java - 如何在Java中将请求有效负载发送到REST API？

我想从以下内容检索JSON数据:
https://git.eclipse.org/r/#/c/11376/

要求网址:https://git.eclipse.org/r/gerrit/rpc/ChangeDetailService
请求方法:POST
请求 header :

Accept:application/json

Content-Type:application/json; charset=UTF-8

请求有效负载:

{"jsonrpc":"2.0","method":"changeDetail","params":[{"id":11376}],"id":1}

我已经尝试过 this answer ，但是我正在获取400 BAD REQUEST。

谁能帮我解决这个问题？

谢谢。

最佳答案

以下代码对我有用。

//escape the double quotes in json string
String payload="{\"jsonrpc\":\"2.0\",\"method\":\"changeDetail\",\"params\":[{\"id\":11376}],\"id\":2}";
String requestUrl="https://git.eclipse.org/r/gerrit/rpc/ChangeDetailService";
sendPostRequest(requestUrl, payload);

方法实现:

public static String sendPostRequest(String requestUrl, String payload) {
    try {
        URL url = new URL(requestUrl);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();

        connection.setDoInput(true);
        connection.setDoOutput(true);
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Accept", "application/json");
        connection.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
        OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream(), "UTF-8");
        writer.write(payload);
        writer.close();
        BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        StringBuffer jsonString = new StringBuffer();
        String line;
        while ((line = br.readLine()) != null) {
                jsonString.append(line);
        }
        br.close();
        connection.disconnect();
        return jsonString.toString();
    } catch (Exception e) {
            throw new RuntimeException(e.getMessage());
    }

}