Question

我试图通过POST从Java提交表单。我想发送一些值并将它们存储在Web服务器上的sql db中。我在堆栈上找到了这个例子，但我不理解它。

URL是否应该引用接受POST请求的php文件？我必须考虑其他值。我的gessss是好的，他们应该匹配我的PHP文件的POST检查。

这是否需要成功地将带有POST的数据从Java发送到我的网络服务器？

URL url = new URL("http://g.php");
        Map<String,Object> params = new LinkedHashMap<>();
        params.put("value", 5);
        params.put("id", 17);

        StringBuilder postData = new StringBuilder();
        for (Map.Entry<String,Object> param : params.entrySet()) {
            if (postData.length() != 0) postData.append('&');
            postData.append(URLEncoder.encode(param.getKey(), "UTF-8"));
            postData.append('=');
            postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
        }
        byte[] postDataBytes = postData.toString().getBytes("UTF-8");

        HttpURLConnection conn = (HttpURLConnection)url.openConnection();
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        conn.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length));
        conn.setDoOutput(true);
        conn.getOutputStream().write(postDataBytes);

        Reader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));

        for (int c; (c = in.read()) >= 0;)
            System.out.print((char)c);

Answer 1

相同，但注释：

    URL url = new URL("http://g.php"); // URL to your application
    Map<String,Object> params = new LinkedHashMap<>();
    params.put("value", 5); // All parameters, also easy
    params.put("id", 17);

    StringBuilder postData = new StringBuilder();
    // POST as urlencoded is basically key-value pairs, as with GET
    // This creates key=value&key=value&... pairs
    for (Map.Entry<String,Object> param : params.entrySet()) {
        if (postData.length() != 0) postData.append('&');
        postData.append(URLEncoder.encode(param.getKey(), "UTF-8"));
        postData.append('=');
        postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
    }

    // Convert string to byte array, as it should be sent
    byte[] postDataBytes = postData.toString().getBytes("UTF-8");

    // Connect, easy
    HttpURLConnection conn = (HttpURLConnection)url.openConnection();
    // Tell server that this is POST and in which format is the data
    conn.setRequestMethod("POST");
    conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
    conn.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length));
    conn.setDoOutput(true);
    conn.getOutputStream().write(postDataBytes);

    // This gets the output from your server
    Reader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));

    for (int c; (c = in.read()) >= 0;)
        System.out.print((char)c);

Answer 2

以下示例对我有用

HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("http://example.com/");
// Request parameters and other properties.
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("user", "Bob"));
try {
    httpPost.setEntity(new UrlEncodedFormEntity(params, "UTF-8"));
} catch (UnsupportedEncodingException e) {
    // writing error to Log
    e.printStackTrace();
}

使用Java发送POST数据

2 个答案: