java - 获取 JSON 响应时获取 411 响应代码

Question

在我的应用程序中，我尝试使用 POST 请求获取响应。响应服务器以 Json 格式发送给我。但是在添加属性之后，它返回给我的响应代码为 411(即内容长度问题)。我已经添加了内容长度。那么我没有得到的问题在哪里。这是我的代码:

String url = "https://xxx:8243/people/v3";
STRURL = url + HttpComm.getConnectionString().trim();

StringBuffer postData = new StringBuffer();
HttpConnection httpConnection = null;
try {
    httpConnection = (HttpConnection) Connector.open(STRURL);
} catch (IOException e1) {
    e1.printStackTrace();
};

try {
    httpConnection.setRequestMethod("POST");
    postData.append("?username="+user);
    postData.append("&password="+password);
    String encodedData = postData.toString();
    byte[] postDataByte = postData.toString().getBytes("UTF-8");
    httpConnection.setRequestProperty("Authorization", "bearer"+"ZWOu3HL4vwaOLrFAuEFqsxNQf6ka");
    httpConnection.setRequestProperty("Content-Type","application/json");
    httpConnection.setRequestProperty("Content-Length", String.valueOf(postDataByte.length));
    OutputStream out = httpConnection.openOutputStream();
    DataOutputStream dos = new DataOutputStream(out);
    out.write(postData.toString().getBytes());
    out.flush();
    int statusCode = httpConnection.getResponseCode();
    Logger.out("HttpComm", "status code:::::::   "+statusCode);
    if (statusCode != HttpConnection.HTTP_OK)
    {

    }

更新代码:

HttpConnection httpConnection = null;
    try {
        httpConnection = (HttpConnection) Connector.open(STRURL);
    } catch (IOException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    };
            try {
                httpConnection.setRequestMethod("POST");
                URLEncodedPostData postData = new URLEncodedPostData("UTF-8", false);
                 postData.append("username", user);
                 postData.append("password", password);
                 byte[] postDataByte = postData.getBytes();
                  httpConnection.setRequestProperty("Authorization", "bearer"+"ZWOu3HL4vwaOLrFAuEFqsxNQf6ka");
                   httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
                   httpConnection.setRequestProperty("Content-Length", String.valueOf(postDataByte.length));
                   OutputStream out = httpConnection.openOutputStream(); 
                   out.write(postDataByte);
                   out.flush();

                   int statusCode = httpConnection.getResponseCode();
                   Logger.out("HttpComm", "status code:::::::   "+statusCode);

Answer 1

有些地方看起来不太对劲。我会推荐尝试这个:

 httpConnection.setRequestMethod("POST");

 URLEncodedPostData postData = new URLEncodedPostData("UTF-8", false);
 postData.append("username", user);
 postData.append("password", password);
 byte[] postDataByte = postData.getBytes();

 httpConnection.setRequestProperty("Authorization", "bearer"+"ZWOu3HL4vwaOLrFAuEFqsxNQf6ka");
 httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
 httpConnection.setRequestProperty("Content-Length", String.valueOf(postDataByte.length));

 OutputStream out = httpConnection.openOutputStream(); 
 DataOutputStream dos = new DataOutputStream(out);
 out.write(postDataByte);
 out.flush();

 int statusCode = httpConnection.getResponseCode();
 Logger.out("HttpComm", "status code:::::::   "+statusCode);
 if (statusCode != HttpConnection.HTTP_OK)

我改变了什么:

1. 正如@samlewis 所说，代码正在创建一个变量来保存发布的数据字节，但在调用 out.write() 时并未使用它。

2. 代码将内容类型设置为 JSON，但它并未发送 JSON。该请求只是两个参数。响应可能是 JSON，但您没有在请求的 Content-Type 参数中指定它。

3. 用户名/密码参数仅使用字符串进行编码。通常，最好使用 URLEncodedPostData类 to hold your POST parameters .

4. 如果你打算使用字符串，我认为在用户名参数的前面添加一个 ? 仍然是不正确的。如果您想在 GET URL 中对参数进行编码，则可以使用 https://xxx:8243/people/v3?username=user&password=password。但是，这段代码使用的是 POST，而不是 GET。

5. 还有一个未使用的 encodedData 变量。