a connection was created using a MaxDB JDBC Driver. To reduce the number of tables listed, a filter was applied to get only tables that name starts with T SAP AG 11

12 Creating EJB project Now, we need create the EJB project, in this project a Session Bean 3.0 will developed to act as the Façade that will be accessed by Web Dynpro, additionally a JPA Entity will be mapped to interact with TODO database table created from dictionary project. Step 1: Creating EJB project On your developer studio click File -> New -> Project -> Development Infrastructure -> Development Component. The screen bellow will appear, then click Next 2008 SAP AG 12

13 Next, select J2EE -> EJB Module On the next screen, select the Local Development -> My Components and click next 2008 SAP AG 13

14 After this, we need to fill the information about the development component. Click on Next and another screen will appear to choose what is the JEE version will be used, keep 5.0 and click on Finish. Then click Finish. The DCs archive will be synchronized and a dialog can be show to change to J2EE perspective, click yes, and project will be show on the J2EE perspective SAP AG 14

15 Step 2: Enabling JPA Facet to project This step is important to make possible to mapping, automatically, of JPA Entity based on a data source (JDBC or Dictionary). As we have a dictionary we will map it from a dictionary, to show this feature, but the mapping can be done from database directly too. To use a dictionary as a data source, first open the Database Development perspective Window-> Open Perspective -> Other -> Database Development. After, you ll see a screen like bellow:: Right click on Databases node and select New, the following screen will appear to select the type of connection: 2008 SAP AG 15

16 Choose DDIC Design time and click Next, after this, fills the name of connection, description and select the option to Auto-connect as show on the following screen: Click Next to choose the dictionary project: Then click Next and a screen with Summary will appear, click Finish SAP AG 16

17 After finish, verify if the dictionary information was retrieved with success, as show the following screen: After this, go to Java EE perspective and right click on the EJB project and choose Properties-> Project Facets, the screen bellow will appear with the current Facets: 2008 SAP AG 17

18 Click on Modify Project to add JPA Facet to project: 2008 SAP AG 18

19 Click Next, select Platform Generic and Connection TodoAppDict, this steps are show on screen bellow: Click on Finish, and Facet will be installed as show screen bellow 2008 SAP AG 19

20 Click Ok, the project will be enabled to use JPA. When the JPA facet is added to EJB project, a file named persistence.xml and orm.xml are created to configure information about JPA, in this project we will change only persistence.xml, when this file is created the persistence unit name is a name of project, let's to change its name to a friendlier name. To do it, open the EJB project -> ejbmodule-> META-INF and open persistence.xml, after change the file as show bellow. From: To: <?xml version="1.0" encoding="utf-8"?> <persistence version="1.0" xmlns=" xmlns:xsi=" xsi:schemalocation=" <persistence-unit name="localdevelopment~localdevelopment~todo(2fejb~demo.sap.com"> <mapping-file> META-INF/orm.xml</mapping-file> </persistence-unit> </persistence> <?xml version="1.0" encoding="utf-8"?> <persistence version="1.0" xmlns=" xmlns:xsi=" xsi:schemalocation=" <persistence-unit name="todounit"> <mapping-file> META-INF/orm.xml</mapping-file> </persistence-unit> </persistence> <<< INSERT CONFIGURATION OF DATASOURCE >>> 2008 SAP AG 20

21 Step 3: Mapping JPA Entity Right click on EJB project, select JPA Tools -> Generate Entities. A screen will appear to fill some parameters to generate class. On package input sap.com.todo.ejb.entity, select TMP_TODO, change the Entity Name to Todo instead TmpTodo SAP AG 21

22 After click Finish, a new JPA Entity class will be generated on ejbmodule src folder. This class will contain JPA Annotations SAP AG 22

23 Step 4: Create Session Bean Through Session EJB we can access the CRUD methods to maintain the TODO table, in this section we will create a Session Bean to be the Façade of our simple application. To create a new Session Bean, right click on EJB project and select New -> EJB Session Bean 3.0 Fill EJB Class Name with TodoServiceBean and Default EJB Package with sap.com.todo.ejb.service. As the EJB and Web Dynpro will be at the same server just Local interface is required. Click Next, then click Finish 2008 SAP AG 23

