POST 请求发送 JSON 数据 Java HttpUrlConnection [英] POST request send JSON data Java HttpUrlConnection

问题描述

我开发了一个 Java 代码，可以使用 URL 和 HttpUrlConnection 将以下 cURL 转换为 Java 代码.卷曲是:

I have developed a Java code that convert the following cURL to java code using URL and HttpUrlConnection. the cURL is :

curl -i 'http://url.com' -X POST -H "Content-Type: application/json" -H "Accept: application/json" -d '{"auth": { "passwordCredentials": {"username": "adm", "password": "pwd"},"tenantName":"adm"}}'

我已经编写了这段代码，但它总是给出 HTTP 代码 400 错误请求.我找不到丢失的东西.

I have written this code but it always gives HTTP code 400 bad request. I couldn't find what is missing.

String url="http://url.com";
URL object=new URL(url);

HttpURLConnection con = (HttpURLConnection) object.openConnection();
con.setDoOutput(true);
con.setDoInput(true);
con.setRequestProperty("Content-Type", "application/json");
con.setRequestProperty("Accept", "application/json");
con.setRequestMethod("POST");

JSONObject cred   = new JSONObject();
JSONObject auth   = new JSONObject();
JSONObject parent = new JSONObject();

cred.put("username","adm");
cred.put("password", "pwd");

auth.put("tenantName", "adm");
auth.put("passwordCredentials", cred.toString());

parent.put("auth", auth.toString());

OutputStreamWriter wr = new OutputStreamWriter(con.getOutputStream());
wr.write(parent.toString());
wr.flush();

//display what returns the POST request

StringBuilder sb = new StringBuilder();  
int HttpResult = con.getResponseCode(); 
if (HttpResult == HttpURLConnection.HTTP_OK) {
    BufferedReader br = new BufferedReader(
            new InputStreamReader(con.getInputStream(), "utf-8"));
    String line = null;  
    while ((line = br.readLine()) != null) {  
        sb.append(line + "
");  
    }
    br.close();
    System.out.println("" + sb.toString());  
} else {
    System.out.println(con.getResponseMessage());  
}  

推荐答案

您的 JSON 不正确.而不是

Your JSON is not correct. Instead of

JSONObject cred = new JSONObject();
JSONObject auth=new JSONObject();
JSONObject parent=new JSONObject();
cred.put("username","adm");
cred.put("password", "pwd");
auth.put("tenantName", "adm");
auth.put("passwordCredentials", cred.toString()); // <-- toString()
parent.put("auth", auth.toString());              // <-- toString()

OutputStreamWriter wr= new OutputStreamWriter(con.getOutputStream());
wr.write(parent.toString());

写

JSONObject cred = new JSONObject();
JSONObject auth=new JSONObject();
JSONObject parent=new JSONObject();
cred.put("username","adm");
cred.put("password", "pwd");
auth.put("tenantName", "adm");
auth.put("passwordCredentials", cred);
parent.put("auth", auth);

OutputStreamWriter wr= new OutputStreamWriter(con.getOutputStream());
wr.write(parent.toString());

因此，对于外部对象，JSONObject.toString() 应该只调用一次.

So, the JSONObject.toString() should be called only once for the outer object.

另一件事(很可能不是你的问题，但我想提一下):

Another thing (most probably not your problem, but I'd like to mention it):

为确保不会遇到编码问题，您应该指定编码，如果不是UTF-8:

To be sure not to run into encoding problems, you should specify the encoding, if it is not UTF-8:

con.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
con.setRequestProperty("Accept", "application/json");

// ...

OutputStream os = con.getOutputStream();
os.write(parent.toString().getBytes("UTF-8"));
os.close();

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