如何使用JSON数据（java）发送POST方法？

我需要使用JSON数据发送POST方法，确保我需要将序列化的JSON对象发送到字符串中。 不是JSON字符串本身。所以我如何使用JAVA实现它

Answer 1

public static String sendPostRequest(String postURL) throws Exception{ String responseStr=null; //make POST request String jsonContent = "{'name': 'newIndia','columns': [{'name': 'Species','type': 'STRING'}],'description': 'Insect Tracking Information.','isExportable': true}"; //String data = "{\"document\" : {\"_id\": \"" + id+ "\", \"context\":" + context +"}}"; URL url = new URL(postURL); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.setDoOutput(true); connection.setDoInput(true); connection.setInstanceFollowRedirects(false); connection.setRequestMethod("POST"); connection.setRequestProperty("Content-Type", "application/json"); connection.setRequestProperty("charset", "utf-8"); connection.setRequestProperty("Content-Length", "" + Integer.toString(jsonContent.getBytes().length)); connection.setUseCaches(false); OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream(), "UTF-8"); writer.write(jsonContent); writer.close(); responseStr="Response code: "+connection.getResponseCode()+" and mesg:"+connection.getResponseMessage(); System.out.println(connection.getResponseMessage()); InputStream response; // Check for error , if none store response if(connection.getResponseCode() == 200){ response = connection.getInputStream(); }else{ response = connection.getErrorStream(); } InputStreamReader isr = new InputStreamReader(response); StringBuilder sb = new StringBuilder(); BufferedReader br = new BufferedReader(isr); String read = br.readLine(); while(read != null){ sb.append(read); read = br.readLine(); } // Print the String System.out.println(sb.toString()); connection.disconnect(); return responseStr; } 

有关更多信息，请参阅此示例 。

Answer 2

我建议使用Jersey REST框架，它与GAE配合使用。 这是一个演示。

Answer 3

使用gson ，您可以非常轻松地将JSON数据发布到Web服务。

例如：

 public class MyData { //var myJsonData = { private boolean fans = true; // fans:true, private boolean funds = true; // funds:true //private String chart = "day"; // } } 

现在将POJO发送到真正的网络服务：

 public class Main { public static void main(String... args) throws Exception { URL theUrl = new URL("https://robertsspaceindustries.com/api/stats/getCrowdfundStats"); Gson gson = new Gson(); JsonParser jp = new JsonParser(); MyData thedata = new MyData(); HttpsURLConnection urlConnection = (HttpsURLConnection) theUrl.openConnection(); urlConnection.setRequestMethod("POST"); urlConnection.setDoOutput(true); //allow parameters to be sent/appended DataOutputStream wr = new DataOutputStream(urlConnection.getOutputStream()); wr.writeBytes(gson.toJson(thedata)); //convert the POJO to JSON, then to binary. wr.flush(); wr.close(); urlConnection.connect(); //start request transmission JsonElement retJson = jp.parse(new InputStreamReader((InputStream) urlConnection.getContent())); //convert the input stream to a json element System.out.println(retJson.getAsJsonObject()); urlConnection.disconnect(); //end request transmission } } 

回复：

 {"success":1,"{"fans":910125,"funds":8410319141},"code":"OK","msg":"OK"} 

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（注意，写作时的等效cURL命令是） – >

 curl 'https://robertsspaceindustries.com/api/stats/getCrowdfundStats' --data-binary '{"fans":true,"funds":true}'