Question

我尝试用Java编写最简单的服务器应用程序，显示带有textarea输入的html表单，提交后我可以解析在该textarea中键入的xml。现在我构建基于serversocket的简单服务器：

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();
  }
}

在表单（带有xml的textarea和一个额外的文本输入）之后，在'gets'字符串类型变量中提交我的变量的Urlencoded值（也显示在屏幕上，它看起来像：

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

我该怎么做才能将GET更改为POST方法（如果我只是在表单中更改它而不是放“if（str.contains（”POST“））{”它给我字符串

gets = POST / HTTP/1.1

没有变数。之后，我如何使用我的textarea字段中的xml（称为“我们”）？

Answer 1

由于标题后面有一个空行，在使用BufferedReader的readLine()方法读取标题信息之后，这是获取后有效负载数据的相对简单的方法。

//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())

Answer 2

这是我读取POST主体的实现：

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());
}

我是为Android做的，publishProgres在我的情况下意味着：

protected void onProgressUpdate(String... values) {
        super.onProgressUpdate(values);
        instance.logTextView.append(values[0]);
    }

Answer 3

典型的HTTP POST请求如下所示：

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

第一行包含方法（通常是GET或POST，但还有更多，如HEAD，PUT，DELETE），请求URI和协议版本。然后有许多请求标头，这对于简单的服务器可能不那么重要。如果该方法是一个接受请求体（POST和PUT）的方法，那么在标题之后有一个空白行，后跟请求体。对于来自HTML表单的POST，正文将包含key=value对所有表单元素，由&加入。值将为％-encoded。

您只需要妥善解析整个请求。

您应该知道HTTP中的行结尾应该是Windows风格的（\r\n）。 readline()方法可能将此解释为两个换行符，因此看起来每个实际行之间都有一个空行。

Answer 4

POST数据不在第一行。打印所有行，你会看到。它实际上是在一个空白行之后。

Answer 5

来自truncate record -

我们需要首先读取标题，然后使用标题部分中提供的实际内容长度从同一个BufferedReader中再次读取： -

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

从html表单读取POST数据发送到serversocket

5 个答案: