问题
i try to write simplest possible server app in Java, displaying html form with textarea input, which after submitting gives me possibility to parse xml typed in that textarea. For now i build simple serversocket based server like that:
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class WebServer {
protected void start() {
ServerSocket s;
String gets = "";
System.out.println("Start on port 80");
try {
// create the main server socket
s = new ServerSocket(80);
} catch (Exception e) {
System.out.println("Error: " + e);
return;
}
System.out.println("Waiting for connection");
for (;;) {
try {
// wait for a connection
Socket remote = s.accept();
// remote is now the connected socket
System.out.println("Connection, sending data.");
BufferedReader in = new BufferedReader(new InputStreamReader(
remote.getInputStream()));
PrintWriter out = new PrintWriter(remote.getOutputStream());
String str = ".";
while (!str.equals("")) {
str = in.readLine();
if (str.contains("GET")){
gets = str;
break;
}
}
out.println("HTTP/1.0 200 OK");
out.println("Content-Type: text/html");
out.println("");
// Send the HTML page
String method = "get";
out.print("<html><form method="+method+">");
out.print("<textarea name=we></textarea></br>");
out.print("<input type=text name=a><input type=submit></form></html>");
out.println(gets);
out.flush();
remote.close();
} catch (Exception e) {
System.out.println("Error: " + e);
}
}
}
public static void main(String args[]) {
WebServer ws = new WebServer();
ws.start();
}
}
After form (textarea with xml and one additional text input) is submitted in 'gets' String-type variable I have Urlencoded values of my variables (also displayed on the screen, it looks like that:
gets = GET /?we=%3Cnetwork+ip_addr%3D%2210.0.0.0%2F8%22+save_ip%3D%22true%22%3E%0D%0A%3Csubnet+interf_used%3D%22200%22+name%3D%22lan1%22+%2F%3E%0D%0A%3Csubnet+interf_used%3D%22254%22+name%3D%22lan2%22+%2F%3E%0D%0A%3C%2Fnetwork%3E&a=fooBar HTTP/1.1
What can i do to change GET to POST method (if i simply change it in form and than put " if (str.contains("POST")){" it gives me string like
gets = POST / HTTP/1.1
with no variables. And after that, how i can use xml from my textarea field (called 'we')?
回答1:
As there is a blank line following the headers, here is my relatively simple way of getting the post payload data, after having read the header information using the readLine() method of BufferedReader.
//socket is an instance of Socket
InputStream is = socket.getInputStream();
InputStreamReader isReader = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isReader);
//code to read and print headers
String headerLine = null;
while((headerLine = br.readLine()).length() != 0){
System.out.println(headerLine);
}
//code to read the post payload data
StringBuilder payload = new StringBuilder();
while(br.ready()){
payload.append((char) br.read());
}
System.out.println("Payload data is: "+payload.toString())
回答2:
This is my implementation for read POST body:
try {
Socket socket = params[0];
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
BufferedWriter out = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
// read request
String line;
line = in.readLine();
StringBuilder raw = new StringBuilder();
raw.append("" + line);
boolean isPost = line.startsWith("POST");
int contentLength = 0;
while (!(line = in.readLine()).equals("")) {
raw.append('\n' + line);
if (isPost) {
final String contentHeader = "Content-Length: ";
if (line.startsWith(contentHeader)) {
contentLength = Integer.parseInt(line.substring(contentHeader.length()));
}
}
}
StringBuilder body = new StringBuilder();
if (isPost) {
int c = 0;
for (int i = 0; i < contentLength; i++) {
c = in.read();
body.append((char) c);
Log.d("JCD", "POST: " + ((char) c) + " " + c);
}
}
raw.append(body.toString());
publishProgress(raw.toString());
// send response
out.write("HTTP/1.1 200 OK\r\n");
out.write("Content-Type: text/html\r\n");
out.write("\r\n");
out.write(new Date().toString());
if (isPost) {
out.write("<br><u>" + body.toString() + "</u>");
} else {
out.write("<form method='POST'>");
out.write("<input name='name' type='text'/>");
out.write("<input type='submit'/>");
out.write("</form>");
}
//
// do not in.close();
out.flush();
out.close();
socket.close();
//
} catch (Exception e) {
e.printStackTrace();
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
publishProgress('\n' + sw.toString());
}
I do it for android and publishProgres in my case means:
protected void onProgressUpdate(String... values) {
super.onProgressUpdate(values);
instance.logTextView.append(values[0]);
}
回答3:
A typical HTTP POST request looks like this:
POST / HTTP/1.1
Host: www.example.com
Accept: text/html,*/*;q=0.5
User-Agent: BrowserName/1.0
Referer: http://www.example.com/
Content-type: application/x-www-form-urlencoded; charset=utf-8
foo=1&bar=2
The first line contains the method (typically GET or POST, but there's more, like HEAD, PUT, DELETE), the request URI, and the protocol version. Then there are a number of request headers, which may not be so important for a simple server. If the method is one that takes a request body (POST and PUT), then after the headers there's a blank line followed by the request body. In the case of a POST from an HTML form, the body will consists of key=value pairs for all form elements, joined by &. The values will be %-encoded.
You just need to take care of properly parsing the entire request.
You should be aware that line endings in HTTP are supposed to be Windows-style (\r\n). The readline() method might interpret this as two linebreaks, so it might look like there's an empty line between each of the real lines.
回答4:
POST data is not in the first line. Print all lines and you'll see. It's actually immediately after a blank line.
回答5:
From this -
We need to first read headers and then read again from the same BufferedReader using actual content length provided in the header section :-
BufferedReader in = new BufferedReader(new InputStreamReader(is));
String line;
line = in.readLine();
while ((line = in.readLine()) != null && (line.length() != 0)) {
System.out.println("HTTP-HEADER: " + line);
if (line.indexOf("Content-Length:") > -1) {
postDataI = new Integer(
line.substring(
line.indexOf("Content-Length:") + 16,
line.length())).intValue();
}
}
String postData = "";
// read the post data
if (postDataI > 0) {
char[] charArray = new char[postDataI];
in.read(charArray, 0, postDataI);
postData = new String(charArray);
}
HTH
来源：https://stackoverflow.com/questions/3033755/reading-post-data-from-html-form-sent-to-serversocket