Spring REST Controller returns JSON with empty data

Question

I have a simple Spring Boot web application. I'm trying to receive some data from server. The Controller returns a collection, but the browser receives empty JSON - the number of curly brackets is equals to the number of objects from server, but its content is empty.

@RestController
public class EmployeeController {

@Autowired
private EmployeeManagerImpl employeeManagerImpl;

    @RequestMapping(path="/employees", method = RequestMethod.GET)
    public Iterable<Employee> getAllEmployees() {
        Iterable<Employee> employeesIterable = employeeManagerImpl.getAllEmployees();
        return employeesIterable;
    }
}

The method fires and a browser shows:

Nothing more in the console. Any ideas?

EDIT: Employee.java

@Entity
public class Employee implements Serializable{

    private static final long serialVersionUID = -1723798766434132067L;

    @Id
    @Getter @Setter 
    @GeneratedValue
    private Long id;

    @Getter @Setter
    @Column(name = "first_name")
    private String firstName;

    @Getter @Setter
    @Column(name = "last_name")
    private String lastName;

    @Getter @Setter
    private BigDecimal salary;

    public Employee(){

    }
}

We need to at least see the code for the POJO. It might be that you don't have any serializable fields. — rorschach, Oct 07 '16 at 10:10
Use ResponseBody with the return type as public @ResponseBody Iterable getAllEmployees() { — KayV, Oct 07 '16 at 10:12
@KaranVerma `@RestController` annotation already takes care of that. — rorschach, Oct 07 '16 at 10:16
As is usually, it started after I asked you there. I removed lombok annotations and added common getters and setters. Now i'm receiving what I wanted. But why it doesn't work with lombok? — Radziasss, Oct 07 '16 at 10:19
Well, there could be numerous possibilities - most probable is that Lombok is not properly configured. Can you call the getters/setters in your code? After building your app are the getters/setters included in the `Employee.class` file? — rorschach, Oct 07 '16 at 11:10
Still getting this issue today. Nothing suggested here worked. Ideas welcome — Chris Neve, Dec 22 '18 at 12:19
basically you need public Getters and Setters in your Entity class. Thats the issue I see here — Jebil, May 30 '19 at 10:47

score 12 · Answer 1 · edited Sep 02 '19 at 16:12

12

I think you should use Lombok as class level instead of field level.

@Entity
@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor    
public class Employee implements Serializable {}

This may solve your problem.

edited Sep 02 '19 at 16:12

T04435

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answered Oct 07 '16 at 14:07

Pedro Tavares

1,119
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I didn't know I can use them at class level. Nice, I will use that, but not in this case... nothing has changed. – Radziasss Oct 10 '16 at 05:29
It worked with Data. Then I switched Data with annotations that it covers: ToString, EqualsAndHashCode, Getter, Setter and RequiredArgsConstructor. It worked. Then I only left Getter and Setter. It also worked... I don't get it at all. There must by something wrong with building project by STS then? – Radziasss Oct 11 '16 at 06:42
Can you build and run from console as it is? – Pedro Tavares Oct 12 '16 at 14:05
1

the `@Getter` and `@Setter` can be replaced with single annotation `@Data` – alltej Dec 22 '17 at 21:17
2

basically you need public Getters and Setters in your Entity class. Thats the issue I see here – Jebil May 30 '19 at 10:46
I had the same issue and I resolved it by adding @Getter to my response dto class. – Matthias Sommer Apr 19 '22 at 09:34

score 0 · Answer 2 · answered Oct 07 '16 at 16:33

0

Do you have a converter in the project that converts JAVA objects to JSON. If not, you need on. Try using Jackson in your project.

Once Jackson jars are imported into the project, the dispatcher servlet should have below:

    <beans:bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
        <beans:property name="messageConverters">
            <beans:list>
                <beans:ref bean="jsonMessageConverter" />
            </beans:list>
        </beans:property>
    </beans:bean>

    <!-- Configure bean to convert JSON to POJO and vice versa -->
    <beans:bean id="jsonMessageConverter"
        class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
    </beans:bean>

answered Oct 07 '16 at 16:33

HARDI

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Spring Boot uses Jackson by default. The problem he experiences about Lombok not generating getters thus the fields are not serialized because Jackson looks for getters. – nurgasemetey Oct 09 '16 at 09:37
@nurgasemetey that is true. This default configuration you are writting about, HARDI, I get for free thanks to spring boot. There's something wrong with lombok getters, I didn't solve this yet. – Radziasss Oct 10 '16 at 05:36
Any solution by now? I just stuck into it. – Yishagerew May 05 '17 at 18:45

score -1 · Answer 3 · answered Oct 07 '16 at 10:33

-1

Try adding @ResponseBody to your REST method's return type declaration in the method signature. That should do it if you're using the standard Spring Boot starter project.

answered Oct 07 '16 at 10:33

Mike Thomsen

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It doesn't change anything. The problem is with lombok annotations - they just doesn't work. But why is that? – Radziasss Oct 07 '16 at 10:54
4

`@RestController` automatically adds `@ResponseBody` annotation to all returns. – nurgasemetey Oct 07 '16 at 11:27

Spring REST Controller returns JSON with empty data

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