com.sap.cloud.server.odata.http

Class HttpEntityHandler

java.lang.Object

com.sap.cloud.server.odata.EntityHandler

com.sap.cloud.server.odata.DefaultEntityHandler

com.sap.cloud.server.odata.http.HttpEntityHandler

public abstract class HttpEntityHandler
extends DefaultEntityHandler

An entity handler that delegates requests to a backend system using HTTP calls (e.g. REST/SOAP).

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	JSON Content type "application/json".
static java.lang.String	SOAP_1_1 Content type "text/xml" for SOAP 1.1.
static java.lang.String	SOAP_1_2 Content type "application/soap+xml" for SOAP 1.2.
static java.lang.String	TEXT Content type "text/plain".
static java.lang.String	XML Content type "application/xml".

Constructor Summary

Constructors

Constructor and Description
HttpEntityHandler(DataServlet servlet, DataService service) Construct an HTTP entity handler.
HttpEntityHandler(DataServlet servlet, DataService service, org.slf4j.Logger logger) Construct an HTTP entity handler.

Method Summary

Modifier and Type	Method and Description
DataValue	attributeValue(XmlElement element, java.lang.String name, DataType type, DataContext context) Parse data value from an XML attribute.
DataValue	attributeValue(XmlElement element, java.lang.String name, Property property, DataContext context) Parse data value from an XML attribute.
DataValue	attributeValueWithMatch(DataBindingPattern pattern, XmlElement element, java.lang.String name, DataType type, DataContext context) Parse data value from an XML attribute, matching a regular expression.
DataValue	attributeValueWithMatch(DataBindingPattern pattern, XmlElement element, java.lang.String name, Property property, DataContext context) Parse data value from an XML attribute, matching a regular expression.
ByteStream	byteStream(org.apache.http.HttpResponse response)
CharStream	charStream(org.apache.http.HttpResponse response)
void	checkFault(XmlElement envelope) Throw DataServiceException if the response contains a SOAP Fault.
void	checkStatus(org.apache.http.HttpResponse response) Throw DataServiceException if the response status is not 200-299.
void	close(boolean ok, CharStream stream, org.apache.http.client.methods.CloseableHttpResponse response) Close an HTTP response and stream, throwing an exception if the closing fails and 'ok' is true.
void	close(boolean ok, org.apache.http.client.methods.CloseableHttpResponse response) Close an HTTP response, throwing an exception if the closing fails and 'ok' is true.
DataContext	dataContext()
org.apache.http.client.methods.HttpUriRequest	delete(java.lang.String path, java.lang.Object... components)
DataValue	elementValue(XmlElement element, DataType type, DataContext context) Parse data value from the text of an XML element.
DataValue	elementValue(XmlElement element, Property property, DataContext context) Parse data value from the text of an XML element.
DataValue	elementValueWithMatch(DataBindingPattern pattern, XmlElement element, DataType type, DataContext context) Parse data value from the text of an XML element, matching a regular expression.
DataValue	elementValueWithMatch(DataBindingPattern pattern, XmlElement element, Property property, DataContext context) Parse data value from the text of an XML element, matching a regular expression.
java.lang.String	encodeURIComponent(java.lang.Object value) Percent-encode a URI component.
org.apache.http.client.methods.CloseableHttpResponse	execute(org.apache.http.client.methods.HttpUriRequest request) Execute an HTTP request.
org.apache.http.client.methods.CloseableHttpResponse	execute(org.apache.http.client.methods.HttpUriRequest request, java.lang.String accept) Execute an HTTP request.
DataValue	fieldValue(JsonObject object, java.lang.String field, DataType type, DataContext context) Parse data value from a field of a JSON object.
DataValue	fieldValue(JsonObject object, java.lang.String field, Property property, DataContext context) Parse data value from a field of a JSON object.
DataValue	fieldValueWithMatch(DataBindingPattern pattern, JsonObject object, java.lang.String field, DataType type, DataContext context) Parse data value from a field of a JSON object, matching a regular expression.
DataValue	fieldValueWithMatch(DataBindingPattern pattern, JsonObject object, java.lang.String field, Property property, DataContext context) Parse data value from a field of a JSON object, matching a regular expression.
org.apache.http.client.methods.HttpUriRequest	get(java.lang.String path, java.lang.Object... components)
JsonArray	getArray(JsonObject object, java.lang.String field) Get a field of a JSON object as a JSON array.
HttpDestination	getDestination()
java.lang.String	getDestinationURL(java.lang.String method, java.lang.String path, java.lang.Object... components) Return destination URL formed by appending a request path with optional path components.
JsonObject	getHeaders(org.apache.http.client.methods.CloseableHttpResponse response) Get the response headers from an HTTP request.
org.apache.http.client.HttpClient	getHttpClient()
org.slf4j.Logger	getLogger()
JsonObject	getObject(JsonObject object, java.lang.String field) Get a field of a JSON object as a JSON object.
org.apache.http.client.methods.HttpUriRequest	head(java.lang.String path, java.lang.Object... components)
boolean	isBackendHandler() Return does this entity handler delegate to a backend system (as opposed to the main service database).
boolean	isDebugEnabled()
boolean	isTraceEnabled()
JsonArray	jsonArray(CharStream stream) Parse a character stream to a JSON array.
JsonObject	jsonObject(CharStream stream) Parse a character stream to a JSON object.
void	logDebug(java.lang.String message) Log a debug message to this handler's logger.
void	logError(java.lang.String message, java.lang.RuntimeException cause) Log an error message to this handler's logger.
void	logTrace(java.lang.String message) Log a trace message to this handler's logger.
void	mustReturnKey(EntityValue entity) Check that an HTTP call returned values for all primary key properties.
org.apache.http.client.methods.HttpUriRequest	options(java.lang.String path, java.lang.Object... components)
org.apache.http.client.methods.HttpUriRequest	patch(java.lang.String path, java.lang.Object... components)
org.apache.http.client.methods.HttpUriRequest	post(java.lang.String path, java.lang.Object... components)
org.apache.http.client.methods.HttpUriRequest	put(java.lang.String path, java.lang.Object... components)
void	setContent(org.apache.http.client.methods.HttpUriRequest request, java.lang.Object content) Set the request body content for an HTTP request.
void	setContent(org.apache.http.client.methods.HttpUriRequest request, java.lang.Object content, java.lang.String contentType) Set the request body content for an HTTP request, and optionally set the Content-Type header.
void	setDestination(HttpDestination destination) Set the HTTP destination for this handler.
void	setHeaders(org.apache.http.client.methods.HttpUriRequest request, JsonObject headers) Set the request headers for an HTTP request.
org.apache.http.client.methods.HttpUriRequest	trace(java.lang.String path, java.lang.Object... components)
XmlElement	xmlElement(CharStream stream) Parse a character stream to an XML element.
java.lang.String	xmlText(java.lang.Object value) Convert an object to text for an XML element.

Methods inherited from class com.sap.cloud.server.odata.DefaultEntityHandler

createEntity, createLink, createMedia, deleteEntity, deleteLink, deleteStream, downloadMedia, downloadStream, executeQuery, getCacheDatabase, getClientRegistration, getDataService, getDataServlet, getNameForMetrics, headerValue, refreshAfter, refreshCache, updateEntity, updateLink, uploadMedia, uploadStream

Methods inherited from class com.sap.cloud.server.odata.EntityHandler

allowUnused, loadAll, loadPartition

Methods inherited from class java.lang.Object

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

Field Detail

JSON

public static final java.lang.String JSON

Content type "application/json".

See Also:

Constant Field Values

SOAP_1_1

public static final java.lang.String SOAP_1_1

Content type "text/xml" for SOAP 1.1.

See Also:

Constant Field Values

SOAP_1_2

public static final java.lang.String SOAP_1_2

Content type "application/soap+xml" for SOAP 1.2.

See Also:

Constant Field Values

TEXT

public static final java.lang.String TEXT

Content type "text/plain".

See Also:

Constant Field Values

XML

public static final java.lang.String XML

Content type "application/xml".

See Also:

Constant Field Values

Constructor Detail

HttpEntityHandler

public HttpEntityHandler(DataServlet servlet,
                         DataService service)

Construct an HTTP entity handler.

Parameters:

servlet - Data servlet, which communicates with the client.

service - Data service, which communicates with the database.

HttpEntityHandler

public HttpEntityHandler(DataServlet servlet,
                         DataService service,
                         org.slf4j.Logger logger)

Construct an HTTP entity handler.

Parameters:

servlet - Data servlet, which communicates with the client.

service - Data service, which communicates with the database.

logger - Logger to be used.

Method Detail

isBackendHandler

public boolean isBackendHandler()

Description copied from class: DefaultEntityHandler

Return does this entity handler delegate to a backend system (as opposed to the main service database).

Overrides:

isBackendHandler in class DefaultEntityHandler

Returns:

true.

getDestinationURL

public java.lang.String getDestinationURL(java.lang.String method,
                                          java.lang.String path,
                                          java.lang.Object... components)

Return destination URL formed by appending a request path with optional path components.

Parameters:

method - HTTP method (e.g. GET, POST); used only if logging is enabled.

path - Request path prefix. Assumed to already be percent-encoded if that is needed.

components - Trailing path components. Assumed to already be percent-encoded if that is needed.

Returns:

destination URL.

encodeURIComponent

public java.lang.String encodeURIComponent(java.lang.Object value)

Percent-encode a URI component.

Parameters:

value - Value to be converted to a string (via toString), then percent-encoded.

Returns:

Percent-encoded value.

getLogger

public org.slf4j.Logger getLogger()

Returns:

The logger that was provided to the constructor (may be null).

getDestination

public HttpDestination getDestination()

Returns:

HTTP destination for this handler. If not yet set, an HttpException will be thrown.

setDestination

public void setDestination(HttpDestination destination)

Set the HTTP destination for this handler.

Parameters:

destination - HTTP destination.

getHttpClient

public org.apache.http.client.HttpClient getHttpClient()

Returns:

HTTP client for this handler. If not yet set, an HttpException will be thrown.

delete

public org.apache.http.client.methods.HttpUriRequest delete(java.lang.String path,
                                                            java.lang.Object... components)

Parameters:

path - Request path.

components - Path components.

Returns:

HTTP DELETE request.

get

public org.apache.http.client.methods.HttpUriRequest get(java.lang.String path,
                                                         java.lang.Object... components)

Parameters:

path - Request path.

components - Path components.

Returns:

HTTP GET request.

head

public org.apache.http.client.methods.HttpUriRequest head(java.lang.String path,
                                                          java.lang.Object... components)

Parameters:

path - Request path.

components - Path components.

Returns:

HTTP HEAD request.

options

public org.apache.http.client.methods.HttpUriRequest options(java.lang.String path,
                                                             java.lang.Object... components)

Parameters:

path - Request path.

components - Path components.

Returns:

HTTP OPTIONS request.

patch

public org.apache.http.client.methods.HttpUriRequest patch(java.lang.String path,
                                                           java.lang.Object... components)

Parameters:

path - Request path.

components - Path components.

Returns:

HTTP PATCH request.

post

public org.apache.http.client.methods.HttpUriRequest post(java.lang.String path,
                                                          java.lang.Object... components)

Parameters:

path - Request path.

components - Path components.

Returns:

HTTP POST request.

put

public org.apache.http.client.methods.HttpUriRequest put(java.lang.String path,
                                                         java.lang.Object... components)

Parameters:

path - Request path.

components - Path components.

Returns:

HTTP PUT request.

trace

public org.apache.http.client.methods.HttpUriRequest trace(java.lang.String path,
                                                           java.lang.Object... components)

Parameters:

path - Request path.

components - Path components.

Returns:

HTTP TRACE request.

dataContext

public DataContext dataContext()

Returns:

Data context for the service of this handler.

setHeaders

public void setHeaders(org.apache.http.client.methods.HttpUriRequest request,
                       JsonObject headers)

Set the request headers for an HTTP request.

Parameters:

request - HTTP request.

headers - Request headers, represented as a JSON object.

getHeaders

public JsonObject getHeaders(org.apache.http.client.methods.CloseableHttpResponse response)

Get the response headers from an HTTP request.

Parameters:

response - HTTP response.

Returns:

Response headers, represented as a JSON object with all header names in lowercase.

setContent

public void setContent(org.apache.http.client.methods.HttpUriRequest request,
                       java.lang.Object content)

Set the request body content for an HTTP request.

