CODEWITHSUNDEEP
javajsfdependency-injectionjsf-2
Rahul Shivsharan
Rahul Shivsharan

Reputation: 2561

Unable to inject Datasource in Managed Bean

Hi i am trying to load list of Students onload of a Page in JSF using h:datatable tag

<h:dataTable value="#{studentBean2.studentList}" var="student">
  ......
  .....
</h:datatable>

now my ManagedBean is as follows

public class StudentBeanTwo {
     public StudentBeanTwo() {
         init();
     }

@Resource(name="jdbc/rahul_sample_pool",type=DataSource.class)
private  DataSource dataSource; 

private void init(){
    .......
    ....... 
    if(this.getStudentList() == null){
       loadStudents();              
    }   
}

private void loadStudents() throws Exception{
    Connection con = null;
    .....
    .....
    try{

       if(this.dataSource == null){
          System.out.println(" DataSource() is null  ");
       }
       con = this.dataSource.getConnection();
       ........
    }
}

now my Question is why my datasource is null,

i check by annotating @Resource to a variable in another servlet an i am able to create the connection,

so whats the problem in the above managed-bean,

why datasource is null ? The container is not able to inject Resource, why ?

please help me out

Upvotes: 1

Views: 1944

Answers (1)

Matt Handy
Matt Handy

Reputation: 30025

In addition to Björns comment: Injection is done after construction and you call your init method from the constructor.

You could annotate your init() method with @PostConstruct. Then it will be called after construction and not during construction.

import javax.annotation.PostConstruct;
...
    @PostConstruct
    private void init(){
        ...
        if(this.getStudentList() == null){
           loadStudents();              
        }   
    }

Then the init method gets called every time the bean is constructed (depending on your bean's scope).

Upvotes: 4

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