Java 将类转换为 JSONObject
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Convert class into a JSONObject
提问by TTransmit
I have several classes like this. I want to convert the classes into JSONObject format.
我有好几个这样的课。我想将类转换为 JSONObject 格式。
import java.io.Serializable;
import com.google.gson.annotations.SerializedName;
public class User implements Serializable {
private static final long serialVersionUID = 1L;
@SerializedName("id")
private Integer mId;
@SerializedName("name")
private String mName = "";
@SerializedName("email")
private String mEmail;
public Integer getId() {
return mId;
}
public void setId(Integer id) {
mId = id;
}
public String getName() {
return mName;
}
public void setName(String name) {
mName = name;
}
public String getEmail() {
return mEmail;
}
public void setEmail(String email) {
mEmail = email;
}
}
I know that I can convert these classes to JSONObject format as follows:
我知道我可以将这些类转换为 JSONObject 格式，如下所示：
User user = new User();
JSONObject jsonObj = new JSONObject();
try {
jsonObj.put("id", user.getId());
jsonObj.put("name", user.getName());
jsonObj.put("email", user.getEmail());
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
The problem is that I need to do this for a lot of different classes that are much longer than this across a lot of files. Can I use GSON to fill the JSONObject from myClass so that I don't need to edit every time the class structure changes?
问题是我需要为许多不同的类执行此操作，这些类在很多文件中都比这长得多。我可以使用 GSON 来填充 myClass 中的 JSONObject 以便每次类结构更改时都不需要进行编辑吗？
The following returns a JSON string but I need it as an Object as when I send it to the system that sends the requests via a REST API it sends with unwanted quotation marks.
以下返回一个 JSON 字符串，但我需要它作为一个对象，因为当我将它发送到通过 REST API 发送请求的系统时，它使用不需要的引号发送。
User user = new User();
Gson gson = new Gson();
Object request = gson.toJson(user);
When I use this in another JSON builder that asks for an Object I get
当我在另一个请求对象的 JSON 构建器中使用它时，我得到
{"request":"{"id":"100","name":"Test Name","email":"[email protected]"}"}
When I want
当我想要
{"request":{"id":"100","name":"Test Name","email":"[email protected]"}}
回答by Patrick M
Here is a crude example you can use to use Reflection to build the JSONObject..
这是一个粗略的示例，您可以使用反射来构建 JSONObject..
Warning it's not pretty and does not contain really type-safety.
警告它不漂亮并且不包含真正的类型安全。
public static JSONObject quickParse(Object obj) throws IllegalArgumentException, IllegalAccessException, JSONException{
JSONObject object = new JSONObject();
Class<?> objClass = obj.getClass();
Field[] fields = objClass.getDeclaredFields();
for(Field field : fields) {
field.setAccessible(true);
Annotation[] annotations = field.getDeclaredAnnotations();
for(Annotation annotation : annotations){
if(annotation instanceof SerializedName){
SerializedName myAnnotation = (SerializedName) annotation;
String name = myAnnotation.value();
Object value = field.get(obj);
if(value == null)
value = new String("");
object.put(name, value);
}
}
}
return object;
}
Here is an example usage:
这是一个示例用法：
User user = new User();
JSONObject obj = quickParse(user);
System.out.println(obj.toString(3));
Output
输出
{
"id": "",
"name": "",
"email": ""
}
回答by TTransmit
I found that the following works with GSON:
我发现以下适用于 GSON：
User = new User();
Gson gson = new Gson();
String jsonString = gson.toJson(user);
try {
JSONObject request = new JSONObject(jsonString);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
This is not type safe, however.
然而，这不是类型安全的。
