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Difference between revisions of "Stardust/Knowledge Base/Web Service API/Structured Data Types as JAXB Objects"
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== Introduction == | == Introduction == | ||
| − | Currently, | + | Currently, Stardust WS API expects out data in the form of ParametersXto which in turn takes list of ParameterXto. This ParameterXto is easy to use for primitive data types, but for structure data type (SDT) we (WS Client) further need to create new XmlValueXto with some implementation of org.w3c.dom.Element with children and/or attributes to form required xml structure. |
| − | Here one creates the implementation of the Element, and populate the required xml structure | + | Here one creates the implementation of the Element, and populate the required xml structure (as per your process SDT) and pass it to XmlValueXto and finally, pass the ParametersXto to the completeActivity method as out data. All this is not easy for WS consumer to deal with and can be avoided with the approach mentioned in this article. |
| − | This article provides the work around and utility code for | + | This article provides the work around and utility code for Stardust WS consumers to enable them to use SDTs as JAXB objects. |
| − | For this article, it is assumed that you already worked with Stardust WS API. | + | For this article, it is assumed that you have already worked with Stardust WS API. |
== Example Process == | == Example Process == | ||
| − | To demonstrate, we will use the following process | + | To demonstrate, we will use the following process. There are only two activities. The first activity updates structure data types, StudentData and Institute. The second activity just shows the updated data. |
| − | + | '''The Process''' | |
| − | + | [[Image:Stardust SDTProcess.jpg]] | |
| − | + | StudData and Institute Sructure Data | |
| + | |||
| + | The process data of type structured data ''StudentData'' and ''InstituteData ''are defined by the following XSDs | ||
StudentData XSD: <source lang="XML"> | StudentData XSD: <source lang="XML"> | ||
<?xml version="1.0" encoding="UTF-8"?> | <?xml version="1.0" encoding="UTF-8"?> | ||
| − | <xsd:schema xmlns:stu="http://www.infinity.com/bpm/model/WSModelWithSDT/StudentData" xmlns:xsd="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.infinity.com/bpm/model/WSModelWithSDT/StudentData"> | + | <xsd:schema xmlns:stu="http://www.infinity.com/bpm/model/WSModelWithSDT/StudentData" |
| + | xmlns:xsd="http://www.w3.org/2001/XMLSchema" | ||
| + | targetNamespace="http://www.infinity.com/bpm/model/WSModelWithSDT/StudentData"> | ||
<xsd:complexType name="StudentData"> | <xsd:complexType name="StudentData"> | ||
<xsd:sequence> | <xsd:sequence> | ||
| Line 35: | Line 39: | ||
<br>Institue XSD: <source lang="XML"> | <br>Institue XSD: <source lang="XML"> | ||
<?xml version="1.0" encoding="UTF-8"?> | <?xml version="1.0" encoding="UTF-8"?> | ||
| − | <xsd:schema xmlns:ins="http://www.infinity.com/bpm/model/WSModelWithSDT/Institute" xmlns:xsd="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.infinity.com/bpm/model/WSModelWithSDT/Institute"> | + | <xsd:schema xmlns:ins="http://www.infinity.com/bpm/model/WSModelWithSDT/Institute" |
| + | xmlns:xsd="http://www.w3.org/2001/XMLSchema" | ||
| + | targetNamespace="http://www.infinity.com/bpm/model/WSModelWithSDT/Institute"> | ||
<xsd:complexType name="Institute"> | <xsd:complexType name="Institute"> | ||
<xsd:sequence> | <xsd:sequence> | ||
| Line 46: | Line 52: | ||
</source> | </source> | ||
| − | == | + | == Structured Data Usage on the Stardust WS-API == |
| − | Usually you can form the required XML element according to the SDT schema mannually and pass it | + | Usually you can form the required XML element according to the SDT schema mannually and pass it to the API in the form of String object. This is explained by the code snippets below. |
| − | + | Here, 'TakeInSTDAndShow' is the ID of the above shown process. The 'StudData' is the ID of StudentData structured type. | |
<source lang="Java"> | <source lang="Java"> | ||
| Line 78: | Line 84: | ||
workflowService.completeActivity(activateNextActivityForProcess | workflowService.completeActivity(activateNextActivityForProcess | ||
| − | .getOid(), null, outData, true); | + | .getOid(), null, outData, true); |
| − | + | ||
| − | + | ||
} | } | ||
</source> | </source> | ||
