3.0 Pre-requisites for Java Mapping
For Java mapping there is no development tool support in XI. It is expected that they are developed using external development tools like Eclipse, Jdeveloper, etc. To make the mapping available for the integration server, they have to be imported into the integration repository as JAR files (JAR: Java Archives).
To be able to write a mapping program in your Java development environment, the Java runtime environment (JRE) of the SAP J2EE server must be consistent with the JRE version of your Java development environment. The developer should also be aware of the java APIs which are to be used within a mapping program. Since the program has to deal with an XML input, it should understand and parse the data within the XML InputStream so that it could manipulate it as per the requirement. Currently the most popular parser APIs available for manipulating the XML Documents are SAX and DOM.
The java APIs which are to be used within a mapping program are;
3.1 Mapping API
The runtime environment for Java mappings has a mapping API. To use Java mapping, you must define a Java class that implements the Java interface com.sap.aii.mapping.api.StreamTransformation. This interface is available in aii_map_api.jar. It has two methods:
...
● public void execute(java.io.InputStream in, java.io.OutputStream out)
At runtime, the Integration Engine calls this method to execute a mapping. This method contains an input stream for the source document and an output stream for the target document as parameters. These streams are usually XML documents.
● public void setParameter(java.util.Map param)
The Integration Engine transfers parameters to the mapping program with this method. It evaluates these parameters at runtime in the method execute(). This enables you to control the process flow of the mapping.
The transferred object that implements the Java interface java.util.Map contains seven key/value pairs as parameters. These correspond to corresponding fields in the message header. Apart from the MAPPING_TRACE constant, the value objects are of type java.lang.String. The key objects are defined in the class com.sap.aii.mapping.api.StreamTransformationConstants:
import java.io.*;
import org.xml.sax.*;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.SAXParser;
public class JSAXMapping extends DefaultHandler
{
...
}
To setup the Parser, following steps are to be carried out.
DefaultHandler handler = this;
SAXParserFactory factory = SAXParserFactory.newInstance();
try {
out = new OutputStreamWriter (System.out, "UTF8");
SAXParser saxParser = factory.newSAXParser();
saxParser.parse(in, handler);
} catch (Throwable t) {
t.printStackTrace ();
}
These things have to be followed.
<b>Reward if useful</b>
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