I am relative new in WSO2 to create services, and i have to do a project in the enterprise where i work. First i had to take a message in, for example, json and send xml. I was able to do so, with this code:
<?xml version="1.0" encoding="UTF-8"?>
<api context="/Test" name="JsonToXmlApi" xmlns="http://ws.apache.org/ns/synapse">
<resource methods="POST" uri-template="/xml/">
<inSequence>
<property name="messageType" scope="axis2" type="STRING" value="text/xml"/>
<header action="remove" name="To" scope="default"/>
<property name="RESPONSE" scope="default" type="STRING" value="true"/>
<send/>
</inSequence>
<outSequence/>
<faultSequence/>
</resource>
</api>
Now i need to do the following, i have to send a message in SOAP, XML format, consume it in SOAP and receive back with JSON or XML format.
Someone could help me? I am asking because i am searching for tutorials, for beginners, about it for more than a week, and wasn't able to solve my problem.
Another question, would be possible to do this in REST API project?
If someone could help me, with a detailed tutorial or good video teaching that, i would be grateful.
Thank you.
Your post is a bit unclear but I will try to summarise the typical common combinations of input interface, wso2 component and backend services when you are developing web services.
Web services are services you can invoke over http or https - you might have three types of interfaces for these and you might use two types of WSO2 ESB components - proxy and API - to develop these.
1) Input/Output: JSON
WSO2 component: API
Backend: Any (JSon/XML/SOAP)
2) Input/Output: Plain XML
WSO2 component: API
Backend: Any (JSon/XML/SOAP)
3) Input/Output: SOAP
WSO2 component: Proxy
Backend: Any (JSon/XML/SOAP)
One of the key components of any SOAP service is the WSDL - the WSO2 proxy allows you to publish a WSDL so that your caller knows what sort of data and operations your service provides.
See more here: https://docs.wso2.com/display/EI611/Working+with+Proxy+Services
Adding this note only because you asked:
Technically, you might be able to receive a SOAP message in an API component because SOAP is just an XML document - but it would be really pointless. The purpose of the API component is to expose resources and allow you to perform HTTP operations (GET, POST etc) on those resources (this model can be called REST).
The purpose of a SOAP based web service is to expose data and operations as defined in a WSDL and the WSO2 proxy component is what allows you to do that.
Related
With Nlog 4.4.5 am trying to use protocol JsonPost of WebService target to post logs to slack. Slack webhooks need Json data over https post (https://api.slack.com/incoming-webhooks)
<target xsi:type="WebService"
name="slack"
url="https://hooks.slack.com/services/T*****/B4T****/7F********XDv9h/"
protocol="JsonPost"
encoding="utf-8"
>
<parameter name="text" type="System.String" layout="${date:format=yyyy-MM-dd HH\:mm\:ss.fff}: ${level} - ${message}"/>
</target>
It does not post anything to my slack channel created for the webhook whereas I see the other targets in my Nlog.config are called and log files are populated with new data.
Any idea where I should look into to sort it out?
The problem was with the ending "/" in the Slack webhook url. Removed and it started posting logs to my slack channel.
Maybe something like this answer:
https://github.com/NLog/NLog/issues/1958
While waiting for this issue to be resolved (Using JSON-Layout directly):
https://github.com/NLog/NLog/issues/1905
I have setup a REST endpoint in WSO2 AM that calls out to another REST endpoint. When the call is made I am receiving a 411 response code. The request contains a JSON body, the content type and accepts header are set to application/json. I can curl the backing service that WSO2 is accessing directly with the same params and it works correctly. It seems that WSO2 AM is stripping or not sending the content-length.
Why is the content length not being sent to the REST endpoint that is being accessed?
Sending content-length is disabled by default because it can cause performance degradation. But you can enable it by adding following to the api's insequence. (see https://docs.wso2.com/display/AM1100/Adding+Mediation+Extensions on adding custom sequence to an api)
<property name="COPY_CONTENT_LENGTH_FROM_INCOMING" value="true" scope="axis2"/>
<property name="FORCE_HTTP_CONTENT_LENGTH" scope="axis2" value="true"></property>
following is a sample sequnce
<sequence xmlns="http://ws.apache.org/ns/synapse" name="contentLengthadd">
<property name="COPY_CONTENT_LENGTH_FROM_INCOMING" value="true" scope="axis2"/>
<property name="FORCE_HTTP_CONTENT_LENGTH" scope="axis2" value="true"></property>
</sequence>
This sequence will get the content length from incoming request request and pass it the request header to the backend.
you can read more about these two properties in https://docs.wso2.com/display/ESB481/HTTP+Transport+Properties#HTTPTransportProperties-FORCE_HTTP_CONTENT_LENGTH
There are numerous examples of using the mailto transport in WSO2 ESB to send emails (based on filter mediator, fault sequence etc.). However, I have attempted this a number of ways all with the same result i.e. that the proxy service never terminates. I am testing this using SOAPUi.
This is my proxy service
<proxy xmlns="http://ws.apache.org/ns/synapse" name="TMCService" transports="https,http" statistics="enable" trace="enable" startOnLoad="true">
<target inSequence="gov:/trunk/sequences/seqGetTMCData">
<outSequence>
<filter xmlns:trac="http://mynamespaceuri" xpath="//trac:SaveIncidentsResponse">
<then>
<log level="full"/>
<property name="Subject" value="CEP Event" scope="transport"/>
<property name="OUT_ONLY" value="true"/>
<send>
<endpoint>
<address uri="mailto:conrad.crampton#gmail.com"/>
</endpoint>
</send>
</then>
<else>
<send/>
</else>
</filter>
</outSequence>
</target>
<description></description>
</proxy>
the email sends no problem with the response from the inSequence - no problem, it just never terminates. I have to manually stop it in SOAPUi to stop.
I've tried putting drop after the send in the then element, that doesn't work either.
I guess I am missing something fundamental in how I am understanding the out sequence to work, but this is pretty much lifted from the many examples out there and no one else appears to be having the same issue as me.
Any suggestions/ pointers??
WSO2 ESB v4.5.1
I have resolved this by cloning the response message, sending one to the mailto transport and sending the other one as a default send (no endpoint) which returns back to the client.
Kind of makes sense as the OUT_ONLY property is explicitly saying there will be no response, so have ensure that the client receives one by cloning the message.
Still welcome any other comments if there is another way of doing this without clone mediator.
So why doesn't the examples show this!
Hello WSO2 community and hello Stackoverflow,
my testing of the SOA suite starting from the ESB is going good: now the ESB recognises external services, create correct proxies that return correct results.
SOLVED
About that, I have two issues: the first is that the "try it"
functionality raises the exception:
"Cannot find dispatch method for {http://schemas.xmlsoap.org/soap/envelope/}Envelope
[tagOpened]/soapenv:Text[tagClosed]"
when i try to send a SOAP enveloped created for the mock service of
the web service proxied.
Anyway, if I try the proxy service from an external client (created on
Netbeans) it works great.
ANSWER
For the first part, the reason is most probably the cross domain issue as try-it is sending messages through a java script stub from
the browser. You will notice that this works great when the service
itself is hosted in the ESB itself, because the request passes through
the same domain. This is why, although, it works perfectly through a
normal client invocation, it does not work through try-it.
The second issue is that I'm not able to orchestrate two services. My objective is sending the input of the first service to the second service, and then to the user.
I'm working on the tutorial Tharindu Mathew suggested: everything now makes sense to me except on one thing: the XSLT transformation.
Here is the out sequence the tutorial suggests you to create:
<outSequence xmlns="http://ws.apache.org/ns/synapse">
<switch source="get-property('STATE')">
<case regex="PERSON_INFO_REQUEST">
<log level="full">
<property name="sequence" value="outSequence - STATE 01 - response from PersonInfoService" />
</log>
<xslt key="xslt">
<property name="amount" expression="get-property('ORG_AMOUNT')" />
</xslt>
<log level="full">
<property name="sequence" value="outSequence - STATE 01 - request for CreditService" />
</log>
<property name="STATE" value="CREDIT_REQUEST" />
<send>
<endpoint key="CreditEpr" />
</send>
</case>
<case regex="CREDIT_REQUEST">
<log level="full">
<property name="sequence" value="outSequence - STATE 02 - response from CreditService" />
</log>
<send />
</case>
</switch>
</outSequence>
Now, focusing on the XSLT node of the first case of the switch, you can see that there's just a get for the amount property.
So that I think we have an XML from the in sequence that states the ID, and this get on the amount property (and I don't know what it does).
The tutorial then suggests:
To create the request to this CrediService, we use the following XSLT with the XSLT mediator. Note, we are using the ORG_ID that we stored in this XSLT as a XSLT parameter and using the XSLT mediator as well.
And here is the XSLT showed in the tutorial:
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:fn="http://www.w3.org/2005/02/xpath-functions"
xmlns:ns="http://samples.esb.wso2.org"
xmlns:ax21="http://samples.esb.wso2.org/xsd"
exclude-result-prefixes="ns fn">
<xsl:param name="amount"/>
<xsl:output method="xml" omit-xml-declaration="yes" indent="yes"/>
<xsl:template match="/">
<xsl:apply-templates select="//ns:getResponse" />
</xsl:template>
<xsl:template match="ns:getResponse" xmlns:ns="http://samples.esb.wso2.org">
<sam:credit xmlns:sam="http://samples.esb.wso2.org" xmlns:xsd="http://samples.esb.wso2.org/xsd">
<sam:info>
<xsd:amount><xsl:value-of select="$amount"/></xsd:amount>
<xsd:personInfo>
<xsd:address><xsl:value-of select="ns:return/ax21:address"/></xsd:address>
<xsd:id><xsl:value-of select="ns:return/ax21:id"/></xsd:id>
<xsd:name><xsl:value-of select="ns:return/ax21:name"/></xsd:name>
</xsd:personInfo>
</sam:info>
</sam:credit>
</xsl:template>
</xsl:stylesheet>
I was asked to put a similar file into the resources directory of WSO2 ESB, but this file is never used in the tutorial:
Copy the personToCredit.xslt in the sample zip to resources directory of WSO2 ESB.
