使用HttpURLConnection提交json POST請求

我想在Scala中使用HttpURLConnection提交json發佈請求。我跟着跟着兩個教程和生產這樣的：使用HttpURLConnection提交json POST請求

def sendPost(url: String, jsonHash: String) { 
    val conn: HttpURLConnection = new URL(url).openConnection().asInstanceOf[HttpURLConnection] 
    conn.setRequestMethod("POST") 
    conn.setRequestProperty("Content-Type", "application/json") 
    conn.setRequestProperty("Accept", "application/json") 
    conn.setDoOutput(true) 
    conn.connect() 

    val wr = new DataOutputStream(conn.getOutputStream) 
    wr.writeBytes(jsonHash) 
    wr.flush() 
    wr.close() 

    val responseCode = conn.getResponseCode 

    println("Sent: " + jsonHash + " to " + url + " received " + responseCode) 

    val in = new BufferedReader(new InputStreamReader(conn.getInputStream)) 
    var response: String = "" 
    while(response != null) { 
    response = in.readLine() 
    println(response) 
    } 
    in.close() 
}

它與迴應：

Sent: '{"schedule":"R/2014-02-02T00:00:00Z/PT24H", "name":"Scala-Post-Test", "command":"which scalac", "epsilon":"PT15M", "owner":"[email protected]", "async":false}' to http://localhost:4040/scheduler/iso8601 received 500 

java.io.IOException: Server returned HTTP response code: 500 for URL: http://localhost:4040/scheduler/iso8601

從

val in = new BufferedReader(new InputStreamReader(conn.getInputStream))

制止，但如果我重建爲curl請求時，它工作正常：

curl -X POST -H 'Content-Type: application/json' -d '{"schedule":"R/2014-02-02T00:00:00Z/PT24H", "name":"Scala-Post-Test", "command":"which scalac", "epsilon":"PT15M", "owner":"[email protected]", "async":false}' http://localhost:4040/scheduler/iso8601 

requirement failed: Vertex already exists in graph Scala-Post-Test

（這是我期望的）

任何洞察到什麼是錯的？我正在嘗試嗅探數據包以確定不同之處。

（注：我以前在sys.process._放棄）

來源

2014-01-21 Austin

使用'PrintWriter'（而不是'DataOutputStream'）。 –

^^暫時忽略它。雖然這裏通常不使用'DataOutputStream'，但在這種情況下沒有任何區別。當你輸出'jsonHash'字符串時，它顯示你的JSON被單引號括起來;這可能是問題。 –

啊哈！你是正確的，單引號導致500. - 或許，nc -l現在看起來是一樣的，但400錯誤請求。搜索仍在繼續。 – Austin

問題就在這裏：

Sent: '{"schedule":"R/2014-02-02T00:00:00Z/PT24H", "name":"Scala-Post-Test", "command":"which scalac", "epsilon":"PT15M", "owner":"[email protected]", "async":false}' to http://localhost:4040/scheduler/iso8601 received 500

你會注意到你的JSON由單引號包圍。這使它無效。

另外值得注意的是，雖然此代碼工作，您正在使用DataOutputStream.writeBytes()輸出您的數據。如果您的字符串包含任何內容但不包含單字節字符，則這會造成問題;它會從每個char中去除高8位（Java使用2字節的字符來保存UTF-16碼點）。

最好使用更適合String輸出的東西。用於輸入的相同技術，例如：

BufferedWriter out = 
    new BufferedWriter(new OutputStreamWriter(conn.getOutputStream)); 
out.write(jsonString); 
out.close();

來源

2014-01-21 23:36:39

使用HttpURLConnection提交json POST請求

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