[英]Json structure to get data with a GET method android studio retrofit java
我收到一个错误:预期为BEGIN_ARRAY,但在第1行第2列路径处为BEGIN_OBJECT $我所了解的是,翻新需要BEGIN_ARRAY吗? 我找到了一些解决方案,但对我不起作用。
我尝试了一些无效的解决方案。 我认为这是我不知道如何使用它的JSON结构。
所以对于我的代码:我的界面
public interface UserService {
String ENDPOINT = "http://localhost:3000/";
@GET("users")
Call<List<User>> getUsers();
}
资料
public class User {
@SerializedName("_id")
@Expose
private int _id;
@SerializedName("name")
@Expose
private String name;
@SerializedName("firstname")
@Expose
private String firstname;
@SerializedName("picture")
@Expose
private String picture;
public int getId() {
return _id;
}
public String getName() {
return name;
}
public String getFirstname() {
return firstname;
}
public String getPicture() {
return picture;
}
}
我的主要活动
textViewResult = findViewById(R.id.text_view_result);
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(UserService.ENDPOINT)
.addConverterFactory(GsonConverterFactory.create())
.build();
UserService jsonUserService = retrofit.create(UserService.class);
Call<List<User>> call = jsonUserService.getUsers();
call.enqueue(new Callback<List<User>>() {
@Override
public void onResponse(Call<List<User>> call, Response<List<User>> response) {
if(!response.isSuccessful()){
textViewResult.setText("Code : " + response.code());
return;
}
List<User> users = response.body();
for(User user : users){
String content = "";
content += "ID: " + user.getId() + '\n';
content += "FirstName: " + user.getFirstname() + '\n';
content += "Name: " + user.getName() + '\n';
content += "Picture: " + user.getPicture() + '\n';
textViewResult.append(content);
}
}
@Override
public void onFailure(Call<List<User>> call, Throwable t) {
textViewResult.setText(t.getMessage());
}
});
我的json看起来像..
{
"users": [
{
"_id": 1,
"name": "test",
"firstname": "user",
"picture": "http://localhost:3000/imgs/1.jpg"
},
{
"_id": 2,
"name": "test1",
"firstname": "user1",
"picture": "http://localhost:3000/imgs/2.jpg"
},
{
"_id": 3,
"name": "test2",
"firstname": "user2",
"picture": "http://localhost:3000/imgs/3.jpg"
},
}
我认为是“用户”:导致了此问题。 但是我不知道如何解决这个问题。
非常感谢任何人有解决方案。
您的回应等级应该是
class APIResponse{
@SerializedName("users")
@Expose
private List<User> users;
public List<User> getUsers()
{return users;}
public void setUsers(List<User> users)
{this.users= users;}
}
接口应该是;
public interface UserService {
String ENDPOINT = "http://localhost:3000/";
@GET("users")
Call<APIResponse> getUsers();
}
您的enqueue()方法应为:
call.enqueue(new Callback<APIResponse>() {
@Override
public void onResponse(Call<APIResponse> call, Response<APIResponse> response) {
if(!response.isSuccessful()){
textViewResult.setText("Code : " + response.code());
return;
}
List<User> users = response.body().getUsers();
for(User user : users){
String content = "";
content += "ID: " + user.getId() + '\n';
content += "FirstName: " + user.getFirstname() + '\n';
content += "Name: " + user.getName() + '\n';
content += "Picture: " + user.getPicture() + '\n';
textViewResult.append(content);
}
}
@Override
public void onFailure(Call<List<User>> call, Throwable t) {
textViewResult.setText(t.getMessage());
}
});
您的Response(即您的情况下的User类)存在问题,这就是显示此错误的原因。
将您的数据类(User.java)更改为ResponseClass.java ::
public class ResponseClass {
@SerializedName("users")
@Expose
private List<User> users = null;
public List<User> getUsers() {
return users;
}
public void setUsers(List<User> users) {
this.users = users;
}
public class User {
@SerializedName("_id")
@Expose
private Integer id;
@SerializedName("name")
@Expose
private String name;
@SerializedName("firstname")
@Expose
private String firstname;
@SerializedName("picture")
@Expose
private String picture;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getFirstname() {
return firstname;
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
public String getPicture() {
return picture;
}
public void setPicture(String picture) {
this.picture = picture;
}
}
@Rajasekaran
我的另一个问题是:
public class User {
@SerializedName("_id")
@Expose
private int _id;
@SerializedName("name")
@Expose
private String name;
@SerializedName("firstname")
@Expose
private String firstname;
@SerializedName("picture")
@Expose
private String picture;
//Getters
}
public class APIResponse {
@SerializedName("users")
@Expose
private List<User> users = null;
public List<User> getUsers()
{return users;}
public void setUsers(List<User> users)
{this.users= users;}
}
这是我的MainActivity
UserService jsonUserService = retrofit.create(UserService.class);
Call<List<APIResponse>> call = jsonUserService.getUsers();
call.enqueue(new Callback<List<APIResponse>>() {
@Override
public void onResponse(Call<List<APIResponse>> call, Response<List<APIResponse>> response) {
if(!response.isSuccessful()){
textViewResult.setText("Code : " + response.code());
return;
}
List<User> listUser = null;
List<APIResponse> users = response.body();
for(APIResponse user : users){
listUSer = user.getUsers();
}
for(User user : listUser){
String content = "";
content += "ID: " + user.getId() + '\n';
content += "FirstName: " + user.getFirstname() + '\n';
content += "Name: " + user.getName() + '\n';
content += "Picture: " + user.getPicture() + '\n';
textViewResult.append(content);
}
Log.e("MainActivity", "Success : " + listUser);
}
@Override
public void onFailure(Call<List<APIResponse>> call, Throwable t) {
Log.e("MainActivity", "Failure : " + t);
}
});
2019-05-22 14:05:07.983 18425-18425 / com.example.user E / MainActivity:故障:java.lang.IllegalStateException:预期BEGIN_ARRAY但在第1行第2列路径处为BEGIN_OBJECT $
我有同样的错误:(
非常感谢 !
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