| − | == | + | == Structured Data Types as JAXB Objects == |
| − | As explained in the previous section, forming XML data elements | + | As explained in the previous section, forming XML data elements manually is very tedious and error prone task expecially for complex SDT. |
| − | In this section we will see that how we can use the JAXB here to make life easier. Take a look at code snippets below; | + | In this section we will see that how we can use the JAXB here to make life easier. Take a look at code snippets below; |
<source lang="Java"> | <source lang="Java"> | ||
| Line 131: | Line 135: | ||
</source> | </source> | ||
| − | + | | |
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | If you noticed, here we have replaced the manual task of forming XML elements with JAXB objects. The changes we have done to achieve this are explained below: | |
| − | + | *First we have used the JAXB to create Java POJOs to represent SDT types. Here, StudentData and Institute are JAXB POJOs representing corresponding structured data types. | |
| + | *Then we used these POJOs and initialized them with required values. | ||
| + | *Once JAXB POJOs are initialized, we use the utility class (explained below) to serialize the POJOs into XML form. | ||
| − | + | '''Note:''' To make these JAXB POJOs available in your project you will have to export your structured types as XSD, generate the classes from them and copy those classes into your project. For exporting structured types as XSD and generating the classes from it, refer the product documentation. | |
| − | + | '''JAXB Object to XML Conversion''' | |
| − | + | The utility method, given below, converts JAXB object to required org.w3c.dom.Element. This method is generic enough to take in any JAXB object and convert it into XML Element. The method source code is given below. | |
<source lang="Java"> | <source lang="Java"> | ||
Latest revision as of 01:43, 29 February 2012
Contents
Introduction
Currently, Stardust WS API expects out data in the form of ParametersXto which in turn takes list of ParameterXto. This ParameterXto is easy to use for primitive data types, but for structure data type (SDT) we (WS Client) further need to create new XmlValueXto with some implementation of org.w3c.dom.Element with children and/or attributes to form required xml structure.
Here one creates the implementation of the Element, and populate the required xml structure (as per your process SDT) and pass it to XmlValueXto and finally, pass the ParametersXto to the completeActivity method as out data. All this is not easy for WS consumer to deal with and can be avoided with the approach mentioned in this article.
This article provides the work around and utility code for Stardust WS consumers to enable them to use SDTs as JAXB objects.
For this article, it is assumed that you have already worked with Stardust WS API.
Example Process
To demonstrate, we will use the following process. There are only two activities. The first activity updates structure data types, StudentData and Institute. The second activity just shows the updated data.
The Process
StudData and Institute Sructure Data
The process data of type structured data StudentData and InstituteData are defined by the following XSDs
StudentData XSD:<?xml version="1.0" encoding="UTF-8"?> <xsd:schema xmlns:stu="http://www.infinity.com/bpm/model/WSModelWithSDT/StudentData" xmlns:xsd="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.infinity.com/bpm/model/WSModelWithSDT/StudentData"> <xsd:complexType name="StudentData"> <xsd:sequence> <xsd:element name="fname" type="xsd:string"/> <xsd:element name="lname" type="xsd:string"/> </xsd:sequence> </xsd:complexType> <xsd:element name="StudentData" type="stu:StudentData"/> </xsd:schema>
Institue XSD:
<?xml version="1.0" encoding="UTF-8"?> <xsd:schema xmlns:ins="http://www.infinity.com/bpm/model/WSModelWithSDT/Institute" xmlns:xsd="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.infinity.com/bpm/model/WSModelWithSDT/Institute"> <xsd:complexType name="Institute"> <xsd:sequence> <xsd:element name="name" type="xsd:string"/> <xsd:element name="city" type="xsd:string"/> </xsd:sequence> </xsd:complexType> <xsd:element name="Institute" type="ins:Institute"/> </xsd:schema>
Structured Data Usage on the Stardust WS-API
Usually you can form the required XML element according to the SDT schema mannually and pass it to the API in the form of String object. This is explained by the code snippets below.
Here, 'TakeInSTDAndShow' is the ID of the above shown process. The 'StudData' is the ID of StudentData structured type.
private static void startProcessAndComleteFistActivity() throws BpmFault { ProcessInstanceXto startProcess = workflowService.startProcess( "TakeInSTDAndShow", null, true, null); ActivityInstanceXto activateNextActivityForProcess = workflowService .activateNextActivityForProcess(startProcess.getOid()); ParametersXto outData = new ParametersXto(); ParameterXto para1 = new ParameterXto(); para1.setName("StudData"); // para1.setType(QNameConstants.QN_BASE64BINARY); String xmlValStr = "<StudData>" + "<fname>Ganesh</fname>" + "<lname>Lawande</lname>" + "</StudData>"; // Custom code to get XML/SDT in form of Element Document doc = XmlUtils.parseString(xmlValStr); Element documentElement = doc.getDocumentElement(); // Custom code ends here XmlValueXto xmlVal = new XmlValueXto(); xmlVal.getAny().add(documentElement); para1.setXml(xmlVal); outData.getParameter().add(para1); workflowService.completeActivity(activateNextActivityForProcess .getOid(), null, outData, true); }
Structured Data Types as JAXB Objects
As explained in the previous section, forming XML data elements manually is very tedious and error prone task expecially for complex SDT.
In this section we will see that how we can use the JAXB here to make life easier. Take a look at code snippets below;
private static void startProcessAndComleteFistActivityWithJaxbClass() throws BpmFault, IOException, JAXBException { ProcessInstanceXto startProcess = workflowService.startProcess( "TakeInSTDAndShow", null, true, null); ActivityInstanceXto activateNextActivityForProcess = workflowService .activateNextActivityForProcess(startProcess.getOid()); Institute institute = new Institute(); institute.setName("Pune university of applied sciences"); institute.setCity("Pune"); StudentData studentData = new StudentData(); studentData.setFname("Tanaji"); studentData.setLname("BB"); ParameterXto para1 = new ParameterXto(); para1.setName("InstituteData"); para1.setType(QNameConstants.QN_BASE64BINARY); XmlValueXto xmlVal1 = new XmlValueXto(); xmlVal1.getAny().add(JaxbParserUtility.getAsElement(institute)); para1.setXml(xmlVal1); ParameterXto para2 = new ParameterXto(); para2.setName("StudData"); para2.setType(QNameConstants.QN_BASE64BINARY); XmlValueXto xmlVal2 = new XmlValueXto(); xmlVal2.getAny().add(JaxbParserUtility.getAsElement(studentData)); para2.setXml(xmlVal2); ParametersXto outData = new ParametersXto(); outData.getParameter().add(para1); outData.getParameter().add(para2); workflowService.completeActivity(activateNextActivityForProcess .getOid(), null, outData, true); }
If you noticed, here we have replaced the manual task of forming XML elements with JAXB objects. The changes we have done to achieve this are explained below:
- First we have used the JAXB to create Java POJOs to represent SDT types. Here, StudentData and Institute are JAXB POJOs representing corresponding structured data types.
- Then we used these POJOs and initialized them with required values.
- Once JAXB POJOs are initialized, we use the utility class (explained below) to serialize the POJOs into XML form.
Note: To make these JAXB POJOs available in your project you will have to export your structured types as XSD, generate the classes from them and copy those classes into your project. For exporting structured types as XSD and generating the classes from it, refer the product documentation.
JAXB Object to XML Conversion
The utility method, given below, converts JAXB object to required org.w3c.dom.Element. This method is generic enough to take in any JAXB object and convert it into XML Element. The method source code is given below.
package com.sungard.ipp.bootcamp.ws.client; import java.io.ByteArrayOutputStream; import java.io.IOException; import javax.xml.bind.JAXBContext; import javax.xml.bind.JAXBException; import javax.xml.bind.Marshaller; import org.w3c.dom.Element; import ag.carnot.utils.xml.XmlUtils; public final class JaxbParserUtility { public static Element getAsElement(Object dataObj) throws JAXBException, IOException { JAXBContext jc = JAXBContext.newInstance(dataObj.getClass() .getPackage().getName()); Marshaller m = jc.createMarshaller(); ByteArrayOutputStream out = new ByteArrayOutputStream(); m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE); m.marshal(dataObj, out); out.close(); String tempStr = new String(out.toByteArray()); Element elementSDT = XmlUtils.parseString(tempStr).getDocumentElement(); return elementSDT; } }