在敲代码之前,我们需要了解正常的FormData表单提交究竟向服务器提交了哪些内容。
首先使用postman向本地socket服务器发送FormData表单,postman示例如下:
socket服务端收到的内容如下:
127.0.0.1:11787
Data Request : POST / HTTP/1.1
User-Agent: PostmanRuntime/7.19.0
Accept: */*
Cache-Control: no-cache
Postman-Token: 067860f8-4295-493a-a597-184d22b3e247
Host: localhost:8080
Content-Type: multipart/form-data; boundary=--------------------------926274221155642082481101
Accept-Encoding: gzip, deflate
Cookie: JSESSIONID=ED0FA7D018270E8CF75AA978B36EAEDE
Content-Length: 262
Connection: keep-alive
----------------------------926274221155642082481101
Content-Disposition: form-data; name="12"
34
----------------------------926274221155642082481101
Content-Disposition: form-data; name="56"
78
----------------------------926274221155642082481101--
再使用postman发送text数据,示例如下:
socket服务端收到的数据如下:
127.0.0.1:11933
Data Request : POST / HTTP/1.1
User-Agent: PostmanRuntime/7.19.0
Accept: */*
Cache-Control: no-cache
Postman-Token: d3356b13-b5e0-47b8-973a-c8ff7cc39d88
Host: localhost:8080
Accept-Encoding: gzip, deflate
Content-Length: 3
Cookie: JSESSIONID=ED0FA7D018270E8CF75AA978B36EAEDE
Connection: keep-alive
123
通过对比我们可以得出,相比较text、xml及json数据,formdata表单只是在发送信息的格式和头信息中有特定的要求,其余并无任何差异,主要集中在“boundary”参数上。
具体代码如下:
public String postFormData(String path, HashMap<String, String> Headers, HashMap<String, String> formMap) {
String result = "";
HttpURLConnection connection = null;
String boundary = "--------------------------132183525382215881770481";
try {
URL url = new URL(path);
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setRequestProperty("Connection", "Keep-Alive");
// 不使用缓存
connection.setUseCaches(false);
if (Headers != null) {
if (Headers.size() > 0) {
for (Map.Entry<String, String> entry : Headers.entrySet()) {
connection.setRequestProperty(entry.getKey(), entry.getValue());
}
}
}
StringBuffer formSB = new StringBuffer();
if (formMap != null) {
if (formMap.size() > 0) {
for (Map.Entry<String, String> entry : formMap.entrySet()) {
String inputName = entry.getKey();
String inputValue = entry.getValue();
formSB.append("\r\n").append("--").append(boundary).append("\r\n");
formSB.append("Content-Disposition: form-data; name=\"" + inputName + "\"\r\n\r\n");
formSB.append(inputValue);
}
formSB.append("\r\n").append("--").append(boundary).append("--");
}
}
connection.connect();
//OutputStream out = new DataOutputStream(connection.getOutputStream());
PrintWriter out = new PrintWriter(new OutputStreamWriter(connection.getOutputStream(), "UTF-8"));
out.print(formSB.toString());
out.flush();
//获得响应状态
int resultCode = connection.getResponseCode();
if (HttpURLConnection.HTTP_OK == resultCode) {
formSB = new StringBuffer();
String readLine;
BufferedReader responseReader = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
while ((readLine = responseReader.readLine()) != null) {
formSB.append(readLine).append("\n");
}
responseReader.close();
result = formSB.toString();
} else {
result = "{\"code\":\"" + resultCode + "\"}";
}
out.close();
} catch (Exception e) {
logger.error(e.toString());
return "{\"code\":500,\"result\":\"" + "POST表单请求 " + path + " 时出现异常\"}";
} finally {
connection.disconnect();
}
return result;
}