我有以下Json字符串，我想要反序列化。问题是：由于这个字符串来自服务器，我无法改变它，我需要反序列化为POJO。您可以看到Grafs键对每个子区域具有不同的值。一个是对象，另一个是数组。我怎么处理这个？
{
"Status": "true",
"Result: {
"rows": {
"row": {
"status": true,
"subareas": [
{
"nome": "Associacao Utente",
"id": 9,
"grafs": {
"rows": {
"id": 6,
"nome": "Associacao Utente",
"tipo": "PIE",
"serv": "MV_AS_UTENTE_POR_NEGOCIO",
"periodo": "ANO"
}
}
}, {
"nome": "Chaves",
"id": 60,
"grafs": {
"rows": [
{
"id": 35,
"nome": "Chaves Criados por ano",
"tipo": "LINHA",
"serv": "MV_ASSOC_TOTAL_CHAVES",
"periodo": "ANO"
}, {
"id": 592,
"nome": "Chaves Associado Ao User Portal",
"tipo": "BAR",
"serv": "MV_ASSOC_USER_CHAVES",
"periodo": "TODOS"
}, {
"id": 593,
"nome": "Chaves Associado Ao Negocios",
"tipo": "BAR",
"serv": "MV_ASSOC_CHAVES",
"periodo": "TODOS"
}
]
}
}
]
}
}
}
}
以下是我的课程。
public class Example {
private String Status;
private Result Result;
public String getStatus() {
return Status;
}
public void setStatus(String status) {
Status = status;
}
public Result getResult() {
return Result;
}
public void setResult(Result result) {
Result = result;
}
@Override
public String toString() {
return "Example [Status=" + Status + ", Result=" + Result + "]";
}
}
public class Result {
private Rows rows;
public Rows getRows() {
return rows;
}
public void setRows(Rows rows) {
this.rows = rows;
}
@Override
public String toString() {
return "Result [rows=" + rows + "]";
}
}
public class Grafs {
private List<Rows_> rows = new ArrayList<>();
public List<Rows_> getRows() {
return rows;
}
public void setRows(List<Rows_> Rows) {
this.rows = Rows;
}
@Override
public String toString() {
return "Grafs [rows=" + rows + "]";
}
}
public class Row {
private Boolean status;
private List<Subarea> subareas = new ArrayList<>();
public Boolean getStatus() {
return status;
}
public void setStatus(Boolean status) {
this.status = status;
}
public List<Subarea> getSubareas() {
return subareas;
}
public void setSubareas(List<Subarea> subareas) {
this.subareas = subareas;
}
@Override
public String toString() {
return "Row [status=" + status + ", subareas=" + subareas + "]";
}
}
public class Row_ {
private Integer id;
private String nome;
private String serv;
private String periodo;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getNome() {
return nome;
}
public void setNome(String nome) {
this.nome = nome;
}
public String getServ() {
return serv;
}
public void setServ(String serv) {
this.serv = serv;
}
public String getPeriodo() {
return periodo;
}
public void setPeriodo(String periodo) {
this.periodo = periodo;
}
@Override
public String toString() {
return "Row_ [id=" + id + ", nome=" + nome + ", serv=" + serv
+ ", periodo=" + periodo + "]";
}
}
public class Rows {
private Row row;
public Row getRow() {
return row;
}
public void setRow(Row row) {
this.row = row;
}
@Override
public String toString() {
return "Rows [row=" + row + "]";
}
}
public class Rows_ {
private Row_ row;
public Row_ getRow() {
return row;
}
public void setRow(Row_ row) {
this.row = row;
}
}
public class Subarea {
private String nome;
private Integer id;
private Grafs grafs;
public String getNome() {
return nome;
}
public void setNome(String nome) {
this.nome = nome;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public Grafs getGrafs() {
return grafs;
}
public void setGrafs(Grafs grafs) {
this.grafs = grafs;
}
@Override
public String toString() {
return "Subarea [nome=" + nome + ", id=" + id + ", grafs=" + grafs
+ "]";
}
}
使用这些类我收到以下错误：
Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 13 column 18.
我将Rows_声明为arraylist并且遇到了一个对象。但第二个Rows_确实是一个阵列。我该如何解决这个问题？
具有一个元素的数组仍应呈现为数组。这就是我使用数组的原因。但是它给出了我描述的错误。
感谢您的帮助。我真的很感激。
答案 0 :(得分：1)
您可以使用TypeAdapterFactory进行转换。这是一个将该功能添加到所有List成员类型的工厂 -
import com.google.gson.Gson;
import com.google.gson.TypeAdapter;
import com.google.gson.TypeAdapterFactory;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.JsonWriter;
import java.io.IOException;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Collections;
import java.util.List;
public class SingletonListTypeAdapterFactory implements TypeAdapterFactory {
public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
Type type = typeToken.getType();
if (typeToken.getRawType() != List.class
|| !(type instanceof ParameterizedType)) {
return null;
}
Type elementType = ((ParameterizedType) type).getActualTypeArguments()[0];
TypeAdapter<?> elementAdapter = gson.getAdapter(TypeToken.get(elementType));
TypeAdapter<T> arrayAdapter = gson.getDelegateAdapter(this, typeToken);
return (TypeAdapter<T>) newSingtonListAdapter((TypeAdapter<Object>) elementAdapter, (TypeAdapter<List<Object>>) arrayAdapter);
}
private <E> TypeAdapter<List<E>> newSingtonListAdapter(
final TypeAdapter<E> elementAdapter,
final TypeAdapter<List<E>> arrayAdapter) {
return new TypeAdapter<List<E>>() {
public void write(JsonWriter out, List<E> value) throws IOException {
if(value == null || value.isEmpty()) {
out.nullValue();
} else if(value.size() == 1) {
elementAdapter.write(out, value.get(0));
} else {
arrayAdapter.write(out, value);
}
}
public List<E> read(JsonReader in) throws IOException {
if (in.peek() != JsonToken.BEGIN_ARRAY) {
E obj = elementAdapter.read(in);
return Collections.singletonList(obj);
}
return arrayAdapter.read(in);
}
};
}
}
作为奖励，如果需要，它也会以相同的方式序列化。如果您还想序列化为数组，请通过调用write替换arrayAdapter.write方法。
给你，在建设时加入你的gson -
Gson gson = new GsonBuilder().registerTypeAdapterFactory(new SingletonListTypeAdapterFactory())
.create();