Java POJO中两种不同类型的响应
我正在使用Java POJO中两种不同类型的响应,java,json,gson,pojo,json-deserialization,Java,Json,Gson,Pojo,Json Deserialization,我正在使用改造和POJO,这通常是有效的,但是根据结果是否有效,答案有两个不同的对象。哪一个是字符串,另一个是对象: { "data":"No results." } 或: 我的班级: public class Exame { @SerializedName("data") @Expose @Nullable private ExameItem exameItem; private String mensagem; public Ex
改造和POJO
,这通常是有效的,但是根据结果是否有效,答案有两个不同的对象。哪一个是字符串
,另一个是对象
:
{
"data":"No results."
}
或:
我的班级:
public class Exame {
@SerializedName("data")
@Expose
@Nullable
private ExameItem exameItem;
private String mensagem;
public ExameItem getExameItem() {
return exameItem;
}
public void setExameItem(ExameItem exameItem) {
this.exameItem = exameItem;
}
public String getMensagem() {
return mensagem;
}
public void setMensagem(String mensagem) {
this.mensagem = mensagem;
}
}
当我执行Exame().getexamitem
时,它很好,但当我尝试测试Exame()中是否有消息。getMessagem
它会给我带来以下错误:
java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 10 path $.data
所以,我想我该如何测试@data是否是对象的字符串,但我不知道该怎么做,任何人都可以帮忙吗 您需要通过实现JsonDeserializer
接口来实现自定义反序列化程序。请参见以下示例:
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.google.gson.annotations.JsonAdapter;
import java.io.File;
import java.io.FileReader;
import java.lang.reflect.Type;
import java.util.List;
public class GsonApp {
public static void main(String[] args) throws Exception {
File jsonFile = new File("./resource/test.json").getAbsoluteFile();
Gson gson = new GsonBuilder().create();
System.out.println(gson.fromJson(new FileReader(jsonFile), Exame.class));
}
}
class ExamsJsonDeserializer implements JsonDeserializer<Exame> {
@Override
public Exame deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
JsonObject root = json.getAsJsonObject();
JsonElement data = root.get("data");
Exame exam = new Exame();
if (data.isJsonPrimitive()) {
exam.setMensagem(data.getAsString());
} else {
ExameItem examItem = context.deserialize(data, ExameItem.class);
exam.setExameItem(examItem);
}
return exam;
}
}
@JsonAdapter(ExamsJsonDeserializer.class)
class Exame {
private ExameItem exameItem;
private String mensagem;
// getters, setters, toString
}
class ExameItem {
private List<Item> exame;
//getters, setters, toString
}
class Item {
private int id;
// ...
//getters, setters, toString
}
import com.google.gson.gson;
导入com.google.gson.GsonBuilder;
导入com.google.gson.JsonDeserializationContext;
导入com.google.gson.JsonDeserializer;
导入com.google.gson.JsonElement;
导入com.google.gson.JsonObject;
导入com.google.gson.JsonParseException;
导入com.google.gson.annotations.JsonAdapter;
导入java.io.File;
导入java.io.FileReader;
导入java.lang.reflect.Type;
导入java.util.List;
公共类GsonApp{
公共静态void main(字符串[]args)引发异常{
File jsonFile=新文件(“./resource/test.json”).getAbsoluteFile();
Gson Gson=new GsonBuilder().create();
System.out.println(gson.fromJson(新文件读取器(jsonFile),Exame.class));
}
}
类ExamsJsonDeserializer实现JsonDeserializer{
@凌驾
public Exame反序列化(JsonElement json,类型typeOfT,JsonDeserializationContext)引发JsonParseException{
JsonObject root=json.getAsJsonObject();
JsonElement data=root.get(“数据”);
Exame考试=新Exame();
if(data.isJsonPrimitive()){
setmensage(data.getAsString());
}否则{
ExameItem examItem=context.deserialize(数据,ExameItem.class);
考试。设置考试项目(examItem);
}
复试;
}
}
@JsonAdapter(ExamsJsonDeserializer.class)
课堂考试{
私人考试;
私人字符串管理;
//接球手、二传手、投球手
}
课堂考试{
私人清单考试;
//接球手、二传手、投球手
}
类项目{
私有int-id;
// ...
//接球手、二传手、投球手
}
查看此项
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.google.gson.annotations.JsonAdapter;
import java.io.File;
import java.io.FileReader;
import java.lang.reflect.Type;
import java.util.List;
public class GsonApp {
public static void main(String[] args) throws Exception {
File jsonFile = new File("./resource/test.json").getAbsoluteFile();
Gson gson = new GsonBuilder().create();
System.out.println(gson.fromJson(new FileReader(jsonFile), Exame.class));
}
}
class ExamsJsonDeserializer implements JsonDeserializer<Exame> {
@Override
public Exame deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
JsonObject root = json.getAsJsonObject();
JsonElement data = root.get("data");
Exame exam = new Exame();
if (data.isJsonPrimitive()) {
exam.setMensagem(data.getAsString());
} else {
ExameItem examItem = context.deserialize(data, ExameItem.class);
exam.setExameItem(examItem);
}
return exam;
}
}
@JsonAdapter(ExamsJsonDeserializer.class)
class Exame {
private ExameItem exameItem;
private String mensagem;
// getters, setters, toString
}
class ExameItem {
private List<Item> exame;
//getters, setters, toString
}
class Item {
private int id;
// ...
//getters, setters, toString
}