import java.io.*; import java.text.*; import java.util.*; /** * An encapsulation of an HTTP response * * This version: * * Only supports two header elements, Content-Type and Content-Length * * @author Prof. David Bernstein, James Madison University * @version 0.0 */ public class HttpResponse { private byte[] data; private int contentLength, status; private NumberFormat nf; private String contentType; public static final int SC_ACCEPTED = 202; public static final int SC_BAD_GATEWAY = 502; public static final int SC_BAD_REQUEST = 400; public static final int SC_CREATED = 201; public static final int SC_FORBIDDEN = 403; public static final int SC_INTERNAL_ERROR = 500; public static final int SC_MOVED = 301; public static final int SC_NO_RESPONSE = 204; public static final int SC_NOT_FOUND = 404; public static final int SC_NOT_IMPLEMENTED = 501; public static final int SC_OK = 200; public static final int SC_PARTIAL_INFORMATION = 203; public static final int SC_PAYMENT_REQUIRED = 402; public static final int SC_SERVICE_OVERLOADED = 503; public static final int SC_UNAUTHORIZED = 401; /** * Default Constructor * */ public HttpResponse() { nf = NumberFormat.getIntegerInstance(); status = SC_OK; data = null; } /** * Get the default message associated with a status code * * @param sc The status code * @return The associated default message */ public static String getStatusMessage(int sc) { switch (sc) { case SC_ACCEPTED: return "Accepted"; case SC_BAD_GATEWAY: return "Bad Gateway"; case SC_BAD_REQUEST: return "Bad Request"; case SC_CREATED: return "Created"; case SC_FORBIDDEN: return "Forbidden"; case SC_INTERNAL_ERROR: return "Internal Error"; case SC_MOVED: return "Moved"; case SC_NO_RESPONSE: return "No Response"; case SC_NOT_FOUND: return "Not Found"; case SC_NOT_IMPLEMENTED: return "Not Implemented"; case SC_OK: return "OK"; case SC_PARTIAL_INFORMATION: return "Partial Information"; case SC_PAYMENT_REQUIRED: return "Payment Required"; case SC_SERVICE_OVERLOADED: return "Service Overloaded"; case SC_UNAUTHORIZED: return "Unauthorized"; default: return "Unknown Status Code " + sc; } } /** * Send an error response to the client. * * After using this method, the response should be considered to * be committed and should not be written to. * * @param sc The status code * @param out The HttpOutputStream to write to */ public void sendError(int sc, HttpOutputStream out) { String errorHTML; errorHTML = "

HTTP Error "+ sc + " - " + getStatusMessage(sc)+ "

\r\n"; setStatus(sc); setData(errorHTML.getBytes()); try { write(out); } catch (IOException ioe) { // Nothing can be done } } /** * Sets the status code for this response * * @param sc The status code */ public void setStatus(int sc) { status = sc; } /** * Sets the length of the content the server returns to the client * * @param length The length (in bytes) */ public void setContentLength(int length) { contentLength = length; } /** * Sets the type of the content the server returns to the client * * @param type The type */ public void setContentType(String type) { contentType = type; } /** * Set the payload/data for this HttpResponse * * @param data The payload/data */ public void setData(byte[] data) { this.data = data; } /** * Write this HttpResponse * * @param out The HttpOutputStream to write to */ public void write(HttpOutputStream out) throws IOException { if (data != null) setContentLength(data.length); else setContentLength(0); writeStatusLine(out); writeHeaders(out); if (data != null) out.write(data); out.flush(); out.close(); } /** * Write the headers to an output stream * * @param out The HttpOutputStream to write to */ private void writeHeaders(HttpOutputStream out) { boolean hasHeaders; Enumeration e; out.printHeaderLine("Content-Length", String.valueOf(contentLength)); out.printHeaderLine("Content-Type", contentType); out.printEOL(); out.flush(); } /** * Write the status line to an output stream * * @param out The HttpOutputStream to write to */ private void writeStatusLine(HttpOutputStream out) { out.print("HTTP/1.0"); out.print(" "); nf.setMaximumIntegerDigits(3); nf.setMinimumIntegerDigits(3); out.print(nf.format(status)); out.print(" "); out.print(getStatusMessage(status)); out.printEOL(); out.flush(); } }