Java Gson：直接将String转换为JsonObject（无POJO）
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Gson: Directly convert String to JsonObject (no POJO)
提问by 7zark7
Can't seem to figure this out.
I'm attempting JSON tree manipulation in GSON, but I have a case where I do not know or have a POJO to convert a string into, prior to converting to JsonObject. Is there a way to go directly from a Stringto JsonObject?
似乎无法弄清楚这一点。我正在 GSON 中尝试 JSON 树操作，但是在转换为JsonObject. 有没有办法直接从 aString转到JsonObject？
I've tried the following (Scala syntax):
我尝试了以下（Scala 语法）：
val gson = (new GsonBuilder).create
val a: JsonObject = gson.toJsonTree("""{ "a": "A", "b": true }""").getAsJsonObject
val b: JsonObject = gson.fromJson("""{ "a": "A", "b": true }""", classOf[JsonObject])
but afails, the JSON is escaped and parsed as a JsonStringonly, and
breturns an empty JsonObject.
但a失败了，JSON 被转义并解析为JsonStringonly，并
b返回一个空的JsonObject。
Any ideas?
有任何想法吗？
采纳答案by Dallan Quass
use JsonParser; for example:
使用 JsonParser；例如：
JsonParser parser = new JsonParser();
JsonObject o = parser.parse("{\"a\": \"A\"}").getAsJsonObject();
回答by Dan Menes
Just encountered the same problem. You can write a trivial custom deserializer for the JsonElementclass:
刚遇到同样的问题。您可以为JsonElement该类编写一个简单的自定义反序列化器：
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
GsonBuilder gson_builder = new GsonBuilder();
gson_builder.registerTypeAdapter(
JsonElement.class,
new JsonDeserializer<JsonElement>() {
@Override
public JsonElement deserialize(JsonElement arg0,
Type arg1,
JsonDeserializationContext arg2)
throws JsonParseException {
return arg0;
}
} );
String str = "{ \"a\": \"A\", \"b\": true }";
Gson gson = gson_builder.create();
JsonElement element = gson.fromJson(str, JsonElement.class);
JsonObject object = element.getAsJsonObject();
回答by maverick
Try to use getAsJsonObject()instead of a straight cast used in the accepted answer:
尝试使用getAsJsonObject()而不是接受的答案中使用的直接转换：
JsonObject o = new JsonParser().parse("{\"a\": \"A\"}").getAsJsonObject();
回答by Purushotham
String jsonStr = "{\"a\": \"A\"}";
Gson gson = new Gson();
JsonElement element = gson.fromJson (jsonStr, JsonElement.class);
JsonObject jsonObj = element.getAsJsonObject();
回答by c2willi
Came across a scenario with remote sorting of data store in EXTJS 4.X where the string is sent to the server as a JSON array (of only 1 object).
Similar approach to what is presented previously for a simple string, just need conversion to JsonArray first prior to JsonObject.
在 EXTJS 4.X 中遇到了远程排序数据存储的场景，其中字符串作为 JSON 数组（只有 1 个对象）发送到服务器。
类似于之前为简单字符串提供的方法，只需要在 JsonObject 之前先转换为 JsonArray。
String from client: [{"property":"COLUMN_NAME","direction":"ASC"}]
来自客户端的字符串：[{"property":"COLUMN_NAME","direction":"ASC"}]
String jsonIn = "[{\"property\":\"COLUMN_NAME\",\"direction\":\"ASC\"}]";
JsonArray o = (JsonArray)new JsonParser().parse(jsonIn);
String sortColumn = o.get(0).getAsJsonObject().get("property").getAsString());
String sortDirection = o.get(0).getAsJsonObject().get("direction").getAsString());
回答by Jozef Benikovsky
The simplest way is to use the JsonPrimitiveclass, which derives from JsonElement, as shown below:
最简单的方法是使用JsonPrimitive派生自的类，JsonElement如下所示：
JsonElement element = new JsonPrimitive(yourString);
JsonObject result = element.getAsJsonObject();
回答by Eduardo Chico
I believe this is a more easy approach:
我相信这是一种更简单的方法：
public class HibernateProxyTypeAdapter implements JsonSerializer<HibernateProxy>{
public JsonElement serialize(HibernateProxy object_,
Type type_,
JsonSerializationContext context_) {
return new GsonBuilder().create().toJsonTree(initializeAndUnproxy(object_)).getAsJsonObject();
// that will convert enum object to its ordinal value and convert it to json element
}
public static <T> T initializeAndUnproxy(T entity) {
if (entity == null) {
throw new
NullPointerException("Entity passed for initialization is null");
}
Hibernate.initialize(entity);
if (entity instanceof HibernateProxy) {
entity = (T) ((HibernateProxy) entity).getHibernateLazyInitializer()
.getImplementation();
}
return entity;
}
}
And then you will be able to call it like this:
然后你就可以这样调用它：
Gson gson = new GsonBuilder()
.registerTypeHierarchyAdapter(HibernateProxy.class, new HibernateProxyTypeAdapter())
.create();
This way all the hibernate objects will be converted automatically.
这样所有的休眠对象都将自动转换。
回答by Maddy
//import com.google.gson.JsonObject;
JsonObject complaint = new JsonObject();
complaint.addProperty("key", "value");
回答by Stephen Paul
The JsonParserconstructor has been deprecated. Use the static method instead:
该JsonParser构造已被弃用。改用静态方法：
JsonObject asJsonObject = JsonParser.parseString(request.schema).getAsJsonObject();