24 After Finish, the interface and implementation to Session Bean will be generated like screen bellow. Now, we will insert the following methods signature on the interface public interface TodoServiceLocal { Todo create(todo todo); Todo update(todo todo); void delete(integer pk); List<Todo> findbydescription(string description); } After, declared methods on interface must to be implemented on the Session Bean, before to implement the methods is important lets clear that JPA Entity Manager will provide methods to manipulate Todo Entity. The JPA Entity Manager will be injected through the following public class AgenciaGerServiceBean implements AgenciaGerServiceLocal { private EntityManager em; When the code runs, the attribute em will be initialized with a instance of Entity Manager according with informations defined on persistence.xml file SAP AG 24

25 The code bellow, shows the complete code to Session Bean public class TodoServiceBean implements TodoServiceLocal private EntityManager em; public Todo create(todo todo) { em.persist(todo); return todo; } public void delete(integer pk) { Todo todo = em.find(todo.class, pk); public List<Todo> findbydescription(string description) { Query query=em.createnamedquery("todo.findbydescription"); description = description == null? "%%" : "%"+description+"%"; query.setparameter("description", description); List<Todo> result=query.getresultlist(); return result; } public Todo update(todo todo) { em.merge(todo); return todo; } } Note: The method findbydescription uses a named query Todo.findByDescription, this query needs to be defined on Entity. The Entity named query declaration will be show bellow. Todo.java query="select t FROM Todo t WHERE t.tododescription LIKE :description") }) public class Todo implements Serializable { } 2008 SAP AG 25

26 Creating Enterprise Application To deploy the EJB project, will necessary to create an Enterprise Application. Step 1: Create Enterprise Application On your developer studio click File -> New -> Project -> Development Infrastructure -> Development Component. The screen bellow will appear, then click Next: 2008 SAP AG 26

27 Next, select J2EE -> Enterprise Application On the next screen, select the Local Development -> My Components and click next 2008 SAP AG 27

28 After this, we need fill the information about the development component. After click Next, select what is the JEE version, in this case SAP AG 28

29 After click Next, select which the project will packed by this Enterprise Application, select the TODO EJB and click Finish. Before execute the build and deploy of Enterprise Application, is necessary put datasource information on persistence.xml configuration file. To it open the ejb project -> ejbmodule-> META-INF and edit the file, we need to input the <jta-data-source> as child of <persistence-unit> as showed bellow. <?xml version="1.0" encoding="utf-8"?> <persistence version="1.0" xmlns=" xmlns:xsi=" xsi:schemalocation=" <persistence-unit name="todounit"> <jta-data-source>todo/todods</jta-data-source> <mapping-file> META-INF/orm.xml</mapping-file> </persistence-unit> </persistence> Note: TODO/TODODS must be an Alias to System Data source 2008 SAP AG 29

30 Step 2 : Building and deploying To build and deploy the Enterprise Application project, open the Development Infrastructure perspective. Open Window -> Open Perspective -> Other -> Development Infrastructure Open Local Development -> My Components Right click on todo/app -> Deploy After successful deploy of Application, the last development component, Web Dynpro, will be created SAP AG 30

31 Creating Web Dynpro Project This is the last point to our application, the MVC Web Dynpro Application. In this application we will access the Enterprise Java Bean through of Enterprise Application that was developed previously. To access the EJB through EAR, is necessary to change the permissions of EJB Development Component allowing Entity Forwarding, with this change another Development Component, in this case, Enterprise Application will can reference the public part of EJB DC. To do it, open the Development Infrastructure perspective -> My Components -> Select todo/ejb. On component properties select the Permissions tab and select the option Entity Forwarding Allowed. It will appear like screen bellow. After this, build de project. The EJB DC contains two public parts, COMPILATION (client) and ASSEMBLY (ejbjar), they are show at screen bellow 2008 SAP AG 31

32 The Enterprise Application uses only ASSEMBLY part, to import the EJB, we need of compilation part. To see the current dependencies of Enterprise Application DC, select the todo/app then select tab dependencies: On the above image just ejbjar (ASSEMBLY) part was selected, now select the client (COMPILATION) and on Dependency Details of right side select Build Time. Now, the Application can access the public part COMPILATION from EJB DC, but, to Web Dynpro to access, we need to create a Public Part on Enterprise Application DC of COMPILATION type, that point to Entity of EJB DC SAP AG 32

33 Select todo/app, select Public Parts tab and click Add, put ejb_pp on Name and COMPILATION on Purpose, as show screen bellow After click Finish, right click on Public Part and select Reference Entities as screen bellow 2008 SAP AG 33

