Question

我正在尝试实现链接中指定的http post请求：Click here for the link. 我怎么能用Java做到这一点？

String url = "http://sentiment.vivekn.com/api/text/";
URL obj = new URL(url);
HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", USER_AGENT);
con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");

String urlParameters = "Text to classify";

// Send post request
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();

如何将其修改为发送链接中描述的JSON文本数组并检索结果？

Answer 1

试试这个

public static void main(String args[]) throws Exception{
    URL url = new URL("http://sentiment.vivekn.com/api/batch/");
    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
    connection.setConnectTimeout(5000);//5 secs
    connection.setReadTimeout(5000);//5 secs

    connection.setRequestMethod("POST");
    connection.setDoOutput(true);
    connection.setRequestProperty("Content-Type", "application/json");

    OutputStreamWriter out = new OutputStreamWriter(connection.getOutputStream());  
    out.write(
            "[ " +
            "\"the fox jumps over the lazy dog\"," +
            "\"another thing here\" " +
            "]");
    out.flush();
    out.close();

    int res = connection.getResponseCode();

    System.out.println(res);


    InputStream is = connection.getInputStream();
    BufferedReader br = new BufferedReader(new InputStreamReader(is));
    String line = null;
    while((line = br.readLine() ) != null) {
        System.out.println(line);
    }
    connection.disconnect();

}

Answer 2

更改

String urlParameters = "Text to classify";

到

String urlParameters = "{\"no_of_parameters\":1,\"parameters\":{\"1\":true,\"2\":false,\"3\":true},\"service_ID\":\"BT\",\"useCase_ID\":\"SetIgnitionState\"}"; // It's your JSON-array

Answer 3

首先，我将urlParameters重命名为requestContent。前者非常令人困惑，因为这不是真正的参数。其次，您要么必须手动编码，要么让现有的库为您完成（例如Gson）：

Map<String, Object> request = new LinkedHashMap<String, Object>();
request.put("txt", "Text to classify");
Writer writer = new OutputStreamWriter(con.getOutputStream());
Gson.toJson(request, writer);
writer.close();

同样回到收到回复时：

Map<String, Object> result = Gson.fromJson(new InputStreamReader(con.getInputStream), Map.class);
result.get("result").get("confidence")
... etc

或者您可以为请求和响应创建数据类。

Answer 4

要阅读回复，请添加类似于代码底部的内容：

int responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
    reader = new BufferedReader(new    InputStreamReader(connection.getInputStream()));
    StringBuilder sb = new StringBuilder();
    while ((line = reader.readLine()) != null) {
        sb.append(line+"\n");
    }
}

在此之后，StringBuilder将为您提供处理响应。

要发送JSON请求数据，您需要替换：

String urlParameters = "Text to classify";

使用

String urlParameters = "{\"no_of_parameters\":1,\"parameters\":{\"1\":true,\"2\":false,\"3\":true},\"service_ID\":\"BT\",\"useCase_ID\":\"SetIgnitionState\"}";

注意字符串中嵌入引号前面的\。

更好的方法是使用可以构建JSON文本的库，例如：

JSON in Java

如何使用java发送JSON字符串数组的HTTP post请求？

4 个答案: