Package jmri.web.servlet.json

Class JsonServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

org.eclipse.jetty.websocket.servlet.WebSocketServlet

jmri.web.servlet.json.JsonServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

@WebServlet(name="JsonServlet",
            urlPatterns="/json")
public class JsonServlet
extends org.eclipse.jetty.websocket.servlet.WebSocketServlet

Provide JSON formatted responses to requests for information from the JMRI Web Server.

See jmri.server.json for details on how this Servlet handles JSON requests.

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
JsonServlet()

Method Summary

Modifier and Type	Method	Description
void	configure(org.eclipse.jetty.websocket.servlet.WebSocketServletFactory factory)
protected void	doDelete(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
protected void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)	Handle HTTP get requests for JSON data.
protected void	doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
protected void	doPut(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
void	init()
(package private) void	superInit()	Package private method to call WebSocketServlet.init() so this call can be mocked out in unit tests.

Methods inherited from class org.eclipse.jetty.websocket.servlet.WebSocketServlet

destroy, service

Methods inherited from class javax.servlet.http.HttpServlet

doHead, doOptions, doTrace, getLastModified, service

Methods inherited from class javax.servlet.GenericServlet

getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

JsonServlet

public JsonServlet()

Method Details

init

public void init()
          throws javax.servlet.ServletException

Overrides:

init in class org.eclipse.jetty.websocket.servlet.WebSocketServlet

Throws:

javax.servlet.ServletException

superInit

void superInit()
        throws javax.servlet.ServletException

Package private method to call WebSocketServlet.init() so this call can be mocked out in unit tests.

Throws:

javax.servlet.ServletException - if unable to initialize server

configure

public void configure(org.eclipse.jetty.websocket.servlet.WebSocketServletFactory factory)

Specified by:

configure in class org.eclipse.jetty.websocket.servlet.WebSocketServlet

doGet

protected void doGet(javax.servlet.http.HttpServletRequest request,
 javax.servlet.http.HttpServletResponse response)
              throws IOException

Handle HTTP get requests for JSON data. Examples:

• /json/v5/sensor/IS22 (return data for sensor with system name "IS22")
• /json/v5/sensor (returns a list of all sensors known to JMRI)

sample responses:

• {"type":"sensor","data":{"name":"IS22","userName":"FarEast","comment":null,"inverted":false,"state":4}}
• [{"type":"sensor","data":{"name":"IS22","userName":"FarEast","comment":null,"inverted":false,"state":4}}]

Note that data will vary for each type. Note that if an array is returned when requesting a single object, the client must resolve the multiple objects in the array, since it is possible for plugins to JMRI to provide their own response, and JMRI is incapable of judging the correctness of the plugin's response.

If the request includes a result attribute, the content of the response will be solely the contents of that attribute. This is an aid to the development and testing of JMRI and clients, but is not considered a usable feature in production. This capability may be removed without notice if it is deemed too complex to maintain.

Overrides:

doGet in class javax.servlet.http.HttpServlet

Parameters:

request - an HttpServletRequest object that contains the request the client has made of the servlet

response - an HttpServletResponse object that contains the response the servlet sends to the client

Throws:

IOException - if an input or output error is detected when the servlet handles the GET request

doPost

protected void doPost(javax.servlet.http.HttpServletRequest request,
 javax.servlet.http.HttpServletResponse response)
               throws IOException

Overrides:

doPost in class javax.servlet.http.HttpServlet

Throws:

IOException

doPut

protected void doPut(javax.servlet.http.HttpServletRequest request,
 javax.servlet.http.HttpServletResponse response)
              throws IOException

Overrides:

doPut in class javax.servlet.http.HttpServlet

Throws:

IOException

doDelete

protected void doDelete(javax.servlet.http.HttpServletRequest request,
 javax.servlet.http.HttpServletResponse response)
                 throws javax.servlet.ServletException,
IOException

Overrides:

doDelete in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException