我想保存来自一个api的json响应的参数，以便移交给另一个api。另一个api应该接收帐户余额，并说明客户是否有正余额或负余额。
json码：

id:        1
name:      "Lars"
lastname:  "Günther"
birth:     "1995-10-10"
sex:       "m"
road:      "Bahnhofsstrasse 17"
town:      "Borken"
account:    

 0: 
    bankaccNr:        3
    customerstatus:   "private client"
    accountbalance:   -3127
    openingdate:      "2001-01-23"
    iban:             "DE37500105174133576347"

 1: 
    bankaccNr:        16
    customerstatus:   "corporate client"
    accountbalance:   71764
    openingdate:      "2014-07-09"
    iban:             "DE09500105177725527397"

postalcode: 46325

这就是我调用这个api时得到的json。0和1不是模型的一部分。当此帐户Map到客户时，它们将自动生成。
客户：

@ManyToMany(targetEntity = Account.class, mappedBy = "customer", cascade = CascadeType.ALL)
private Set<Account> account= new HashSet<>();

public Customer() {}

public Customer(String name, String lastname, Date birth, char sex, String road, int postalcode, String town) {
    this.name=name;
    this.lastname=lastname;
    this.birth=birth;
    this.sex=sex;
    this.road=road;
    this.postalcode=postalcode;
    this.town=town;         
}
//getters/setters...

我应该将它保存为对象还是哈希Map。如何处理此对象？如果一个客户有多个帐户怎么办？

@RequestMapping(value = { "/{id}/liquid" }, method = RequestMethod.GET)
public Konto getLiquid(@PathVariable(value = "id") Long customer_id){   

    String url = "http://localhost:8081/mybank/customer/data/{id}";
    Customer customer= restTemplate.getForObject(url, Kunde.class,kundeid);
    'object or hashmap?' 
    HashMap <String,Map> answer= restTemplate.getForObject(url, new HashMap<>().getClass(),kundeid);

    String urlForServiceB = "http://localhost:8082/liquicontroller/liquiditat/{value}";

    int firstvalue = ???
    // get http response --> true or false
    return restTemplate.getForObject(urlForServiceB, String.class,firstvalue);
}

如何向其他api发送多个请求？