Tutorial

I have create a separate Java Project "de.vogella.sap.system.model" for the SAP system domain model. This domain model captures all data required to connect to a SAP system.

				
package de.vogella.sap.system.model;

/**
 * Represents a SAP System Immutable object
 * 
 * @author Lars Vogel
 * 
 */
public class SapSystem implements java.lang.Cloneable {
	private final String name;
	private final String host;
	private final String client;
	private final String systemNumber; 
	private final String user;
	private final String password;
	private final String language ="en"; // English will be used as login language 
	

	
/**
	 * Constructor, Login language is assumed to be English
	 * @param name
	 * @param client
	 * @param user
	 * @param password
	 * @param host
	 * @param systemNumber
	 */
	public SapSystem(String name, String host, String client
			 , String systemNumber, String user, String password) {
				this.name = name;
				this.client = client;
				this.user = user;
				this.password = password;
				this.host = host;
				this.systemNumber = systemNumber;
	}
	

	public String getName() {
		return name;
	}

	public String getClient() {
		return client;
	}

	public String getUser() {
		return user;
	}

	public String getPassword() {
		return password;
	}

	public String getLanguage() {
		return language;
	}

	public String getHost() {
		return host;
	}

	public String getSystemNumber() {
		return systemNumber;
	}

	@Override
	public String toString() {
		return "Client " + client + " User " + user + " PW " + password
				+ " Language " + language + " Host " + host + " SysID "
				+ systemNumber;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((client == null) ? 0 : client.hashCode());
		result = prime * result + ((host == null) ? 0 : host.hashCode());
		result = prime * result
				+ ((language == null) ? 0 : language.hashCode());
		result = prime * result + ((name == null) ? 0 : name.hashCode());
		result = prime * result
				+ ((password == null) ? 0 : password.hashCode());
		result = prime * result
				+ ((systemNumber == null) ? 0 : systemNumber.hashCode());
		result = prime * result + ((user == null) ? 0 : user.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		SapSystem other = (SapSystem) obj;
		if (client == null) {
			if (other.client != null)
				return false;
		} else if (!client.equals(other.client))
			return false;
		if (host == null) {
			if (other.host != null)
				return false;
		} else if (!host.equals(other.host))
			return false;
		if (language == null) {
			if (other.language != null)
				return false;
		} else if (!language.equals(other.language))
			return false;
		if (name == null) {
			if (other.name != null)
				return false;
		} else if (!name.equals(other.name))
			return false;
		if (password == null) {
			if (other.password != null)
				return false;
		} else if (!password.equals(other.password))
			return false;
		if (systemNumber == null) {
			if (other.systemNumber != null)
				return false;
		} else if (!systemNumber.equals(other.systemNumber))
			return false;
		if (user == null) {
			if (other.user != null)
				return false;
		} else if (!user.equals(other.user))
			return false;
		return true;
	}

	@Override
	public Object clone() {
		try {
			return super.clone();
		} catch (CloneNotSupportedException e) {
			e.printStackTrace();
		}
		return null;
	}

}

			

Create the Java project "de.vogella.sap.rfc.core" for the following Java classes. Create a folder "lib". Add "sapjco3.jar" and the "sapjco3.dll" to this folder and add the jar to the project build path .

The class "JCoDestinationManager" requires that you register a System system. The method .getDestination(String s) can then be used to get the connection to a SAP system.

We implement our own class "MyDestinationDataProvider" which uses an instance of SapSystem to configure itself. This class is later registered at "JCoDestinationManager".

				
package de.vogella.sap.rfc.core.connection;

import java.util.Properties;

import com.sap.conn.jco.ext.DestinationDataEventListener;
import com.sap.conn.jco.ext.DestinationDataProvider;

import de.vogella.sap.system.model.SapSystem;

/**
 * Represents the destination to a specific SAP system. 
 * The destination is maintained via a property file
 * 
 */
public class MyDestinationDataProvider implements DestinationDataProvider {
	static String SAP_SERVER = "SAP_SERVER";
	private final Properties ABAP_AS_properties;

	public MyDestinationDataProvider(SapSystem system) {
		Properties properties = new Properties();
		properties.setProperty(DestinationDataProvider.JCO_ASHOST, system
				.getHost());
		properties.setProperty(DestinationDataProvider.JCO_SYSNR, system
				.getSystemNumber());
		properties.setProperty(DestinationDataProvider.JCO_CLIENT, system
				.getClient());
		
		properties.setProperty(DestinationDataProvider.JCO_USER, system
				.getUser());
		properties.setProperty(DestinationDataProvider.JCO_PASSWD, system
				.getPassword());
	