34 After, select My Components -> todo/ejb -> client as show screen bellow. After click Finish, build and deploy the Application project. Now, the project is ready to be imported by Web Dynpro as EJB Model, so the Web Dynpro project can be created SAP AG 34

35 Step 1: Creating Web Dynpro Project On your developer studio click File -> New -> Project -> Development Infrastructure -> Development Component. The screen bellow will appear, then click Next: Next, select Web Dynpro 2008 SAP AG 35

36 On the next screen, select Local Development -> My Components and click next After this, we need fill the information about the development component. Then click next and Finish. The DCs archive will be synchronized and a dialog can be show to change to Web Dynpro perspective, click yes and the project will be show on the Web Dynpro perspective SAP AG 36

37 Step 2: Creating Web Dynpro Component Now, we need create a Web Dynpro component that will be used to manage the EJB Session Bean, previously created. On Web Dynpro Explorer, expand the project and right click on Components and select Create Component, like show screen bellow: Put the name of component as CrudApp, select the option Default Window and Views like screen bellow: 2008 SAP AG 37

38 After, click Next, a screen like bellow, will appear After click Finish, the component will be created. At the screen bellow we have a view of the component SAP AG 38

39 Step 3: Creating a Custom Controller A custom controller will be created, in this controller the EJB Model will be mapped. Double click on Web Dynpro component CrudApp and the toolbar select the option Create Custom Controller and click at component diagram on right side. A new dialog will open, fill the name with CrudAppCust SAP AG 39

40 After this, the custom controller will shown at component diagram. Step 4: Importing the EJB Model Before start EJB Model import, is necessary to define the dependency between Web Dynpro and Enterprise Application project. To do it, on Development Infrastructure -> Local Development -> MyComponents and select todo/wdp. Select Dependencies tab and click add, then select MyComponents -> todo/app 2008 SAP AG 40

41 Click next and verify if Public Part is selected then click Finish After Finish, we can see the dependency as screen bellow SAP AG 41

42 Now, the EJB can be imported. To do it, open Web Dynpro perspective and Double Click CrudApp, then click on Create Model option, and click on Component Diagram. After this, a Wizard will open to select the model type, select Enterprise JavaBean Model SAP AG 42

43 Click next and fill Model Name as EJBCrudModel and fill Model Package as com.sap.demo.todo.wdp.model Click on Next and select todo/app Click on Next and select all available methods SAP AG 43

44 Click on Next and a screen with the classes that will be generated will be show. After, click on Next and the a screen with the classes will be show separated by groups, for each method will be generated a corresponding Request object and, to each method that contain return, will generate a Response object, finally Model classes will be generated at Others group SAP AG 44

45 Click on Next and a log will be show. Click Finish and model will be generated and will appear on Component Diagram as screen bellow SAP AG 45

46 Step 5: Creating context on custom controller In this step the context of custom controller will provide access to EJB through EJB Model. Select Create Data Link and click on CrudAppCust and drag and drop to EJBCrudModel. After, a screen with available methods will be show, select and drag and drop the update and findbydescription methods to left side. The next screen shows the process to findbydescription 2008 SAP AG 46

47 Repeat the process to update method. Note that return node has a problem, it occurs because already exists a node with the name return and Response, that was created previously to findbydescription. To solve it change the name of return node to returnupdate and ResponseUpdate. The next screen show the return node changed SAP AG 47

48 2008 SAP AG 48

49 After complete the mapping the context will be like screen bellow. Note: The EJB have 4 methods, and all method were imported, but just update and findbydescription were mapped to context, all methods will be used on the simple crud application. But only these will need to bind to UI. The others will be used just programmatically SAP AG 49

50 Step 6: Creating the crud search screen The search screen will be created using the CrudAppView, the first step is mapping the context to custom controller context. Click on Create Data Link and Drag and Drop to CrudAppCust. It is the same procedure of Step 5. When the next screen appears drag and drop the Request_TodoServiceLocal_findByDescription node to ViewController context. After click Finish and the mapping will be complete SAP AG 50

