git-svn-id: https://robotics.mvla.net/svn/frc971/2013/trunk/src@4136 f308d9b7-e957-4cde-b6ac-9a88185e7312
diff --git a/971CV/src/org/frc971/HTTPClient.java b/971CV/src/org/frc971/HTTPClient.java
new file mode 100644
index 0000000..294b49f
--- /dev/null
+++ b/971CV/src/org/frc971/HTTPClient.java
@@ -0,0 +1,146 @@
+package org.frc971;
+
+//Author: Daniel Petti
+
+import java.io.*;
+import java.net.*;
+
+import java.awt.image.BufferedImage;
+import javax.imageio.ImageIO;
+
+import com.googlecode.javacv.cpp.opencv_core.IplImage;
+
+public class HTTPClient {
+ //Connects to HTTP Server on robot and receives images
+
+ private final static boolean LOCAL_DEBUG = true;
+
+ private Socket sock;
+ private BufferedReader sock_in;
+ private PrintWriter sock_out;
+
+ private String LastBoundary = "";
+
+ private void WriteDebug(String message) {
+ //small helper function to write debug messages
+ if (LOCAL_DEBUG)
+ System.out.println(message);
+ }
+ private String ReadtoBoundary(String boundary) {
+ //reads from socket until it encounters a specific character combination
+ //if boundary is null, it reads until it runs out of data
+ StringBuilder recvd = new StringBuilder();
+ String message = "";
+ try {
+ sock.setSoTimeout(5000);
+ }
+ catch (SocketException e) {
+ System.err.println("Warning: Could not set socket timeout.");
+ }
+ try {
+ int ret;
+ while ((ret = sock_in.read()) != -1) {
+ if (ret == 0) {
+ //finished receiving
+ message += recvd.toString();
+ recvd.setLength(0);
+ if (boundary == null)
+ break;
+ }
+ else {
+ recvd.append((char)ret);
+ if (boundary != null) {
+ if (message.contains(boundary))
+ break;
+ else
+ continue;
+ }
+ }
+ }
+ }
+ catch (InterruptedIOException e) {
+ System.err.println("Warning: Image receive timed out.");
+ return null;
+ }
+ catch (IOException e) {
+ System.err.println("Error: Socket read failed.");
+ return null;
+ }
+ return message;
+ }
+ public HTTPClient() {
+ //Initialize socket connection to robot
+ try {
+ WriteDebug("Connecting to server...");
+ sock = new Socket("192.168.0.178", 9714);
+ sock_in = new BufferedReader(new InputStreamReader(sock.getInputStream()));
+ sock_out = new PrintWriter(sock.getOutputStream(), true);
+ //Write headers
+ //HTTPStreamer does not actually use the headers, so we can just write terminating chars.
+ WriteDebug("Writing headers...");
+ sock_out.println("\r\n\r\n");
+ //Receive headers
+ WriteDebug("Reading headers...");
+ ReadtoBoundary("cross\r\n");
+ WriteDebug("Now receiving data.");
+ }
+ catch (UnknownHostException e) {
+ System.err.println("Error: Invalid host.");
+ System.exit(1);
+ }
+ catch (IOException e) {
+ System.err.println("Error: Socket IO failed.");
+ System.exit(2);
+ }
+
+ }
+ public ImageWithTimestamp GetFrame() {
+ //read all current data from socket, in case of processing bottleneck
+ WriteDebug("Emptying TCP stack...");
+ String message = ReadtoBoundary(null);
+ //we must end with a boundary
+ int len = message.length();
+ if (message.substring(len - 4, len - 1) != "\r\n\r\n") {
+ WriteDebug("Boundary was not found. Waiting for boundary...");
+ message += ReadtoBoundary("\r\n\r\n");
+ }
+ //Add the last boundary we cut off to the beginning of our message
+ message = LastBoundary + message;
+ //Divide our large message into string separated by boundary beginnings
+ String[] cut = message.split("\r\n--");
+ len = cut.length;
+ //Save the newest boundary, so we can use it later.
+ LastBoundary = cut[len - 1];
+ //Keep only our penultimate boundary and the image after it
+ //NOTE that message is missing its preceding \r\n--
+ message = cut[len - 2];
+ cut = message.split("\r\n\r\n");
+ //NOTE that boundary is now missing its trailing \r\n\r\n
+ String boundary = cut[0];
+ String JPEGImage = cut[1];
+ //extract timestamp in seconds
+ cut = boundary.split("X-Timestamp: ");
+ String time_data = cut[1];
+ boundary = cut[0];
+ float timestamp = Float.parseFloat(time_data);
+ //extract size so we can make sure our image data is not corrupted
+ cut = boundary.split("Content-Length: ");
+ String size_data = cut[1];
+ float size = Float.parseFloat(size_data);
+ assert (size == JPEGImage.length()) : ("Fatal size mismatch between image and expected image size. Check regular expressions.");
+ byte[] ImageArray = JPEGImage.getBytes();
+ InputStream in = new ByteArrayInputStream(ImageArray);
+ try {
+ BufferedImage bImageFromConvert = ImageIO.read(in);
+ ImageWithTimestamp to_return = new ImageWithTimestamp();
+ to_return.image = IplImage.createFrom(bImageFromConvert);
+ to_return.timestamp = timestamp;
+ WriteDebug("Image processing successful.");
+ return to_return;
+ }
+ catch (IOException e) {
+ System.err.println(e.getMessage());
+ return null;
+ }
+ }
+}