Hibenate 4.2 Insert, Fetch Data Example

Insert Data

In the previous example i taught you how to use hibernate in your application with configuration and JPA annotations. today i shall be talking about how to insert and fetch data from table which is persisted in database.
this is linked to the previous tutorial : Hibernate Tutorial

Test is entity class and it is persisted in the database. to insert data inside table of database. you just need to create an object of entity class which Test and add data by using its setter methods. like this:

Test test = new Test();
test.setPassword("password");
test.setUsername("username");

after doing this. you need to create a hibernate session object like this. 

Session session = configuration.buildSessionFactory().openSession();

session.beginTransaction(); 
//it means that you are going to make a transaction with //database.

session.saveOrUpdate(test); 
// saveOrUpdate method works like if there is no record exist in //the table then the above data will be inserted if it exists //then the following record will be updated.

session.getTransaction().commit();
session.close();

Fetch Data from Database

After creating session object from the configuration file. you only need to add following line of code:
List<Test> list = session.createQuery("from Test").list();
// Test is the entity class. and this HQL query. you can also add 
// SQL into it like select * from Test

// Showing Outut of the data

for(int i=0;i<list.size();i++){
System.out.println(list.get(i).username);

}

Hibernate 4.2 with JPA Annotations example using PostgreSQL Database

Required Libraries for Hibernate 4.2

• antlr-2.7.7.jar
• dom4j-1.6.1.jar
• hibernate-commons-annotations-4.0.1.Final.jar
• hibernate-core-4.2.1.Final.jar
• hibernate-jpa-2.0-api-1.0.1.Final.jar
• javassist-3.15.0-GA.jar
• jboss-logging-3.1.0.GA.jar
• jboss-transaction-api_1.1_spec-1.0.1.Final.jar
• postgresql-9.2-1002.jdbc3.jar *

 * Database driver file.

just keep these annotations in your mind while using Hibernate in your application.

JPA Annotations

• Entity
• Id
• GeneratedValue

if you want that you java class may persist in the database with the same name you need to add @Entity annotation at the class level. 

@Entity

public class Test{}

now it will persist into the database with a table name "test". if you want to change the name of the table then you need to add name attribute of Entity. like this @Entity(name = "TableName"). Entity class must implement serializable interface. Serializable interface acts as a mask for the object and objects retain their identity acorss the network. 

Adding Columns into Table

adding columns is nothing difficult it is same you are defining data members in class. like this.

@Entity

public class Test implements Serializable{

int id;

String username;

String password;

        @Id

@GeneratedValue(strategy = GenerationType.IDENTITY)

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getUsername() {

return username;

}

public void setUsername(String username) {

this.username = username;

}

public String getPassword() {

return password;

}

public void setPassword(String password) {

this.password = password;

}

}

@Id annotation is to define a primary key of table and i have made it auto generated. now define an xml file to define this entity class and make common configuration like database name, username, password, host name. 

hibernate.cfg.xml file code:

<!DOCTYPE hibernate-configuration PUBLIC

"-//Hibernate/Hibernate Configuration DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>

        <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>

        <property name="hibernate.connection.password">umairbaig</property>

        <property name="hibernate.connection.url">jdbc:postgresql://localhost:5432/imageDB</property>

        <property name="hibernate.connection.username">postgres</property>

        <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>

  <mapping class="Test"/>

    </session-factory>

</hibernate-configuration>

When you are done configuration inside main method add these lines:

public static void main(String[] args) {

AnnotationConfiguration configuration = new AnnotationConfiguration();

configuration.configure();

// if your xml file name is hibernate.cfg.xml then you dont need //to pass argument inside configure();

new SchemaExport(configuration).create(true, true);

}

Database table is created with the following columns;

Table Name test

Columns:

• id (Primary Key)
• username
• password

Image Uploading and Rendering from Database in JSF(Primefaces)

Add.xhtml  

    <h:form id="add-form" enctype="multipart/form-data">
             <p:growl id="messages" showDetail="true"/>
             <h:panelGrid columns="2">
                  <p:outputLabel for="choose" value="Choose Image :" />
                  <p:fileUpload id="choose" validator="#{productController.validateFile}" multiple="false" allowTypes="/(\.|\/)(gif|jpe?g|png)$/"  value="#{productController.file}" required="true" mode="simple"/>
                <p:commandButton value="Submit" ajax="false" update="messages" id="save-btn" actionListener="#{productController.saveProduct}"/>
             </h:panelGrid>
    </h:form>

 
Here is Managed Bean Code:

    @ManagedBean
  @RequestScoped
    public class ProductController implements Serializable{
    private ProductBean bean;
    @ManagedProperty(value = "#{ProductService}")
    private ProductService productService;
    private StreamedContent content;
    private UploadedFile file;
    public StreamedContent getContent() {
    FacesContext context = FacesContext.getCurrentInstance();
   
    if (context.getCurrentPhaseId() == PhaseId.RENDER_RESPONSE) {
               return new DefaultStreamedContent();
           }
    else{
    String imageId = context.getExternalContext().getRequestParameterMap().get("id");
    Product product = getProductService().getProductById(Integer.parseInt(imageId));
    return new DefaultStreamedContent(new ByteArrayInputStream(product.getProductImage()));
    }
    }
    public ProductController() {
    bean = new ProductBean();
    }
   
    public void setContent(StreamedContent content) {
    this.content = content;
    }
    public UploadedFile getFile() {
    return file;
    }
    
    public void setFile(UploadedFile file) {
    this.file = file;
    }
    public void saveProduct(){
    try{
    Product product = new Product();
    product.setProductImage(getFile().getContents());
   
    getProductService().saveProduct(product);
    file = null;
   
    }
    catch(Exception ex){
    ex.printStackTrace();
    }
    }
    public void validateFile(FacesContext ctx,
                UIComponent comp,
                Object value) {
    List<FacesMessage> msgs = new ArrayList<FacesMessage>();
    UploadedFile file = (UploadedFile)value;
    int fileByte = file.getContents().length;
    if(fileByte > 15360){
    msgs.add(new FacesMessage("Too big must be at most 15KB"));
    }
    if (!(file.getContentType().startsWith("image"))) {
       msgs.add(new FacesMessage("not an Image file"));
    }
    if (!msgs.isEmpty()) {
       throw new ValidatorException(msgs);
    }
    }
    }

Add these lines of code in web.xml


    <filter>
        <filter-name>PrimeFaces FileUpload Filter</filter-name>
        <filter-class>org.primefaces.webapp.filter.FileUploadFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>PrimeFaces FileUpload Filter</filter-name>
        <servlet-name>Faces Servlet</servlet-name>
    </filter-mapping>

And Dont Forget to add following jar files in lib folder.

commons-io-X.X  and commons-fileupload-X.X, recommended most recent version.

View.xhtml

    <h:form id="ShowProducts">
    <p:dataTable rowsPerPageTemplate="3,6,9" var="products" paginator="true" rows="3" emptyMessage="Catalog is empty" value="#{productController.bean.products}">
    <p:column headerText="Product Name">
    <p:graphicImage width="80" height="80" value="#{productController.content}">
    <f:param name="id" value="#{products.productId}" />
      </p:graphicImage>
    #{products.productName}
    </p:column>
    </p:dataTable>
    </h:form>