Servlets http-status-codes
- 1. SERVLETS - HTTP STATUS CODES http://www.tuto rialspo int.co m/se rvle ts/se rvle ts-http-status-co de s.htm Co pyrig ht © tuto rials po int.c om T he format of the HT T P request and HT T P response messag es are similar and will have following structure: An initial status line + CRLF ( Carriag e Return + Line Feed ie. New Line ) Z ero or more header lines + CRLF A blank line ie. a CRLF An optioanl messag e body like file, query data or query output. For example, a server response header looks as follows: HTTP/1.1 200 OK Content-Type: text/html Header2: ... ... HeaderN: ... (Blank Line) <!doctype ...> <html> <head>...</head> <body> ... </body> </html> T he status line consists of the HT T P version (HT T P/1.1 in the example), a status code (200 in the example), and a very short messag e corresponding to the status code (OK in the example). Following is a list of HT T P status codes and associated messag es that mig ht be returned from the Web Server: Code: Messag e: Desc ription: 100 Continue Only a part of the request has been received by the server, but as long as it has not been rejected, the client should continue with the request 101 Switching Protocols T he server switches protocol. 200 OK T he request is OK 201 Created T he request is complete, and a new resource is created 202 Accepted T he request is accepted for processing , but the processing is not complete. 203 Non-authoritative Information 204 No Content 205 Reset Content 206 Partial Content 300 Multiple Choices A link list. T he user can select a link and g o to that location. Maximum five addresses 301 Moved Permanently T he requested pag e has moved to a new url 302 Found T he requested pag e has moved temporarily to a new url
- 2. 302 Found T he requested pag e has moved temporarily to a new url 303 See Other T he requested pag e can be found under a different url 304 Not Modified 305 Use Proxy 306 Unused T his code was used in a previous version. It is no long er used, but the code is reserved. 307 T emporary Redirect T he requested pag e has moved temporarily to a new url. 400 Bad Request T he server did not understand the request 401 Unauthorized T he requested pag e needs a username and a password 402 Payment Required You can not use this code yet 403 Forbidden Access is forbidden to the requested pag e 404 Not Found T he server can not find the requested pag e. 405 Method Not Allowed T he method specified in the request is not allowed. 406 Not Acceptable T he server can only g enerate a response that is not accepted by the client. 407 Proxy Authentication Required You must authenticate with a proxy server before this request can be served. 408 Request T imeout T he request took long er than the server was prepared to wait. 409 Conflict T he request could not be completed because of a conflict. 410 Gone T he requested pag e is no long er available. 411 Leng th Required T he "Content-Leng th" is not defined. T he server will not accept the request without it. 412 Precondition Failed T he precondition g iven in the request evaluated to false by the server. 413 Request Entity T oo Larg e T he server will not accept the request, because the request entity is too larg e. 414 Request-url T oo Long T he server will not accept the request, because the url is too long . Occurs when you convert a "post" request to a "g et" request with a long query information. 415 Unsupported Media T ype T he server will not accept the request, because the media type is not supported. 417 Expectation Failed 500 Internal Server Error T he request was not completed. T he server met an unexpected condition 501 Not Implemented T he request was not completed. T he server did not support the functionality required. 502 Bad Gateway T he request was not completed. T he server received an invalid response from the upstream server 503 Service Unavailable T he request was not completed. T he server is temporarily overloading or down.
- 3. 504 Gateway T imeout T he g ateway has timed out. 505 HT T P Version Not Supported T he server does not support the "http protocol" version. Methods to Set HTTP Status Code: T here are following methods which can be used to set HT T P Status Code in your servlet prog ram. T hese methods are available with HttpServletResponse object. S.N. Method & Desc ription 1 public void setStatus ( int statusCode ) T his method sets an arbitrary status code. T he setStatus method takes an int (the status code) as an arg ument. If your response includes a special status code and a document, be sure to call setStatus before actually returning any of the content with the PrintWriter. 2 public void sendRedirec t(String url) T his method g enerates a 302 response along with a Location header g iving the URL of the new document. 3 public void sendError(int c ode, String messag e) T his method sends a status code (usually 404) along with a short messag e that is automatically formatted inside an HTML document and sent to the client. HTTP Status Code Example: Following is the example which would send 407 error code to the client browser and browser would show you "Need authentication!!!" messag e. // Import required java libraries import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; // Extend HttpServlet class public class showError extends HttpServlet { // Method to handle GET method request. public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // Set error code and reason. response.sendError(407, "Need authentication!!!" ); } // Method to handle POST method request. public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } } Now calling the above servlet would display following result: HTTP STATUS 407 - NEED AUTHENTICATION!!! t ype Status report
- 4. message Need authentication!!! desc ript ion T he client must first authenticate itself with the proxy (Need authentication!!!). Apache Tomcat /5.5.29