Parameters:

request - HTTP request.

content - Request body.

setContent

public void setContent(org.apache.http.client.methods.HttpUriRequest request,
                       java.lang.Object content,
                       java.lang.String contentType)

Set the request body content for an HTTP request, and optionally set the Content-Type header.

Parameters:

request - HTTP request.

content - Request body.

contentType - Content type (or null if it is to be automatically determined from the content).

execute

public org.apache.http.client.methods.CloseableHttpResponse execute(org.apache.http.client.methods.HttpUriRequest request)

Execute an HTTP request.

Parameters:

request - HTTP request.

Returns:

HTTP response.

execute

public org.apache.http.client.methods.CloseableHttpResponse execute(org.apache.http.client.methods.HttpUriRequest request,
                                                                    java.lang.String accept)

Execute an HTTP request.

Parameters:

request - HTTP request.

accept - For HTTP Accept header (or null if an Accept header is not required or is already set).

Returns:

HTTP response.

byteStream

public ByteStream byteStream(org.apache.http.HttpResponse response)

Parameters:

response - HTTP response.

Returns:

HTTP response body as a byte stream.

charStream

public CharStream charStream(org.apache.http.HttpResponse response)

Parameters:

response - HTTP response.

Returns:

HTTP response body as a character stream.

checkFault

public void checkFault(XmlElement envelope)

Throw DataServiceException if the response contains a SOAP Fault.

Parameters:

response - SOAP Envelope.

checkStatus

public void checkStatus(org.apache.http.HttpResponse response)

Throw DataServiceException if the response status is not 200-299.

Parameters:

response - HTTP response.

jsonArray

public JsonArray jsonArray(CharStream stream)

Parse a character stream to a JSON array.

Parameters:

stream - Character stream.

Returns:

JSON array.

jsonObject

public JsonObject jsonObject(CharStream stream)

Parse a character stream to a JSON object.

Parameters:

stream - Character stream.

Returns:

JSON object.

xmlElement

public XmlElement xmlElement(CharStream stream)

Parse a character stream to an XML element.

Parameters:

stream - Character stream.

Returns:

XML element.

xmlText

public java.lang.String xmlText(java.lang.Object value)

Convert an object to text for an XML element.

Parameters:

value - Object (can be null).

Returns:

Empty string (if value is null), otherwise value.toString().

attributeValue

public DataValue attributeValue(XmlElement element,
                                java.lang.String name,
                                Property property,
                                DataContext context)

Parse data value from an XML attribute.

Parameters:

element - XML element containing the attribute.

name - XML attribute name.

property - Property metadata (e.g. data type) for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

attributeValue

public DataValue attributeValue(XmlElement element,
                                java.lang.String name,
                                DataType type,
                                DataContext context)

Parse data value from an XML attribute.

Parameters:

element - XML element containing the attribute.

name - XML attribute name.

type - Data type for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

attributeValueWithMatch

public DataValue attributeValueWithMatch(DataBindingPattern pattern,
                                         XmlElement element,
                                         java.lang.String name,
                                         Property property,
                                         DataContext context)

Parse data value from an XML attribute, matching a regular expression.

Parameters:

pattern - Regular expression pattern.

element - XML element containing the attribute.

name - XML attribute name.

property - Property metadata (e.g. data type) for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

attributeValueWithMatch

public DataValue attributeValueWithMatch(DataBindingPattern pattern,
                                         XmlElement element,
                                         java.lang.String name,
                                         DataType type,
                                         DataContext context)

Parse data value from an XML attribute, matching a regular expression.

Parameters:

pattern - Regular expression pattern.

element - XML element containing the attribute.

name - XML attribute name.

type - Data type for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

elementValue

public DataValue elementValue(XmlElement element,
                              Property property,
                              DataContext context)

Parse data value from the text of an XML element.

Parameters:

element - XML element to be parsed.

property - Property metadata (e.g. data type) for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

elementValue

public DataValue elementValue(XmlElement element,
                              DataType type,
                              DataContext context)

Parse data value from the text of an XML element.

