How to pass selected row data from datatable between two beans

Question

I've got a datatable with values in which I get from my DB. In my class myBean, I've got an Variable of type User to store the selected row. It just can be selected one row. Now I want to call this Variable from an other bean which is called printUser to get the selected User.

But it always prints null.

View

<p:dataTable id="userDT" var="user" value="#{myBean.getUserList()}" selection="#{myBean.selectedUser}" 
             rowKey="#{user.id}" >

    <p:column selectionMode="single" style="width:16px;text-align:center"/>

    <p:column width="200" headerText="ID">
        <h:outputText value="#{user.id}" />
    </p:column>

    <p:column width="200" headerText="Firstname">
        <h:outputText value="#{user.firstname}" />
    </p:column>

    <p:column width="250" headerText="Lastname">
        <h:outputText value="#{user.lastname}" />
    </p:column>

</p:dataTable>

myBean

@Named(value = "myBean")
@ManagedBean
@SessionScoped
public class myBean implements Serializable {
    private static final long serialVersionUID = 1L;

    private User selectedUser = new User();

    public myBean() {

    }

    public List<User> getUserList() {

        ...    
    }

    public Patient getSelectedUser() {
        return selectedUser;
    }

    public void setSelectedUser(User selectedUser) {
        this.selectedUser= selectedUser;

    }

}

User.java

public class User {

    private Integer id;
    private String firstname;
    private String lastname;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getFirstname() {
        return firstname;
    }

    public void setFirstname(String firstname) {
        this.firstname = firstname;
    }

    public String getLastname() {
        return lastname;
    }

    public void setLastname(String lastname) {
        this.lastname = lastname;
    }

}

printUser

@Named(value = "printUser")
@ManagedBean
@RequestScoped
public class printUser {

    public printUser() {

    }

    public void getSelectedUserData(){
        myBean bean = new myBean();
        User user = new User();

        user = bean.getSelectedUser();

        System.err.println("UserID: " + user.getID());
    }

}

Hope you undertand my Problem. Thanks alot Excuse my English

You can just inject myBean into printUser. But you should clean up your annotations - either use CDI beans or managed beans. You use both. And also use uppercase for class names — Jaqen H'ghar, Mar 15 '16 at 16:49
Please take a step back, find a good JSF2(.2) with CDI tutorial and use that. In the mean time try to pick up some basic java code knowledge — Kukeltje, Mar 15 '16 at 19:22

The Bitman · Accepted Answer · 2016-03-15T20:29:58.247

This is an example to use the entity of the selected row in the same page and in another page. The example use Lombok Getter,Setter and Data annotations for shortness:

The entity for the DataTable:

    @Entity
    @Data
    @TableGenerator( name = "GEN_TestEntity1", table = "ID_Generator", pkColumnName = "GEN_KEY", pkColumnValue = "GEN_TestEntity1", valueColumnName = "GEN_VALUE" )
    @NamedQuery( name = TestEntity1.QUERY_ALL_TESTENTITY1, query = "SELECT te1 FROM TestEntity1 te1" )
    public class TestEntity1 implements Serializable
    {
      public static final String QUERY_ALL_TESTENTITY1 = "query_All_TestEntity1";
      private static final long serialVersionUID = 1L;
      @Id
      @GeneratedValue( strategy = GenerationType.TABLE, generator = "GEN_TestEntity1" )
      private int id;

      @Column
      private String name;

    }

The ManagedBean as a controller:

    @ManagedBean
    @SessionScoped
    public class EntityBean
    {
      @EJB
      private EntitySER entitySER;

      @Getter
      @Setter
      private TestEntity1 selectedEntity;

      public List<TestEntity1> getAllTestEntity1()
      {
        return entitySER.getAllTestEntity1();
      }

      public void onRowSelect( SelectEvent event_ )
      {
      }

    }

Another ManagedBean which uses the first one (if you really want it):

    @ManagedBean
    @RequestScoped
    public class AnotherBean
    {
      @ManagedProperty( value="#{entityBean}" )
      private EntityBean entityBean;

      ...    
    }

The stateless session bean:

    @Stateless
    @LocalBean
    public class EntitySER
    {
      @PersistenceContext
      private EntityManager em;

      public List<TestEntity1> getAllTestEntity1()
      {
        Query q = em.createNamedQuery( TestEntity1.QUERY_ALL_TESTENTITY1 );
        return q.getResultList();
      }
    }

The index page (index.xhtml):

    <?xml version='1.0' encoding='UTF-8' ?>
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml"
          xmlns:h="http://xmlns.jcp.org/jsf/html"
          xmlns:p="http://primefaces.org/ui"
          xmlns:f="http://xmlns.jcp.org/jsf/core">
      <h:head>
        <title>Page 1</title>
      </h:head>
      <h:body>
        <h:form id="form">
          <p:dataTable id="table_TestEntity1" value="#{entityBean.allTestEntity1}" var="entity" selection="#{entityBean.selectedEntity}" 
                       rowKey="#{entity.id}" selectionMode="single">
            <p:ajax event="rowSelect" listener="#{entityBean.onRowSelect}" update=":form:entID :form:entName"/>
            <p:column>
              #{entity.id}
            </p:column>
            <p:column>
              #{entity.name}
            </p:column>
          </p:dataTable>
          <p>
            <h:outputLabel id="entID" value="#{entityBean.selectedEntity.id}"/>:
            <h:outputLabel id="entName" value="#{entityBean.selectedEntity.name}"/>
          </p>
          <p>
            <h:commandButton value="Page 2" action="/faces/another.xhtml"/>
          </p>
        </h:form>
      </h:body>
    </html>

The another Page (another.xhtml):

    <?xml version='1.0' encoding='UTF-8' ?>
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml"
          xmlns:h="http://xmlns.jcp.org/jsf/html">
      <h:head>
        <title>Another Page</title>
      </h:head>
      <h:body>
        <p>
          The selected entity: #{entityBean.selectedEntity.id}:#{entityBean.selectedEntity.name}
        </p>
        <h:form>
          <h:commandButton value="Back" action="/faces/index.xhtml"/>
        </h:form>
      </h:body>
    </html>

How to pass selected row data from datatable between two beans

1 Answers1