51 To get the search screen working correctly will be necessary initialize the node Request_TodoServiceLocal_findByDescription. To do it open the Java Editor of Custom Controller and locate the method wddoinit and put the following code. At others section of the Web Dynpro code, declare and initialize the model that will be used for other methods. This section can be found at end of file. others EJBCrudModel model = new EJBCrudModel(); //@@end //@@begin javadoc:wddoinit() /** Hook method called to initialize controller. */ //@@end public void wddoinit() { //@@begin wddoinit() EJBCrudModel model = new EJBCrudModel(); Request_TodoServiceLocal_findByDescription request = new Request_TodoServiceLocal_findByDescription(model); wdcontext.noderequest_todoservicelocal_findbydescription().bind(request); //@@end } 2008 SAP AG 51

52 After this, the method to call the search method needs to be created on Custom Controller. Select the Methods tab and click on New button, select Method and click next, after fill the name as searchtodo, after click finish. Select File-> Save All Select the method and right click, then select Navigate To -> Implementation javadoc:searchtodo() /** * Method declared by application. */ //@@end public void searchtodo( ) { //@@begin searchtodo() try { wdcontext.currentrequest_todoservicelocal_findbydescriptionelement(). modelobject().execute(); wdcontext.noderesponse().invalidate(); } catch (Exception e) { wdcomponentapi.getmessagemanager(). reportexception(e.getlocalizedmessage()); } //@@end } 2008 SAP AG 52

53 Now, the method searchtodo can be called by view. To do it, open CrudAppView and select Actions tab, click on New Button and put name SearchTodo 2008 SAP AG 53

54 Click on Finish and select File -> Save All Right click on SearchTodo action and select Navigate To -> Implementation Implement the method with the following code javadoc:onactionsearchtodo(serverevent) /** * Declared validating event handler. * wdevent generic event object provided by framework */ //@@end public void onactionsearchtodo(com.sap.tc.webdynpro.progmodel.api.iwdcustomevent wdevent ) { //@@begin onactionsearchtodo(serverevent) wdthis.wdgetcrudappcustcontroller().searchtodo(); wdcontext.noderesponse().invalidate(); //@@end } 2008 SAP AG 54

55 Now, we can create the UI to search. Open the CrudAppView and insert a Transparent Container as child of RootElement. Change the layout of RootElement to FlowLayout. Right click on it and select Apply Template, choose Form and click next 2008 SAP AG 55

56 Select Description and click next, after click Finish and the criteria input will show on search view SAP AG 56

57 Now, we need to put the response data on screen, to do it, select Root Element and select Apply Template then choose the Table option. Click Next and select return node and click Finish SAP AG 57

58 Click next, and place the todoid on the first position After select the table and change the width property to 700px SAP AG 58

59 Insert a Button as child of RootElement, change text property to Search. Apply the SearchTodo action to Button SAP AG 59

60 After this procedures, at outline of view, a screen like this should be appears. Now, change the labels according the following table: Default Label New Label description_label Description todoid ID tododescription Description todopriority Priority 2008 SAP AG 60

61 Step 7: Creating and Testing Web Dynpro Application Select Applications -> Create Application Set name CrudApp and click Next, select use existing component then Finish. Now, select the application and choose Deploy new Archive and Run SAP AG 61

62 A screen like bellow will appear, click on Search to make a simple test, no data will return, but It will certify that all is ok. On the nest Step we will create the edit/create page of CRUD. Step 8: Creating the edit and create view The EJB Model contains separated methods to edit and create a new record. Only one view will use the node Request_TodoServiceLocal_update to bind data for the two operations. Programmatically, based on a boolean attribute that will be created on custom controller context, the correct method will be called. To do it, let s to create the boolean attribute. Open the CrudAppCust context, right click on Context root -> New -> Attribute 2008 SAP AG 62

63 On the next screen, select the option manually and fill the name with updatemode, then select type boolean. This will indicate if the record is on update mode or create mode.. After this, click Finish. Two methods will be created to initialize the mode of record (initedit and initcreate). Go to Methods tab of Custom Controller and create these methods, after File-> Save All. The methods body must be in according with code bellow. javadoc:initedit() /** * Method declared by application. */ //@@end public void initedit( ) { //@@begin initedit() Request_TodoServiceLocal_update requestupdate = new Request_TodoServiceLocal_update(model); Todo todo = new Todo(model); WDCopyService.copyCorresponding(wdContext.currentReturnElement(), todo); requestupdate.settodo(todo); wdcontext.currentcontextelement().setupdatemode(true); wdcontext.noderequest_todoservicelocal_update().bind(requestupdate); //@@end } 2008 SAP AG 63

