org.eclipse.smila.http.server.json
Class JsonHttpHandler

java.lang.Object
  org.eclipse.smila.http.server.json.JsonHttpHandler

All Implemented Interfaces:

HttpHandler

public abstract class JsonHttpHandler
extends java.lang.Object
implements HttpHandler

Common base class for HTTP handlers that expect a single JSON CEO as input and produce a single CEO in case of successful processing.

Author:

jschumacher

Field Summary

protected static JsonHttpUtils

HTTP_UTILS Utilities for JSON-Request/Response handling.

Constructor Summary

JsonHttpHandler()

Method Summary

protected int	getErrorStatus(java.lang.String method, java.lang.String requestUri, java.lang.Throwable ex) Return a status code for an exception.
protected int	getSuccessStatus(java.lang.String method, java.lang.String requestUri)
protected int	getSuccessStatus(java.lang.String requestMethod, java.lang.String requestUri, Record inputRecord, java.lang.Object resultObject) Returns the success code.
void	handle(HttpExchange exchange) reads a record from the JSON request, calls process(Record) to do processing and get a result record and writes JSON result.
protected boolean	isValidMethod(java.lang.String method, java.lang.String requestUri)
abstract java.lang.Object	process(Record inputRecord) process input record and return result record.
protected boolean	writeErrorResult(HttpExchange exchange, java.lang.Throwable error, Record inputRecord) write an error result.
protected void	writeResultObject(java.io.OutputStream responseStream, java.lang.Object resultObject) write result object.
protected boolean	writeSuccessResult(HttpExchange exchange, java.lang.Object resultObject, Record inputRecord) write a successful result.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.smila.http.server.HttpHandler

getRootContextPath

Field Detail

HTTP_UTILS

protected static final JsonHttpUtils HTTP_UTILS

Utilities for JSON-Request/Response handling.

Constructor Detail

JsonHttpHandler

public JsonHttpHandler()

Method Detail

process

public abstract java.lang.Object process(Record inputRecord)
                                  throws java.lang.Exception

process input record and return result record.

Parameters:

inputRecord - input Record

Returns:

result record. May be null.

Throws:

java.lang.Exception - any failure during processing.

handle

public void handle(HttpExchange exchange)

reads a record from the JSON request, calls process(Record) to do processing and get a result record and writes JSON result. Handles a HttpExchange containing a HttpRequest.

Specified by:

handle in interface HttpHandler

Parameters:

exchange - the HttpExchange object

isValidMethod

protected boolean isValidMethod(java.lang.String method,
                                java.lang.String requestUri)

Parameters:

method - HTTP method

requestUri - request URI

Returns:

true if the method is valid for this handler. Default is "POST".

writeSuccessResult

protected boolean writeSuccessResult(HttpExchange exchange,
                                     java.lang.Object resultObject,
                                     Record inputRecord)
                              throws java.io.IOException

write a successful result.

Parameters:

exchange - HTTP exchange

resultObject - result object

inputRecord - input record parsed either from request body, if it has content, or from request URI parameters.

Returns:

if the connection should be closed after everything is finished.

Throws:

java.io.IOException - error writing the result.

getSuccessStatus

protected int getSuccessStatus(java.lang.String method,
                               java.lang.String requestUri)

Returns:

the status code to return for successful requests. By default it is "OK" (200).

getSuccessStatus

protected int getSuccessStatus(java.lang.String requestMethod,
                               java.lang.String requestUri,
                               Record inputRecord,
                               java.lang.Object resultObject)

Returns the success code.

Parameters:

requestMethod - HTTP method

requestUri - request URI

inputRecord - input record

resultObject - result object returned from process

Returns:

the status code to return for successful requests using the method and request URI.

writeResultObject

protected void writeResultObject(java.io.OutputStream responseStream,
                                 java.lang.Object resultObject)
                          throws java.io.IOException

write result object. The default implementation writes back single Record results. Subclasses that produce different result types must override this method.

Parameters:

responseStream - response stream

resultObject - result object.

Throws:

java.io.IOException - error writing result

writeErrorResult

protected boolean writeErrorResult(HttpExchange exchange,
                                   java.lang.Throwable error,
                                   Record inputRecord)
                            throws java.io.IOException

write an error result.

Parameters:

exchange - HTTP exchange

error - the exception causing the error.

inputRecord - the input record.

Returns:

if the connection should be closed after everything is finished.

Throws:

java.io.IOException - error writing the result.

getErrorStatus

protected int getErrorStatus(java.lang.String method,
                             java.lang.String requestUri,
                             java.lang.Throwable ex)

Return a status code for an exception.

See Also:

HTTP_UTILS#getErrorStatus(String, String, Throwable)