我正在尝试登录用户,并且我正在使用 Retrofit2 进行网络连接,但尽管我已经在邮递员中测试了 API 并且它在那里显示响应但无法在我的应用程序中获取响应,但我从服务器获得了空响应。我无法发现此错误的原因。
这是一个 API 网址。您可以在 email=digi@gmail.com 和 password=digi1234 处查看回复:
http://www.gurgaonhomeo.in/api_server/login
以下是我的堆栈跟踪:
<块引用>java.lang.NullPointerException: 尝试在空对象引用上调用接口方法“java.lang.Object java.util.List.get(int)”
这是我的 api 响应:
{
"data": [
{
"id": "7",
"username": null,
"mobile": "1254785698",
"email": "digi@gmail.com",
"image": "https://example.com",
"created_date": "2020-11-06",
"password": "dasdad324adad245435sffs34535",
"name": "Digi",
"address": "Hsbdbshbd",
"homoeo_practioner": "Yes"
}
],
"status": true,
"code": 200
}
我使用过的这些库:
implementation 'com.squareup.retrofit2:retrofit:2.5.0'
implementation 'com.squareup.retrofit2:converter-gson:2.5.0'
LoginRespose.java
public class LoginResponse {
@Expose
@SerializedName("code")
private String code;
@Expose
@SerializedName("data")
private List<LoginRes> data;
@Expose
@SerializedName("status")
private String status;
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
public List<LoginRes> getData() {
return data;
}
public void setData(List<LoginRes> data) {
this.data = data;
}
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
}
LoginRes.java
public class LoginRes {
@SerializedName("address")
@Expose
private String address;
@SerializedName("created_date")
@Expose
private String createdDate;
@SerializedName("email")
@Expose
private String email;
@SerializedName("homoeo_practioner")
@Expose
private String homoeoPractioner;
@SerializedName("id")
@Expose
private String id;
@SerializedName("image")
@Expose
private String image;
@SerializedName("mobile")
@Expose
private String mobile;
@SerializedName("name")
@Expose
private String name;
@SerializedName("password")
@Expose
private String password;
@SerializedName("username")
@Expose
private String username;
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getCreatedDate() {
return createdDate;
}
public void setCreatedDate(String createdDate) {
this.createdDate = createdDate;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getHomoeoPractioner() {
return homoeoPractioner;
}
public void setHomoeoPractioner(String homoeoPractioner) {
this.homoeoPractioner = homoeoPractioner;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getImage() {
return image;
}
public void setImage(String image) {
this.image = image;
}
public String getMobile() {
return mobile;
}
public void setMobile(String mobile) {
this.mobile = mobile;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
}
ApiService.java
@POST("login")
@FormUrlEncoded
Call<LoginResponse> logUser(@Field("email") String email,
@Field("password") String password);
登录.java
private void go(String mail,String pwd){
Retrofit retrofit = RetrofitClient.getInstance();
ApiService apiService = retrofit.create(ApiService.class);
apiService.logUser(mail,pwd).enqueue(new Callback<LoginResponse>() {
@Override
public void onResponse(Call<LoginResponse> call, Response<LoginResponse> response) {
if(response.isSuccessful()){
prg.dismiss();
List<LoginRes> res = response.body().getData();
Toast.makeText(getApplicationContext(),res.get(0).getEmail(),Toast.LENGTH_SHORT).show();
}
}
@Override
public void onFailure(Call<LoginResponse> call, Throwable t) {
prg.dismiss();
Toast.makeText(getApplicationContext(),t.getMessage(),Toast.LENGTH_SHORT).show();
}
});
}
为什么我从服务器得到空响应?
答案 0 :(得分:0)
首先检查 response.body() 是否为空。然后检查 data 内部响应是否为空或 []。然后,如果满足了这些要求,那么就拿清单并举杯祝酒。