64 javadoc:initcreate() /** * Method declared by application. */ //@@end public void initcreate( ) { //@@begin initcreate() Request_TodoServiceLocal_update requestupdate = new Request_TodoServiceLocal_update(model); Todo todo = new Todo(model); requestupdate.settodo(todo); wdcontext.currentcontextelement().setupdatemode(false); wdcontext.noderequest_todoservicelocal_update().bind(requestupdate); //@@end } Note: Both methods are using the request update node, this strategy was adopted to reduce redundancy to build a view to each one (edit and create). The data of operations are the same, so isn t necessary to duplicate the code. The WDCopyServices was used to copy data of a node to another with the same structure. The updatemode attribute is initialized according the operation. The methods to initialize the context were created, now is necessary create a method to save the record, this method must to decide if a update or insert operation will be called, this will based on updatemode attribute. At the methods tab of CrudAppCust, create a new method named savetodo, then File-> Save All. After, put the code bellow in the method. //@@begin javadoc:savetodo() /** * Method declared by application. */ //@@end public void savetodo( ) { //@@begin savetodo() try{ if (wdcontext.currentcontextelement().getupdatemode()){ wdcontext.currentrequest_todoservicelocal_updateelement().modelobject().execute(); } else { Request_TodoServiceLocal_create requestcreate = new Request_TodoServiceLocal_create(model); requestcreate.settodo(wdcontext.currentrequest_todoservicelocal_updateelement(). modelobject().gettodo()); requestcreate.execute(); wdcontext.currentcontextelement().setupdatemode(true); } wdcomponentapi.getmessagemanager().reportsuccess("operation was completed with success"); } catch (Exception e){ wdcomponentapi.getmessagemanager().reportexception(e); } //@@end } 2008 SAP AG 64

65 To complete the CRUD, the remove operation must exists. To this, execute the previous step to create a new method named removetodo. After, put the code bellow in the implementation. //@@begin javadoc:removetodo() /** * Method declared by application. */ //@@end public void removetodo( ) { //@@begin removetodo() try{ Request_TodoServiceLocal_delete requestdelete = new Request_TodoServiceLocal_delete(model); Integer pk = wdcontext.currentrequest_todoservicelocal_updateelement(). modelobject().gettodo().gettodoid(); requestdelete.setpk(pk); requestdelete.execute(); wdcontext.nodereturn().removeelement(wdcontext.currentreturnelement()); wdcontext.nodereturn().invalidate(); wdcomponentapi.getmessagemanager().reportsuccess("operation was completed with success"); } catch (Exception e){ wdcomponentapi.getmessagemanager().reportexception(e); } //@@end } Note: To remove operation, the pk is retrieved of current record and passed to method of EJB. After, the current element is removed of result list SAP AG 65

66 The next step is create a new View to edit screen, select the Views of component, right click -> Create View On next screen, put view name as CrudAppEditView and click Finish SAP AG 66

67 Now, is necessary to map the context of CrudAppCust to CrudAppEditView context. To do it, open the CrudApp component diagram. Click on Create Data Link and Drag and Drop the data link from CrudAppEditView to CrudAppCust. A dialog to mapping will appear, in it drag and drop node update and updatemode attribute. Click on Finish and the mapping is ready. The diagram should be like screen bellow SAP AG 67

68 To build the edit/create view, open the CrudAppEditView and remove the DefaultTextView of RootElement. Insert a Group component child of RootElement, and right click and Apply Template. On next screen, select Form and click Next, then select the input parameters SAP AG 68

69 Click Next, and place id field on the first position. Click Finish and change the labels of fields according to table bellow. Default Label New Label todoid_label ID tododescription_label Description todopriority_label Priority Group_Header Todo Detail Now, insert two buttons on RootElement with text Save, Cancel and Delete, at the later step we will set the actions to they SAP AG 69

70 In this sample the ID will be input by user, so the field can be edited only to new records. To make this control, the attribute updatemode will be used. If in updatemode the field can t be edited. To do it, select the id field and select the property readonly, click on bind button and select the attribute updatemode.. On the next screen select the attribute updatemode SAP AG 70

71 After click OK, the readonly property will use the attribute to control the edit status. To navigate from a screen to another, the plugs need to be created, select the Window and double click, initially only CrudAppView is on diagram SAP AG 71

72 Click on Embed existing View, and then click on diagram. A dialog will open to choose what view must be embedded. Select CrudAppEditView. After click Finish, and the view will appear in the diagram. Create an Outbound Plug on CrudAppView with name ToEditView, and create an Inbound plug with name FromEditView SAP AG 72

