JSON POST Request getting exception on server side

I am trying to setup a Spring JPA based REST API. I am using com.fasterxml.jackson.core for processing JSON request and response. In my controller, I have a post request where I basically do create operation. The following is the code that does it:

@Autowired
    CustomerRepository repository;

    @RequestMapping(value = "/postcustomer", method = RequestMethod.POST)
    public void postCustomer(@RequestBody Customer customer) {

        repository.save(new Customer(customer.getFirstName(), customer.getLastName()));
    }

So as you can see, I need to send in my body an object of type customer. I am trying to use postman to test it and the following is the JSON I am sending to the server:

{
    "status": "Done",
    "data": [
        "Customer" : {
            "firstname" : "test",
            "lastname" : "123"
        }
    ]
}

Am I send the request wrong? Since I keep getting an exception saying:

{
"timestamp":1501908753094,
"status":400,
"error":"Bad Request",
"exception":"org.springframework.http.converter.HttpMessageNotReadableException",
"message":"JSON parse error: Unexpected character (':' (code 58)): was expecting comma to separate Array entries; nested exception is com.fasterxml.jackson.core.JsonParseException: Unexpected character (':' (code 58)): was expecting comma to separate Array entries\n at [Source: java.io.PushbackInputStream@6f57265c; line: 4, column: 18]",
"path":"/uzmi/postcustomer"
}

UPDATE: After changing my solution according to the answer, I have this: CustomerCOntroller.java:

import com.test.message.Response;
import com.test.repo.CustomerRepository;    
@RestController
public class CustomerController {    
    @Autowired
    CustomerRepository repository;    
    @RequestMapping(value = "/postcustomer", method = RequestMethod.POST)
    public void postCustomer(@RequestBody Response request) {
        request.getData().forEach((data) -> {
            repository.save(data.getCustomer());
        });
    }    
}

Response.java:

package com.test.message;    
import java.io.Serializable;
import java.util.List;    
public class Response implements Serializable {    
    private String status;    
    private List<Data> data;    
    public Response(String status, List<Data> data) {
        this.status = status;
        this.data = data;
    }    
    public Response() {
    }    
    public String getStatus() {
        return status;
    }    
    public void setStatus(String status) {
        this.status = status;
    }    
    public List<Data> getData() {
        return data;
    }    
    public void setData(List<Data> data) {
        this.data = data;
    }    
}

Data.java:

package com.test.message;    
import com.fasterxml.jackson.annotation.JsonProperty;
import com.test.model.Customer;    
public class Data {    
    @JsonProperty("Customer")
    private Customer customer;    
    public Customer getCustomer() {
        return customer;
    }    
    public void setCustomer(Customer customer) {
        this.customer = customer;
    }
    public Data() {
    }
    public Data(Customer customer) {
        this.customer = customer;
    }
}

But now when I try the postcontroller api using the following JSON:

{
    "status": "Done",
    "data": [ {
        "Customer": {
            "firstname" : "test",
            "lastname" : "123"
        }
    }]
}

I get the following error:

{
    "timestamp": 1502014916458,
    "status": 400,
    "error": "Bad Request",
    "exception": "org.springframework.http.converter.HttpMessageNotReadableException",
    "message": "JSON parse error: Can not construct instance of com.test.message.Response: no suitable constructor found, can not deserialize from Object value (missing default constructor or creator, or perhaps need to add/enable type information?); nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not construct instance of com.test.message.Response: no suitable constructor found, can not deserialize from Object value (missing default constructor or creator, or perhaps need to add/enable type information?)\n at [Source: java.io.PushbackInputStream@157f2538; line: 2, column: 5]",
    "path": "/test/postcustomer"
}

UPDATE2: customer.java:

package com.test.model;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "customer")
public class Customer implements Serializable {
    private static final long serialVersionUID = -3009157732242241606L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    @Column(name = "firstname")
    private String firstName;
    @Column(name = "lastname")
    private String lastName;
    protected Customer() {
    }
    public long getId() {
        return id;
    }
    public void setId(long 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;
    }
    public Customer(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }
}

Any ideas where I am going wrong?