Parameters:

element - XML element to be parsed.

type - Data type for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

elementValueWithMatch

public DataValue elementValueWithMatch(DataBindingPattern pattern,
                                       XmlElement element,
                                       Property property,
                                       DataContext context)

Parse data value from the text of an XML element, matching a regular expression.

Parameters:

pattern - Regular expression pattern.

element - XML element to be parsed.

property - Property metadata (e.g. data type) for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

elementValueWithMatch

public DataValue elementValueWithMatch(DataBindingPattern pattern,
                                       XmlElement element,
                                       DataType type,
                                       DataContext context)

Parse data value from the text of an XML element, matching a regular expression.

Parameters:

pattern - Regular expression pattern.

element - XML element to be parsed.

type - Data type for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

fieldValue

public DataValue fieldValue(JsonObject object,
                            java.lang.String field,
                            Property property,
                            DataContext context)

Parse data value from a field of a JSON object.

Parameters:

object - JSON object to be parsed.

field - Field name within JSON object.

property - Property metadata (e.g. data type) for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

fieldValue

public DataValue fieldValue(JsonObject object,
                            java.lang.String field,
                            DataType type,
                            DataContext context)

Parse data value from a field of a JSON object.

Parameters:

object - JSON object to be parsed.

field - Field name within JSON object.

type - Data type for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

fieldValueWithMatch

public DataValue fieldValueWithMatch(DataBindingPattern pattern,
                                     JsonObject object,
                                     java.lang.String field,
                                     Property property,
                                     DataContext context)

Parse data value from a field of a JSON object, matching a regular expression.

Parameters:

pattern - Regular expression pattern.

object - JSON object to be parsed.

field - Field name within JSON object.

property - Property metadata (e.g. data type) for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

fieldValueWithMatch

public DataValue fieldValueWithMatch(DataBindingPattern pattern,
                                     JsonObject object,
                                     java.lang.String field,
                                     DataType type,
                                     DataContext context)

Parse data value from a field of a JSON object, matching a regular expression.

Parameters:

pattern - Regular expression pattern.

object - JSON object to be parsed.

field - Field name within JSON object.

type - Data type for the value to be parsed.

context - Data context for parsing.

Returns:

Parsed data value.

getArray

public JsonArray getArray(JsonObject object,
                          java.lang.String field)

Get a field of a JSON object as a JSON array. If the field is missing or null, return an empty array. If the field value is not an array, create an array and add the value to it, then return the new array.

Parameters:

object - JSON object

field - Field name.

Returns:

JSON array.

getObject

public JsonObject getObject(JsonObject object,
                            java.lang.String field)

Get a field of a JSON object as a JSON object. If the field is missing or null, return an empty object. If the field value is not a JSON object, throw JsonException.

Parameters:

object - JSON object

field - Field name.

Returns:

JSON object.

close

public void close(boolean ok,
                  org.apache.http.client.methods.CloseableHttpResponse response)

Close an HTTP response, throwing an exception if the closing fails and 'ok' is true.

Parameters:

ok - Was everything already OK with the response (i.e. caller is not currently handling an exception).

response - HTTP response.

close

public void close(boolean ok,
                  CharStream stream,
                  org.apache.http.client.methods.CloseableHttpResponse response)

Close an HTTP response and stream, throwing an exception if the closing fails and 'ok' is true.

Parameters:

ok - Was everything already OK with the response (i.e. caller is not currently handling an exception).

stream - Response stream.

response - HTTP response.

mustReturnKey

public void mustReturnKey(EntityValue entity)

Check that an HTTP call returned values for all primary key properties.

Parameters:

entity - Entity which is expected to already hold values for all key properties.

logError

public void logError(java.lang.String message,
                     java.lang.RuntimeException cause)

Log an error message to this handler's logger.

Parameters:

message - Log message.

cause - Associated exception (or null).

logDebug

public void logDebug(java.lang.String message)

Log a debug message to this handler's logger.

Parameters:

message - Log message.

logTrace

public void logTrace(java.lang.String message)

Log a trace message to this handler's logger.

Parameters:

message - Log message.

isDebugEnabled

public boolean isDebugEnabled()

Returns:

true if debug-level logging is enabled for this handler's logger.

isTraceEnabled

public boolean isTraceEnabled()

Returns:

true if trace-level logging is enabled for this handler's logger.