		ABAP_AS_properties = properties;
	}
	
	@Override
	public Properties getDestinationProperties(String system) {
		return ABAP_AS_properties;
	}

	@Override
	public void setDestinationDataEventListener(
			DestinationDataEventListener eventListener) {
	}

	@Override
	public boolean supportsEvents() {
		return false;
	}

}
			

The following class encapsulates the functionality to connect to a SAP system. It allow to access a RFC via getFunction(). The parameter of this function can then be filled. Afterwards you can execute the function via execute().

				
package de.vogella.sap.rfc.core.connection;

import com.sap.conn.jco.JCoContext;
import com.sap.conn.jco.JCoDestination;
import com.sap.conn.jco.JCoDestinationManager;
import com.sap.conn.jco.JCoException;
import com.sap.conn.jco.JCoFunction;
import com.sap.conn.jco.JCoRepository;

import de.vogella.sap.system.model.SapSystem;

/**
 * Connection allows to get and execute SAP functions. The constructor expect a
 * SapSystem and will save the connection data to a file. The connection will
 * also be automatically be established.
 */

public class Connection {
	static String SAP_SERVER = "SAP_SERVER";
	private JCoRepository repos;
	private JCoDestination dest;

	public Connection(SapSystem system) {
		MyDestinationDataProvider myProvider = new MyDestinationDataProvider(system);
		com.sap.conn.jco.ext.Environment
				.registerDestinationDataProvider(myProvider);
		try {
			dest = JCoDestinationManager.getDestination(SAP_SERVER);
			System.out.println("Attributes:");
			System.out.println(dest.getAttributes());
			repos = dest.getRepository();
		} catch (JCoException e) {
			throw new RuntimeException(e);
		}

	}

	
/**
	 * Method getFunction read a SAP Function and return it to the caller. The
	 * caller can then set parameters (import, export, tables) on this function
	 * and call later the method execute.
	 * 
	 * getFunction translates the JCo checked exceptions into a non-checked
	 * exceptions
	 */
	public JCoFunction getFunction(String functionStr) {
		JCoFunction function = null;
		try {
			function = repos.getFunction(functionStr);
		} catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException(
					"Problem retrieving JCO.Function object.");
		}
		if (function == null) {
			throw new RuntimeException("Not possible to receive function. ");
		}

		return function;
	}

	
/**
	 * Method execute will call a function. The Caller of this function has
	 * already set all required parameters of the function
	 * 
	 */
	public void execute(JCoFunction function) {
		try {
			JCoContext.begin(dest);
			function.execute(dest);

		} catch (JCoException e) {
			e.printStackTrace();
		} finally {
			try {
				JCoContext.end(dest);
			} catch (JCoException e) {
				e.printStackTrace();
			}
		}
	}

}

			

Create Java project "de.vogella.sap.rfc.core.test" maintain your project dependencies and write the following test to check if the connection works. I'm calling a simple BAPI which returns the list of users. Other BAPI's can be found in the SAP Transaction "BAPI".

The following uses JUnit to test the connection. See JUnit Tutorial to learn about JUnit.

				
package de.vogella.sap.rfc.core.test;

import static org.junit.Assert.assertTrue;

import org.junit.Test;

import com.sap.conn.jco.JCoFunction;
import com.sap.conn.jco.JCoTable;

import de.vogella.sap.rfc.core.connection.Connection;
import de.vogella.sap.system.model.SapSystem;

public class ConnectionTester {
	static String SAP = "SAP_SERVER";

	@Test
	public void checkConnection() {
		// SAP System
		SapSystem system = new SapSystem("PFT", "pwdf6394.wdf.sap.corp", "600", "76", "mytester", "welcome");
		
		Connection connect = new Connection(system);

		JCoFunction function = connect.getFunction("BAPI_USER_GETLIST");
		function.getImportParameterList().setValue("MAX_ROWS", 10);
		connect.execute(function);
		JCoTable table = function.getTableParameterList().getTable("USERLIST");
		assertTrue("User Tabelle should not be empty", !table.isEmpty());
	}
}