使用JSweet将地图显示为JSON(Post Map as JSON using JSweet)

使用JSweet将地图显示为JSON(Post Map as JSON using JSweet)

我想从客户端发送一个java.util.HashMap转换为JSON到服务器。

我使用JSweet为客户端将Java转换为JavaScript。

我看了一下XMLHttpRequest并试图使用JSON.stringify(new HashMap<>())来准备传输映射，但是这导致了

TypeError：循环对象值

在客户端。

这些是我的相关依赖项（使用Gradle）：

// Java to JavaScript transpilation compile "org.jsweet:jsweet-transpiler:1.2.0-SNAPSHOT" compile "org.jsweet.candies:jsweet-core:1.1.1" // Allows us to use Java features like Optional or Collections in client code compile "org.jsweet.candies:j4ts:0.2.0-SNAPSHOT"

I'd like to send a java.util.HashMap converted to JSON from the client to the server.

I'm using JSweet to transpile Java to JavaScript for the client side.

I had a look at XMLHttpRequest and tried to prepare the map for transfer using JSON.stringify(new HashMap<>()) but this resulted in a

TypeError: cyclic object value

on the client side.

These are my relevant dependencies (using Gradle):

// Java to JavaScript transpilation compile "org.jsweet:jsweet-transpiler:1.2.0-SNAPSHOT" compile "org.jsweet.candies:jsweet-core:1.1.1" // Allows us to use Java features like Optional or Collections in client code compile "org.jsweet.candies:j4ts:0.2.0-SNAPSHOT"

最满意答案

我必须将java.util.Map转换为jsweet.lang.Object然后使用stringify将其编码为JSON。

以下是使用JSweet将java.util.Map作为JSON发送到服务器的代码：

void postJson(Map<String, String> map, String url) { XMLHttpRequest request = new XMLHttpRequest(); // Post asynchronously request.open("POST", url, true); request.setRequestHeader("Content-Type", "application/json;charset=UTF-8"); // Encode the data as JSON before sending String mapAsJson = JSON.stringify(toJsObject(map)); request.send(mapAsJson); } jsweet.lang.Object toJsObject(Map<String, String> map) { jsweet.lang.Object jsObject = new jsweet.lang.Object(); // Put the keys and values from the map into the object for (Entry<String, String> keyVal : map.entrySet()) { jsObject.$set(keyVal.getKey(), keyVal.getValue()); } return jsObject; }

像这样使用它：

Map<String, String> message = new HashMap<>(); message.put("content", "client says hi"); postJson(message, "http://myServer:8080/newMessage");

I had to convert the java.util.Map to a jsweet.lang.Object before encoding it as JSON using stringify.

Here's the code to send a java.util.Map as JSON to the server using JSweet:

void postJson(Map<String, String> map, String url) { XMLHttpRequest request = new XMLHttpRequest(); // Post asynchronously request.open("POST", url, true); request.setRequestHeader("Content-Type", "application/json;charset=UTF-8"); // Encode the data as JSON before sending String mapAsJson = JSON.stringify(toJsObject(map)); request.send(mapAsJson); } jsweet.lang.Object toJsObject(Map<String, String> map) { jsweet.lang.Object jsObject = new jsweet.lang.Object(); // Put the keys and values from the map into the object for (Entry<String, String> keyVal : map.entrySet()) { jsObject.$set(keyVal.getKey(), keyVal.getValue()); } return jsObject; }

Use it like this:

Map<String, String> message = new HashMap<>(); message.put("content", "client says hi"); postJson(message, "http://myServer:8080/newMessage");