---------LITTLE PARENTHESIS-----------
The WSDL file was not used either after it was stated:
Copy the CreditProxy.wsdl in the sample zip to the resources directory of the WSO2 ESB.
I cannot find the WSDL file in the Configuration/Governance Registry, and I don't know how to address it, so I chose to specify it inline instead.
---------LITTLE PARENTHESIS END-----------
This sentence is followed by the XSLT file text. My main question now is:
Where should I put this XSLT? I do not know where to put the XSLT mediator, neither how to build it.
Should I rely on registries?
A perfect answer could be the code of the out sequence, and the specified connection with the XSLT mediator suggested.
OverTheBitStair
Hi OverTheBitStair (nice nick!),
For the first part, the reason is most probably the cross domain issue as try-it is sending messages through a java script stub from the browser. You will notice that this works great when the service itself is hosted in the ESB itself, because the request passes through the same domain. This is why, although, it works perfectly through a normal client invocation, it does not work through try-it.
For the second part, the short answer is yes, it is possible. In terms of the ESB, we refer to it as a light-weight orchestration engine in addition to being a mediation engine. This means for light-weight and short-lived (<1 day) processes we can solve the orchestration requirements using the ESB without bringing in the Business Process Server.
To do this, we use this method called service chaining. What it does is introduce a method to get some output out of the initial service invocation and use it in a subsequent invocation. The article WSO2 ESB by example - Service Chaining should help you with implementation details on what you are looking for.
Hope this helps.
If you create a service chaining scenario where your proxy service calls two other services and return the result to the caller of the proxy service, it would look something like this:
Caller --> Proxy Service -- seq_A --> Service1 -- seq_B --> Service2 -- seq_C --> (proxy serviced response) --> Caller
In this case, seq_A would be the in sequence of the proxy service, seq_C the out sequence of the proxy service and seq_B another named sequence.
Input, i.e. the message body, to seq_A would be the input to proxy service. seq_A would contain a send mediator at the end and at that point in the sequence the message context would be the input to Service1. The send mediator also points to seq_B to be executed for the reply.
At start of seq_B the message body contains the output from Service1. If you want to keep some message data from before the service call you need to save that in properties in the context.
At the end of seq_B you would have a send mediator; at that point the message body should contain the input to Service2, The send mediator would in this case not need to point to an explicit reply sequence, if seq_C is the out sequence of the proxy service - that one will be used by default then.
When seq_C is executing the message body at that point is the response from Service2. Again, if you need to use/combine with some data prior to the call to Service2, you need that to be saved into properties.
Depending on the particular needs for the input and transformations needed at each step it can be fairly straightforward or a bit cumbersome to handle.
What also should taken into consideration is what needs to happen in error scenarios, as this may add some additional complexity, depending on the requirements.
I am writing a Spring Restful webservices application using Spring MVC. I have used content negotiating viewer to respond multiple data formats for eg. If some one requests a URL with .xml extension an XML will be sent in response body similarly if someone requests with an .json extension, an json will be sent in response body.
Now, I want the same process inwards, say if some body wants to post a Json or xml or a simple post from a webpage form using post method to same action, it should be able to handle all these.
This way i will be able to write a Web Service+Web Application in a single Spring MVC+Restful Application.
Thanks in advance for the help :)
You can use headers attribute of #RequestMapping annotation.
#RequestMapping(value = "/pets", method = RequestMethod.POST, headers="content-type=text/*")
to narrow content-type of requests your method is going to serve.
edit:
If you want to sent different content type in request body, then the only thing you need to do is to define MessageConverter (I assume you already did that) and annotate your method parameter with
#RequestBody
Spring should deserialize the body of your request using the MessageConverter you defined.
So assuming you have something like:
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="messageConverters">
<util:list>
<bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"/>
</util:list>
</property>
</bean>
<bean id="contentNegotiatingViewResolver" class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
<property name="mediaTypes">
<util:map>
<entry key="json" value="application/json"/>
</util:map>
</property>
<property name="defaultViews">
<util:list>
<bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView"/>
</util:list>
</property>
</bean>
in your spring context.
Annotating your method like this:
#RequestMapping(method=PUT, value="/user/{user_id}")
public void putUser(#RequestBody User user, #PathVariable int user_id) {
...
}
should do the job.
You don't have to do anything. You register converts and they will in turn tell "spring" what Content-types they can handle. XStream registers application/xml and text/xml (perhaps more), jackson registers application/json and so on.
It's all available at http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/mvc.html#mvc-ann-responsebody
I also don't like the filename-standard, I prefer to leave that to the same converter. In that case it will look at the Accept-header. If you want json, set Accepts: application/json.