Java 映射到 JSON 到 Typescript 映射
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Java Map to JSON to Typescript Map
提问by Androidicus
on my server side I have a Java object that contains a HashMap. I want to serialize it to JSON, return it to my Angular2 client and use it as a Map/Dictionary there.
在我的服务器端，我有一个包含 HashMap 的 Java 对象。我想将它序列化为 JSON，将它返回给我的 Angular2 客户端并将其用作 Map/Dictionary 那里。
Here's the class:
这是课程：
public class FileUploadResult {
String timestamp;
String message;
String status;
HashMap<String, String> parameters;
public FileUploadResult(String status, String message, String timestamp, HashMap parameters) {
this.status = status;
this.message = message;
this.timestamp = timestamp;
this.parameters = parameters;
}
}
}
Here's the JSON that I receive on the client side:
这是我在客户端收到的 JSON：
{"timestamp":"","message":"Test","status":"1","parameters":{"myKey":"Value","mySecondKey":"Another Value"}}
Here's my receiving Angular2 http call:
这是我收到的 Angular2 http 调用：
this.http.post(this.uploadURL, formData).map((res:Response) => res.json() as FileUploadResult).catch(this.handleError);
FileUploadResult on the client looks like this:
客户端上的 FileUploadResult 如下所示：
export class FileUploadResult {
status: string;
timestamp: string;
message: string;
parameters: Map<string, string>;
constructor() {
this.parameters = new Map<string, string>();
}
addParameter(key: string, value: string) {
this.parameters.set(key, value);
}
getParameters() {
return this.parameters;
}
}
By using the "as FileUploadResult" in the http.map call, I expected to get an object on where I can call result.getParameters().get("myKey"). But that's not happening. I get an unspecified object where the only call that works is result.parameters.myKey. Is there a way to achieve what I want and to cast the JSON object to the FileUploadResult including the Angular2 map?
通过在 http.map 调用中使用“as FileUploadResult”，我希望在我可以调用的地方获得一个对象result.getParameters().get("myKey")。但事实并非如此。我得到一个未指定的对象，其中唯一有效的调用是result.parameters.myKey. 有没有办法实现我想要的并将 JSON 对象转换为 FileUploadResult 包括 Angular2 地图？
回答by Nitzan Tomer
The result of calling res.json()is a javascript object which can be accessed like so:
调用的结果res.json()是一个可以像这样访问的 javascript 对象：
let json = res.json();
console.log(json["timestamp"]);
console.log(json.message);
The way to describe such an object in typescript is using an interface (or type alias):
在打字稿中描述此类对象的方法是使用接口（或类型别名）：
interface JsonResponse {
timestamp: string;
message: string;
status: string;
parameters: { [name: string]: string };
}
If you want to transform this object into your class you'll need to do something like:
如果您想将此对象转换为您的类，您需要执行以下操作：
class FileUploadResult {
status: string;
timestamp: string;
message: string;
parameters: Map<string, string>;
constructor(json: JsonResponse) {
this.status = json.status;
this.timestamp = json.timestamp;
this.message = json.message;
this.parameters = new Map<string, string>();
Object.keys(json.parameters).forEach(key => {
this.addParameter(key, json.parameters[key]);
});
}
addParameter(key: string, value: string) {
this.parameters.set(key, value);
}
getParameters() {
return this.parameters;
}
}
（操场上的代码）