73 Create an Outbound Plug on CrudAppEditView with name ToSearchView, and create an inbound plug with name FromSearchView SAP AG 73

74 Now create a link between inbound plugs and outbound plugs. After it, the navigation can be done between the views. Open CrudAppEditView, and go to Actions tab and create a new action named Cancel, select ToSearchView for FirePlug option. This action will return to search view SAP AG 74

75 After, click on Finish and create a new Action named Save Click Finish and then File-> Save All Go to Implementation of Save action SAP AG 75

76 At the implementation, put the following code. javadoc:onactionsave(serverevent) /** * Declared validating event handler. * wdevent generic event object provided by framework */ //@@end public void onactionsave(com.sap.tc.webdynpro.progmodel.api.iwdcustomevent wdevent ) { //@@begin onactionsave(serverevent) wdthis.wdgetcrudappcustcontroller().savetodo(); wdthis.wdfireplugtosearchview(); //@@end } Now, create the last action, Delete. To this, create a new Action named Delete Click Finish and then File-> Save All Go to Implementation of Delete action SAP AG 76

77 At the implementation, put the following code. javadoc:onactiondelete(serverevent) /** * Declared validating event handler. * wdevent generic event object provided by framework */ //@@end public void onactiondelete(com.sap.tc.webdynpro.progmodel.api.iwdcustomevent wdevent ) { //@@begin onactiondelete(serverevent) wdthis.wdgetcrudappcustcontroller().removetodo(); wdthis.wdfireplugtosearchview(); //@@end } Now, is necessary to set the actions to buttons Save, Cancel and Delete. To this, select the button and change the property onaction to Save, Cancel and Delete respectively. After, the edit view is fully configured. Now we need to add the edit and create actions to search view. Open the CrudAppView and insert two new button, Create and Edit. Note that buttons doesn t have actions associated. So let s to create the actions, select the Actions tab and create a new action named Create and select Fire Plug ToEditView, click on Finish, then click on save menu and goes to implementation method and put the following code. //@@begin javadoc:onactioncreate(serverevent) /** * Declared validating event handler. * wdevent generic event object provided by framework */ //@@end public void onactioncreate(com.sap.tc.webdynpro.progmodel.api.iwdcustomevent wdevent ) { //@@begin onactioncreate(serverevent) wdthis.wdgetcrudappcustcontroller().initcreate(); wdthis.wdfireplugtoeditview(); //@@end } After, create a new action named Edit and select ToEditView for the Fire Plug option, click on Finish. Click on save menu and goes to implementation method and put the following code SAP AG 77

78 javadoc:onactionedit(serverevent) /** * Declared validating event handler. * wdevent generic event object provided by framework */ //@@end public void onactionedit(com.sap.tc.webdynpro.progmodel.api.iwdcustomevent wdevent ) { //@@begin onactionedit(serverevent) wdthis.wdgetcrudappcustcontroller().initedit(); wdthis.wdfireplugtoeditview(); //@@end } With the actions created, set the actions to respective buttons (Create and Edit) SAP AG 78

79 Step 9: Testing Application Select CrudApp and Deploy new Archive and Run. The first screen provides description criteria to find TODOs, and a button to edit an existing TODO and another to create a new. At edit view, you can save or delete a existing TODO. To back to search screen the Cancel button can be used. Conclusion This is a very simple application that shows the development using EJB 3 and Web Dynpro. This can be improved with forms validation [Tutorial] 2008 SAP AG 79

80 Related Content Getting Started with Java Persistence API and SAP JPA 1.0 SAP NetWeaver J2EE Preview: Application Development with the EJB 3.0 Programming Model Basics of the Java Persistence API Understanding the Entity Manager For more information, visit the User Interface Technology homepage SAP AG 80

81 Disclaimer and Liability Notice This document may discuss sample coding or other information that does not include SAP official interfaces and therefore is not supported by SAP. Changes made based on this information are not supported and can be overwritten during an upgrade. SAP will not be held liable for any damages caused by using or misusing the information, code or methods suggested in this document, and anyone using these methods does so at his/her own risk. SAP offers no guarantees and assumes no responsibility or liability of any type with respect to the content of this technical article or code sample, including any liability resulting from incompatibility between the content within this document and the materials and services offered by SAP. You agree that you will not hold, or seek to hold, SAP responsible or liable with respect to the content of this document SAP AG 81